Table of Contents
This is an old revision of the document!
IH: Oiling & Lubrication - Sub-03D
77-85 Oil Pump Parts Lists and Upgrades with Pics
Originated from an article by DirtyCory of the XLFORUM 1) 2)
See the 77-85 Oil Pump section of the Sportsterpedia for pics, dims and more information.
Also on this page below;
Parts List and Upgrades per Oil Pump Assembly
Parts Lists per Catalogs
Total Oil Pump Assemblies
There were 4 different pump assembly listings used on Sportsters from 77-85.
- (26204-75) 1977-1981
- (26204-82) 82 only
- (26204-82A) E83 only
- (26197-83) L83-85
There were 2 different styles of pumps:
- 77-E83
- There were 5 different versions of upgrades / changes from 77-E83
- L83-85
- This upgraded style oil pump was suggested as a replacement for all year models 77-85
(parts specific to the older pumps were now obsolete in the 1985 season)
There were 3 part number changes for the body and cover set.
(with unknown casting changes)
- 77-81: (26484-75) Oil pump body, (26486-75) Pump cover
- 82-E83: (26484-83) Oil pump body, (26486-83) Pump cover
- L83-85 (26484-75A) Oil pump body, (26486-75A) Pump cover
The L83-85 style pump will bolt to any 77-85 engine as it's own assembly.
The 77-E83 style pumps should all have interchangeable internals.
Any of the these may be found at swap meets or online.
The only mounting difference being that you might have to change out or work around the fittings.
45° and 90° fittings were changed in some of the different year model pumps.
- 77-81 style oil pump, (1) 90° return and (1) 45° feed fitting.
- 82-E83 style oil pump, (1) 45° return and (1) 45° feed fitting.
- L83-85 style oil pump, (1) 90° return and (1) 90° feed fitting.
Most parts will interchange between the different pumps with the exception of;
Gerotors:
- Either early or late style gerotor gears may be used with late style (under-cut) oil pump bodies and covers.
- 77-E83 style chamfered gerotor gears may (only) be used with early style oil pump bodies and covers.
(Use of late style gerotor gears in early style oil pump bodies and covers could cause the oil pump to bind up and possible pump failure).
Outer Plate:
The outer plate had a design change at the bore for the gearshaft.
The outer plate seal changed to mate up with the new design.
So, they fit together as a unit.
Either plate matched with it's correct seal will work on 77-85 pumps.
Individual Parts and Pics
Oil Pump Body and Cover
For 77-81 pump assembly
E77:
Special “1600” oil pump stamped with an “O”:
(26484-75) Oil pump body
(26486-75) Pump cover
Late 77-81:
(26484-75) Oil pump body
(26486-75) Pump cover
For 82-E83 pump assembly
(26484-83) Oil pump body
(26486-83) Pump cover
For L83-85 pump assembly
(26484-75A) Oil pump body
(26486-75A) Pump cover
Gearshaft
See also Gear Shaft Dims.
The gear shaft (26488-75) was used from 77-90.
The dims and teeth pitch are all the same on the gear.
However, there are variations of the exact length of the shaft.
Inner Plate
See also;
Inner Plate Dims
The inner plate (26463-77) is the top plate (with the pump installed).
The return gerotors sit on this plate.
It was used in all 77-90 oil pumps.
Inner separator plate installed position (pump upside down).
Outer Plate
See also;
Outer Plate Dims
The outer plate is the bottom plate (with the pump installed).
The feed gerotors sit under this plate.
- (26493-75) was used in 77-82 oil pumps.
- (26493-75A) was an upgrade for the E83 pump assembly.
It also was used in the re-designed L83-85 assemblies as well as all 86-90 oil pumps.
Either will fit 77-90 oil pumps with their respective seals.
Outer plate comparison 7) |
(26493-75)
77-82 outer plate I.D. 0.518“
(26493-75A)
83-90 outer plate I.D. 0.683”
Outer Plate Seal
Gerotors
See also;
Gerotor Dims
- There were 2 different sets of gerotors used in Sportster oil pumps from 77-85.
- 77-E83; Return set (26491-75), Feed set (26492-75).
Discontinued for production models by November of 1982. 10)
Sold for 77-E83 oil pumps through 1984. - L83-85; Return set (26491-83), Feed set (26492-83).
- The -78B parts book lists the original gerotors.
(even though that catalog was written in 1989 after the design change).
The outside gear in each 77-E83 gerotor set was chamfered.
The outside gear in each L83-85 gerotor set was straight cut.
77-E83 - return (26491-75), feed (26492-75)
Late 1983 oil pump assembly design modification
- Late 1983 pump bodies and covers were also under-cut or relieved to accommodate for clearances with the new gerotors.
- The 77-E83 chamfered gerotors have a (.020“ x 45° chamfer or .020”) radius and the same radius is designed into their respective oil pump body / cover.
- The Late 83 pump body and cover has a (.010“ max. radius) undercut for clearance designed into them.
- These modifications limit interchangeability and affect the installation of repair parts:
- Either early style or late style gerotor gears may be used with late style (under-cut) oil pump bodies and covers.
- Only early style chamfered gerotor gears may be used with early style oil pump bodies and covers
(Use of late style gerotor gears in early style oil pump bodies and covers could cause the oil pump to bind up and possible pump failure).
L83-85 - return (26491-83), feed (26492-83)
Check Valve
(26435-76A) L77-85
Made by Circle Seal.
Part # P106-376.
Patent #3626977.
It has an arrow pointing up with FC to the bottom left of the arrow.
- The oil pump check valve had 2 different part numbers.
- The original was (26435-76) in 1977.
- Speculation could say…,
- The original check was for the special “1600” pump (discontinued L77).
- And the upgraded check was for installation in a newer, non publicized, pump casting not cataloged.
- Either way, the upgraded check valve was used through 1985 on IHs.
In search of a comparable check valve
The closest on the Circle Seal website is a 2900 series cartridge check valve.
Click on the 2900 series in the catalog section to the left on the their site.
In the Products-Engineering-Terminology PDF;
Flow capability (Cv=0.55). Flow capability indication commonly accepted by the valve industry. The literal definition is that a component with a Cv of one (1);
Can flow one (1) gallon of water with a ΔP of one (1) PSI.
The calculated results from Cv equations must be considered reasonable approximations only.
Link to the Circle Valve site with comparable dims and specs:
https://catalog.circlevalve.com/item/check-valves/c2900-series-cartridge-check-valve-0-to-3000-psig/cs-c2949b-4q
This one has a back-up O-ring on the valve.
That link came from this XLF thread:
http://xlforum.net/forums/showthread.php?t=1979566&highlight=gerotor&page=2
Oil Pressure Switch
See also;
Tesing the Oil Pressure Switch
More on How the Ironhead Oil Pressure Switch Works
(26554-77) Oil pressure switch (L-77 to 90).
On 77-85 models, it was mounted at the oil pump and later mounted to the filter pad on 86-90 models.
The oil pressure switch was listed in the -77A parts supplement catalog.
However, it was listed as a L77 addition in the -78 parts supplement.
The circumstance of this switch being a late addition is unclear.
However, there was a wiring harness upgrade in 78 and an oil pressure gauge available for 77-78 models.
Double nuts (7638) for the oil pressure switch were also a late addition part #.
(retainer for the wire to the oil light)
Parts List and Upgrades per Oil Pump Assembly
- The information below is a compilation of individual year catalogs plus long year span catalogs.
- There were 2 long year span parts catalogs published for sale as the 78 catalog. Both were written years after 1978;
- The -78A parts catalog was printed in April 1981 and reflects parts available at that time.
- The -78B parts catalog (printed post IH era) was 'copyright 1989' and reflects parts available then.
(namely parts that were available in 1985 or later for the 77-85 oil pump, disregarding some - i.e. gerotors as above)
- 1979 and later parts catalogs only reference prior fitment back to 1979.
(although, many parts will fit 77-78 models) - The -85A catalog is copyright 1990.
1977-1981 oil pump assembly
New Oil pump assembly (26204-75)
Sold for use on 77-81 engines only. Last sold in 1984.
There were 3 different versions of this pump in regards to upgrades.
Upgrades and parts list versions created thereof are shown below.
The assembly has (1) 90° return and (1) 45° feed fitting.
78 Upgrades / Changes
- New parts / numbers from the -78 parts catalog:
- New check valve body O-ring (12042) for the '1600' pump only.
(to account for a possible oversized condition in the check valve bore in the 77 '1600' pump) - New check valve (26435-76A).
- Both the prior and new check valves have the same lower O-ring.
- Discontinued for Parts Order:
- Original check valve (26435-76) no longer available for parts order.
- The 1600 pump is no longer produced.
- Notes:
- 77 check valve body O-ring (26432-76) still available for standard oil pumps.
- The Oil pressure switch (26554-77) was listed in the -77A parts supplement catalog.
- However, it was listed as a L77 addition in the -78 parts supplement.
Previous models had a pressure switch. The circumstance of this switch being a late addition is unclear.
There was a wiring harness upgrade in 78 and oil pressure gauge available for 77-78 models.
- Double nuts (7638) for the oil pressure switch also a late addition part #.
(retainer for the wire to the oil light)
79 Upgrades / Changes
- Discontinued for Parts Order:
- O-ring (12042) no longer available for parts order.
- Notes:
- O-ring (26432-76) now the only one available.
80 Upgrades / Changes
- New parts / numbers:
- Upgraded cover O-ring (26434-76A)
- This O-ring replaces the original and is used in future oil pumps through 1985.
- Discontinued for Parts Order:
- Previous cover O-ring (26434-76) no longer available for parts order.
81 Upgrades / Changes
There were no changes to the oil pump noted in the -81 parts catalog.
82 Upgrades / Changes
New Oil pump assembly (26204-82)
The new assembly has (1) 45° return and (1) 45° feed fitting.
All other parts are the same as the 81 pump.
- New parts / numbers:
- The part number changed for the 4 Allen head mounting bolts (3478) although their size didn't change.
- Discontinued for Parts Order:
- Oil pump mounting bolts (1794).
- Notes:
- The -82 pump assembly apparently was generated to include the new fitting changes.
(basically a 81 pump with new fittings)- This coincides with the oil tank upgrade in 82 (oil line sizes did not change).
- New pump assembly was equipped on 82 models.
- 77-81 oil pump (26204-75), as upgraded, still sold for 81 and prior models (due to the fittings being different in the new assembly).
E83 Upgrades / Changes
New Oil pump assembly (26204-82A)
- New Parts / Numbers:
- This pump assembly replaced 82 pump (26204-82) for E83 models. Includes;
- New oil pump body (26484-83).
- New pump cover (26486-83).
- New outer plate (26493-75A).
- New outer plate seal (12036A).
- Discontinued for Parts Order:
- The 82 oil pump listing (26204-82) no longer available for parts order.
- Notes:
- 77-81 oil pump (26204-75) still being sold for 77-81 models.
- 77-81 parts are sold for 77-82 model pumps.
- New pump assembly was equipped on E83 models and sold as replacement for 82 models.
- Equipped with the upgrades and 45° oil fittings on both the feed and return hose connections.
L83 Upgrades / Changes
New Oil pump assembly (26197-83)
The assembly has (1) 90° return and (1) 90° feed fitting.
The new parts in this pump were not sold separately until 1985.
- New Parts / Numbers:
- Newly designed oil pump assembly (26197-83).
- The gerotor surfaces in the body and the cover are re-designed to accept the L83 gerotors.
Internal modifications limit interchangeability and affect the installation of repair parts.
- Upgraded body O-ring (26432-76A)
- New oil pump body (26484-75A)
- New pump cover (26486-75A)
- Upgraded gerotors (L83-85 for the 26197-83) available for parts order:
- (26491-83) return, set - new part# for 82-85
- (26492-83) feed, set - new part# for 82-85
- The new gerotor gears are fabricated without the chamfered top and bottom on the outer diameters as was with the 77-E1983 gerotors.
- Notes:
- This pump first appeared in the -84 parts catalog as a replacement assembly unit.
- It's upgraded replacement parts became available through the -85 parts catalog.
- During the transition to the L83 oil pump, the MoCo was still producing oil pumps for earlier models:
- Date references:
- 99451-84 parts catalog: (copyright August-83).
- TSB M-860 dated 11-12-1982 (E83 season).
- The MoCo announces the gerotor gears were then being fabricated without the chamfered top and bottom on the outer diameters.
- TSB M-892 dated 6-22-1984.
- The MoCo announces the retirement of the 77-E83 oil pump assembly.
84 Upgrades / Changes
- Discontinued for Parts Order:
- E83 Oil pump assembly (26204-82A) no longer available for parts order.
- Notes:
- Oil pump assembly (26204-75) and it's upgraded parts still sold for 77-81 models.
- L83 pump (26197-83) and it's new parts now sold as an assembly only for 82 and up replacement.
- All parts were still being sold for the 82-E83 and 77-81 pumps.
85 Upgrades / Changes
- Discontinued for Parts Order:
- 77-81 Oil pump assembly (26204-75) no longer available for parts order.
- Oil pump body (26484-83) no longer available for parts order.
- Pump Cover (26486-83) no longer available for parts order.
- Old gerotor set (26492-75) and (26491-75) no longer available for parts order.
- Notes:
- L83 oil pump assembly (26197-83) now being sold for 79-85 replacement.
(as well as shared individual parts along the way with the exception of the E83 gerotors) - L83 gerotors now being sold for 82 and up.
(since you could only now buy the L83 pump body and cover)
Reflections from the later parts catalogs
-78A (April 1981):
- Lists only parts upgraded by 1981.
-78B (copyright 1989):
- Oil pump “kit” (26197-83) sold for 77 and up models.
- No parts available for any of the prior part specific assemblies.
-85A (copyright 1990):
- Lists the exact same parts as the -85 catalog.
-86 thru -90:
All the parts below are the same as the 85 pump except gerotors;
The -83 return gears are the same but the feed gears had a change.
- Outer plate 26493-75A
- Outer plate seal 12036A
- Spring washer 26461-77
- Gearshaft 26488-75
- Gearshaft pins 26480-77
- Gearshaft retaining ring 26497-75
- Bushing for the pump body 26489-75
- Bushing for the cover 26431-76
- Cover O-ring 26434-76A
- Inner plate 26463-77
- Pump mounting gasket 26495-75
- 90° Return fitting 26496-75
- Return gerotors 26491-83
(feed gerotors changed, 26492-86).
77-E83 Oil Pump Assembly
(26204-75) 77-81
- Notes:
- Retainer nuts for the oil pressure switch connector.
- There was no mention of the nuts on the oil pressure switch.
- Most likely OEM on 77 models and offered for replacement parts in 78?
- The -78A parts catalog shows them as a L77 part. 23)
- Gerotors.
- Both feed and scavenge gerotors have a chamfered radius (.020“ x 45° chamfer or .020”) on each outside gearset.
- The same radius is designed into their respective oil pump body and cover.
- The gerotor part numbers were used from 77-E83.
- However, there was a TSB 24) regarding the early feed gerotors.
- The feed gerotors fit inside the oil pump cover and should extend .001” - .005“ above the ridge.
- This bulletin also says the later feed gerotors should extend up to .011” above the ridge.
- It is unclear at this point what the difference would have been between the early and late feed gerotors by June of 1977.
- However, the part number did not change.
- The special “1600” oil pump.
- From the Sportsterpedia history section, There was a special “1600” oil pump installed on E1000 engines. 25)
- This special (77 only) pump is not listed as a separate item in any of the parts catalogs or supplements.
- It's possible this was a vendor quality control issue on their casting.
- A quantity of them had oversized oil pump body 0-rings (which are assembled in the groove in the check valve bore to seal the pump cover).
- This oversize 0-ring (12042) must be used in place of the standard 0-ring (26432-76) on these pumps only.
- All such special pumps are identified with the letter “0” stamped on the pump body (exact location unknown).
- So, the “1600” oil pump (body at least) appears to be the original casting on 77 models.
- However, it's exact origin and demise is still unclear.
77 Version
Part # | Description |
(1794) | Oil pump mounting bolt (1/4”x20x2/12“ Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4”x9/16“x1/32”) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4“) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) L77 | Oil pressure nut (10-32×1/8”x3/8“ hex)- (2) |
(12036) | Outer plate seal (between the gerotors) |
(12042) 78 | O-ring, body (seals the check valve in the pump body) 1977 - 1600 pump only |
(26204-75) | Oil pump assembly |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76) | Cover O-ring (between the pump halves) |
(26435-76) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-75) | Oil pump body |
(26486-75) | Pump cover (fitted with 45° oil fitting) |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-75) | Return gerotor set (thick ones) |
(26492-75) | Feed gerotor set (thin ones) |
(26493-75) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26496-75) | 90° Return fitting (3/8” hose nipple) |
(26497-75) | Gear shaft retaining ring |
(26554-77) L77 | Oil pressure switch |
(63540-62) | 45° feed fitting (3/8“ hose nipple) |
78-79 Version
Part # | Description |
(1794) | Oil pump mounting bolt (1/4”x20x2/12“ Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4”x9/16“x1/32”) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4“) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) | Oil pressure nut (10-32×1/8”x3/8“ hex)- (2) |
(12036) | Outer plate seal (between the gerotors) |
(26204-75) | Oil pump assembly |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76) | Cover O-ring (between the pump halves) |
(26435-76A) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-75) | Oil pump body |
(26486-75) | Pump cover (fitted with 45° oil fitting) |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-75) | Return gerotor set (thick ones) |
(26492-75) | Feed gerotor set (thin ones) |
(26493-75) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26496-75) | 90° Return fitting (3/8” hose nipple) |
(26497-75) | Gear shaft retaining ring |
(26554-77) | Oil pressure switch |
(63540-62) | 45° Feed fitting (3/8“ hose nipple) |
80-81 Version
Part # | Description |
(1794) | Oil pump mounting bolt (1/4”x20x2/12“ Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4”x9/16“x1/32”) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4“) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) | Oil pressure nut (10-32×1/8”x3/8“ hex)- (2) |
(12036) | Outer plate seal (between the gerotors) |
(26204-75) | Oil pump assembly |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76A) | Cover O-ring (between the pump halves) |
(26435-76A) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-75) | Oil pump body |
(26486-75) | Pump cover (fitted with 45° oil fitting) |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-75) | Return gerotor set (thick ones) |
(26492-75) | Feed gerotor set (thin ones) |
(26493-75) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26496-75) | 90° Return fitting (3/8” hose nipple) |
(26497-75) | Gear shaft retaining ring |
(26554-77) | Oil pressure switch |
(63540-62) | 45° Feed fitting (3/8“ hose nipple) |
(26204-82) 82
One year production assembly.
The assembly has a 45° feed fitting and a 45° return fitting.
This coincides with the oil tank upgrade in 82.
82 Version
Part # | Description |
(3478) | Oil pump mounting bolt (1/4”x20x2/12“ Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4”x9/16“x1/32”) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4“) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) | Oil pressure nut (10-32×1/8”x3/8“ hex)- (2) |
(12036) | Outer plate seal (between the gerotors) |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76A) | Cover O-ring (between the pump halves) |
(26435-76A) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-75) | Oil pump body |
(26486-75) | Pump cover (fitted with 45° oil fitting) |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-75) | Return gerotor set (thick ones) |
(26492-75) | Feed gerotor set (thin ones) |
(26493-75) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26497-75) | Gear shaft retaining ring |
(26554-77) | Oil pressure switch |
(63540-62) | 45° feed and return fittings (3/8” hose nipple) |
(26204-82A) E83
Production assembly for E83 models.
The assembly has a 45° feed fitting and a 45° return fitting.
E83 Version
Part # | Description |
(3478) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) |
(12036A) | Outer plate seal (between the gerotors) |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76A) | Cover O-ring (between the pump halves) |
(26435-76A) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-83) | Oil pump body |
(26486-83) | Pump cover (fitted with 45° oil fitting) |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-75) | Return gerotor set (thick ones) |
(26492-75) | Feed gerotor set (thin ones) |
(26493-75A) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26497-75) | Gear shaft retaining ring |
(26554-77) | Oil pressure switch |
(63540-62) | 45° feed and return fittings (3/8“ hose nipple) |
L83-85 Oil Pump Assembly
(26197-83) L1983-85
L83-85 production assembly.
The assembly has a 90° feed fitting and a 90° return fitting.
This coincides with the oil tank upgrade in 84 (or possibly L83).
L83-85 Version
Part # | Description |
(3478) | Oil pump mounting bolt (1/4”x20x2/12“ Allen head) - (4) |
(6242W) | Oil pump mounting bolt washer (1/4”x9/16“x1/32”) - (4) |
(7036) | Oil pump mounting bolt lockwasher (1/4“) - (4) |
(7069) | Oil pressure switch lockwasher (#10) - (2) |
(7638) | Oil pressure nut (10-32×1/8”x3/8“ hex)- (2) |
(12036A) | Outer plate seal (between the gerotors) |
(26430-76) | Gear shaft pin |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) |
(26432-76A) | O-ring, body (seals the check valve in the pump body) |
(26433-77) | Lower O-ring |
(26434-76A) | Cover O-ring (between the pump halves) |
(26435-76A) | Check valve |
(26461-77) | Spring washer (between the two plates) |
(26463-77) | Inner plate (return gerotors sit on this plate) |
(26480-77) | Roll pin |
(26484-75A) | Oil pump body |
(26486-75A) | Pump cover |
(26488-75) | Gear shaft |
(26489-75) | Pump body bushing (AKA upper shaft bushing) |
(26491-83) | Return gerotor set (thick ones) |
(26492-83) | Feed gerotor set (thin ones) |
(26493-75A) | Outer plate (sits on top of the feed gerotors) |
(26495-75) | Gasket (pump to engine case) |
(26496-75) | 90° Return and feed fittings (3/8” hose nipple) |
(26497-75) | Gear shaft retaining ring |
(26554-77) | Oil pressure switch |
Parts Lists per Catalogs
This is a compilation of period correct parts cataogs for 77-85 oil pumps.
In addition, the table to the right lists which and how many years each part was used.
New part numbers in each year are highlighted.
All catalogs from 79 and up only list parts to retrofit back to 1979.
However, the chronological list below reveals that 79- means 77- for the most part.
Period correct catalogs;
- 99451-77A supplement catalog
- 99451-78 supplement catalog
- 99451-79 catalog
- 99451-79A catalog
- 99451-80 catalog
- 99451-81 catalog
- 99451-82 catalog
- 99451-83 catalog
- 99451-84 catalog
- 99451-85 catalog
Later year catalogs also referenced;
Some of the parts listed in the later catalogs will be different than the period correct ones.
These catalogs reflect parts that were available at the time of printing.
(which may be upgrades instead original parts).
- 99451-78A (1981)
- 99451-78B (1989)
- 99451-85A (1990)
The -78B and -85A catalogs list the new body and outer plate parts only.
All the parts are for 77-85 pumps which is true.
- Oil pump body (26484-83)
- Pump Cover (26486-83)
- The new body and cover will retro to 77-85 pump (internals).
- Outer plate (26493-75A
- Outer plate seal (12036A)
- The new outer plate will also retrofit to 77-85 pumps (together with updated seal).
But, the only listing for gerotors are the E83 gearset (26492-75) and (26491-75).
It appears the MoCo only offered the L83 gerotors (by themselves) for a limited time after the 1985 season.
Afterwards, the L83 gearset could only be found new in the -83 pump assembly.
The only pump assembly is the 26197-83 as an oil pump “kit” with no way to order the gerotors that fit in it.
(possibly to help to keep them from being installed in the earlier pumps)
1977 Oil Pump
Parts list from the -77A and -78 parts catalog supplements: 26) 27)
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(1794) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 77 | 77-81 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 77 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 77 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | Late 77 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | Late 77 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 77 | 77-82 |
(12042) | O-ring, body (seals the check valve in the pump body) (from -78) | 77 only | 77 - 1600 pump only |
(26204-75) | Oil pump assembly | 77 | 77-81 |
(26430-76) | Gear shaft pin | 77 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 77 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 77 | 77-84 |
(26433-77) | Lower O-ring | 77 | 77-85 |
(26434-76) | Cover O-ring (between the pump halves) | 77 | 77-79 |
(26435-76) | Check valve | 77 | 77 only |
(26461-77) | Spring washer (between the two plates) | 77 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 77 | 77-85 |
(26480-77) | Roll pin | 77 | 77-85 |
(26484-75) | Oil pump body | 77 | 77-82 |
(26486-75) | Pump cover | 77 | 77-82 |
(26488-75) | Gear shaft | 77 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 77 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 77 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 77 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 77 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 77 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 77 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 77 | 77-85 |
(26554-77) | Oil pressure switch (from -78) | Late 77-78 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 77 | 77-E83 |
45° Return fitting | (not listed) | 82-E83 |
1978 Oil Pump
Parts list from the -78 parts catalog supplement: 28)
Part # changes in the table below are highlighted.
(although HD has changed parts without changing the part numbers)
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(1794) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 77-78 | 77-81 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 77-78 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 77-78 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | Late 77-78 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | Late 77-78 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 77-78 | 77-82 |
(12042) | O-ring, body (seals the check valve in the pump body) | 77 only | 77 - 1600 pump only |
(26204-75) | Oil pump assembly | 77-78 | 77-81 |
(26430-76) | Gear shaft pin | 77-78 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 77-88 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 77-78 | 77-84 |
(26433-77) | Lower O-ring | 77-78 | 77-85 |
(26434-76) | Cover O-ring (between the pump halves) | 77-78 | 77-79 |
(26435-76A) | Check valve | 77-78 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 77-78 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 77-78 | 77-85 |
(26480-77) | Roll pin | 77-78 | 77-85 |
(26484-75) | Oil pump body | 77-78 | 77-82 |
(26486-75) | Pump cover | 77-78 | 77-82 |
(26488-75) | Gear shaft | 77-78 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 77-78 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 77-78 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 77-78 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 77-78 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 77-78 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 77-78 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 77-78 | 77-85 |
(26554-77) | Oil pressure switch | Late 77-78 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 77-78 | 77-E83 |
45° Return fitting | (not listed) | 82-E83 |
1979 Oil Pump
Parts list from the -79 parts catalog: 29)
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(1794) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79 | 77-81 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79 | 77-82 |
(26204-75) | Oil pump assembly | 79 | 77-81 |
(26430-76) | Gear shaft pin | 79 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79 | 77-84 |
(26433-77) | Lower O-ring | 79 | 77-85 |
(26434-76) | Cover O-ring (between the pump halves) | 79 | 77-79 |
(26435-76A) | Check valve | 79 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79 | 77-85 |
(26480-77) | Roll pin | 79 | 77-85 |
(26484-75) | Oil pump body | 79 | 77-82 |
(26486-75) | Pump cover | 79 | 77-82 |
(26488-75) | Gear shaft | 79 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 79 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 79 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 79 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79 | 77-85 |
(26554-77) | Oil pressure switch | 79 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79 | 77-E83 |
45° Return fitting | (not listed) | 82-E83 |
1980 Oil Pump
Parts list from the -80 parts catalog: 30)
Part # changes in the table below are highlighted.
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(1794) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-80 | 77-81 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-80 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-80 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-80 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-80 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-80 | 77-82 |
(26204-75) | Oil pump assembly | 79-80 | 77-81 |
(26430-76) | Gear shaft pin | 79-80 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-80 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79-80 | 77-84 |
(26433-77) | Lower O-ring | 79-80 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-80 | 80-85 |
(26435-76A) | Check valve | 79-80 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-80 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-80 | 77-85 |
(26480-77) | Roll pin | 79-80 | 77-85 |
(26484-75) | Oil pump body | 79-80 | 77-82 |
(26486-75) | Pump cover | 79-80 | 77-82 |
(26488-75) | Gear shaft | 79-80 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-80 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79-80 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 79-80 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 79-80 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 79-80 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-80 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-80 | 77-85 |
(26554-77) | Oil pressure switch | 79-80 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-80 | 77-E83 |
45° Return fitting | (not listed) | 82-E83 |
1981 Oil Pump
- Notes:
- There are no changes noted in the -81 parts catalog.
Parts list from the -81 parts catalog: 31)
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(1794) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-81 | 77-81 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-81 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-81 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-81 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-81 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-81 | 77-82 |
(26204-75) | Oil pump assembly | 79-81 | 77-81 |
(26430-76) | Gear shaft pin | 79-81 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-81 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79-81 | 77-84 |
(26433-77) | Lower O-ring | 79-81 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-81 | 80-85 |
(26435-76A) | Check valve | 79-81 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-81 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-81 | 77-85 |
(26480-77) | Roll pin | 79-81 | 77-85 |
(26484-75) | Oil pump body | 79-81 | 77-82 |
(26486-75) | Pump cover | 79-81 | 77-82 |
(26488-75) | Gear shaft | 79-81 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-81 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79-81 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 79-81 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 79-81 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 79-81 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-81 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-81 | 77-85 |
(26554-77) | Oil pressure switch | 79-81 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-81 | 77-E83 |
45° Return fitting | (not listed) | 82-E83 |
1982 Oil Pump
Parts list from the -82 parts catalog: 32)
Part # changes in the table below are highlighted.
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(3478) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-82 | 82-85 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-82 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-82 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-82 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-82 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-82 | 77-82 |
(26204-75) | Oil pump assembly | 79-81 | 77-81 |
(26204-82) | Oil pump assembly | 82 | 82 only |
(26430-76) | Gear shaft pin | 79-82 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-82 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79-82 | 77-84 |
(26433-77) | Lower O-ring | 79-82 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-82 | 80-85 |
(26435-76A) | Check valve | 79-82 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-82 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-82 | 77-85 |
(26480-77) | Roll pin | 79-82 | 77-85 |
(26484-75) | Oil pump body | 79-82 | 77-82 |
(26486-75) | Pump cover | 79-82 | 77-82 |
(26488-75) | Gear shaft | 79-82 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-82 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79-82 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 79-82 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 79-82 | 77-82 |
(26495-75) | Gasket (pump to engine case) | 79-82 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-81 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-82 | 77-85 |
(26554-77) | Oil pressure switch | 79-82 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-82 | 77-E83 |
45° Return fitting | 82 | 82-E83 |
1983 Oil Pump
Parts list from the -83 parts catalog: 33)
Part # changes in the table below are highlighted.
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(3478) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-83 | 82-85 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-83 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-83 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-83 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-83 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-82 | 77-82 |
(12036A) | Outer plate seal (between the gerotors) | 83 | 83-85 |
(26204-75) | Oil pump assembly | 79-81 | 77-81 |
(26204-82A) | Oil pump assembly | 82-83 | 83 only |
(26430-76) | Gear shaft pin | 79-83 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-83 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79-83 | 77-84 |
(26433-77) | Lower O-ring | 79-83 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-83 | 80-85 |
(26435-76A) | Check valve | 79-83 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-83 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-83 | 77-85 |
(26480-77) | Roll pin | 79-83 | 77-85 |
(26484-75) | Oil pump body | 79-82 | 77-82 |
(26484-83) | Oil pump body | 83 | 83-84 |
(26486-75) | Pump cover | 79-83 | 77-82 |
(26486-83) | Pump cover | 83 | 83-84 |
(26488-75) | Gear shaft | 79-83 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-83 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79-83 | 77-E83 |
(26492-75) | Feed gerotor set (thin ones) | 79-83 | 77-E83 |
(26493-75) | Outer plate (sits on top of the feed gerotors) | 79-82 | 77-82 |
(26493-75A) | Outer plate (sits on top of the feed gerotors) | 83 | 83-85 |
(26495-75) | Gasket (pump to engine case) | 79-83 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-81 | 77-81 L83-85 |
90° Feed fitting | (not listed) | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-83 | 77-85 |
(26554-77) | Oil pressure switch | 79-83 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-83 | 77-E83 |
45° Return fitting | 82-83 | 82-E83 |
1984 Oil Pump
Parts list from the -84 parts catalog: 34)
Part # changes in the table below are highlighted.
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(3478) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-84 | 82-85 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-84 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-84 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-84 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-84 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-82 | 77-82 |
(12036A) | Outer plate seal (between the gerotors) | 79-84 | 83-85 |
(26197-83) | Oil pump assembly Late 83 oil pump assembly. | 82-84 | L83-85 |
(26204-75) | Oil pump assembly | 79-81 | 77-81 |
(26430-76) | Gear shaft pin | 79-84 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-84 | 77-85 |
(26432-76) | O-ring, body (seals the check valve in the pump body) | 79-84 | 77-84 |
(26433-77) | Lower O-ring | 79-84 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-84 | 80-85 |
(26435-76A) | Check valve | 79-84 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-84 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-84 | 77-85 |
(26480-77) | Roll pin | 79-84 | 77-85 |
(26484-75) | Oil pump body | 79-82 | 77-82 |
(26484-83) | Oil pump body | 83-84 | 83-84 |
(26486-75) | Pump cover | 79-82 | 77-82 |
(26486-83) | Pump cover | 83-84 | 83-84 |
(26488-75) | Gear shaft | 79-84 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-84 | 77-85 |
(26491-75) | Return gerotor set (thick ones) | 79-84 | 77-E-83 |
(26492-75) | Feed gerotor set (thin ones) | 79-84 | 77-E83 |
(26493-75A) | Outer plate (sits on top of the feed gerotors) | 79-84 | 83-85 |
(26495-75) | Gasket (pump to engine case) | 79-84 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-81 L83-84 | 77-81 L83-85 |
90° Feed fitting | L83-84 | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-84 | 77-85 |
(26554-77) | Oil pressure switch | 79-84 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-E83 | 77-E83 |
45° Return fitting | 82-E83 |
1985 Oil Pump
Parts list from the -85 parts catalog: 35)
Part # changes in the table below are highlighted.
Part # | Description | Listed for Year(s) | Factory Installed On Year(s) |
(3478) | Oil pump mounting bolt (1/4“x20x2/12” Allen head) - (4) | 79-85 | 82-85 |
(6242W) | Oil pump mounting bolt washer (1/4“x9/16”x1/32“) - (4) | 79-85 | 77-85 |
(7036) | Oil pump mounting bolt lockwasher (1/4”) - (4) | 79-85 | 77-85 |
(7069) | Oil pressure switch lockwasher (#10) - (2) | 79-85 | 77-85 |
(7638) | Oil pressure nut (10-32×1/8“x3/8” hex)- (2) | 79-85 | 77-85 |
(12036) | Outer plate seal (between the gerotors) | 79-82 | 77-82 |
(12036A) | Outer plate seal (between the gerotors) | 83-85 | 83-85 |
(26197-83) | Oil pump assembly Late 83 oil pump assembly. | 79-85 | L83-85 |
(26430-76) | Gear shaft pin | 79-85 | 77-85 |
(26431-76) | Pump cover bushing (AKA lower shaft bushing) | 79-85 | 77-85 |
(26432-76A) | O-ring, body (seals the check valve in the pump body) | 79-85 | 85 |
(26433-77) | Lower O-ring | 79-85 | 77-85 |
(26434-76A) | Cover O-ring (between the pump halves) | 79-85 | 80-85 |
(26435-76A) | Check valve | 79-85 | 77-85 |
(26461-77) | Spring washer (between the two plates) | 79-85 | 77-85 |
(26463-77) | Inner plate (return gerotors sit on this plate) | 79-85 | 77-85 |
(26480-77) | Roll pin | 79-85 | 77-85 |
(26484-75A) | Oil pump body | 79-85 | L83-85 |
(26486-75A) | Pump cover | 79-85 | L83-85 |
(26488-75) | Gear shaft | 79-85 | 77-85 |
(26489-75) | Pump body bushing (AKA upper shaft bushing) | 79-85 | 77-85 |
(26491-83) | Return gerotor set | 82-85 | L83-85 |
(26492-83) | Feed gerotor set | 82-85 | L83-85 |
(26493-75A) | Outer plate (sits on top of the feed gerotors) | 79-85 | 83-85 |
(26495-75) | Gasket (pump to engine case) | 79-85 | 77-85 |
(26496-75) | 90° Return fitting (3/8“ hose nipple) | 79-81 L83-85 | 77-81 L83-85 |
90° Feed fitting | L83-85 | L83-85 | |
(26497-75) | Gear shaft retaining ring | 79-85 | 77-85 |
(26554-77) | Oil pressure switch | 79-85 | 77-85 |
(63540-62) | 45° Feed fitting (3/8” hose nipple) | 79-E83 | 77-E83 |
45° Return fitting | 82-E83 |