Table of Contents
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IH: Engine Mechanicals
See also Crankshaft / Flywheel Tools in the Reference section of the Sportsterpedia.
Sub-Documents
Engine Cases
Year Model | Case Set Part# | Left Case Part# | Left Case Casting# | Right Case Part# | Right Case Casting# |
1957-1965 XL/XLH | 24511-57 | 24532-57 | 24534-57 | 24556-57 | 24558-57 |
Notes | “No hump” cases (primary not cast for electric start) | ||||
1958-1965 XLC/XLCH | 24515-58 | 24532-58 | 24534-57 | 24556-57 | 24558-57 |
Notes | “No hump” cases (primary not cast for electric start). | ||||
1966 XLH | 24511-57 24511-57A | 24532-57 | 24534-57 | 24555-57 24555-57A | 24558-57 |
Notes | “No hump” cases (primary not cast for electric start). E1966 case set (24511-57) replaced by (24511-57A) on 1-13-1966 Factory changes made starting with crankcase# (66 XLCH 6117-up); 1) Right case has fillet added to base of countershaft low gear boss. Right case is replacement for all 1957-1965 models. -57A case set is replacement for 57-66 XL/XLH (24511-57) Left case is replacement for 1957-1966 XL/XLH Case set (24511-57A) replaced by 1969 XLCH case set (24515-58A) in 1969 Left case replaced by XLCH (24532-58) in 1969 for 57-66 XL/XLH |
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1966-1969 XLCH | 24515-58 24515-58A | 24532-58 | 24534-57 | 24555-57 24555-57A | 24558-57 |
Notes | “No hump” cases (primary not cast for electric start). E1966 case set (24515-58) replaced by (24515-58A) on 1-13-1966 Factory changes made (66 XLCH 6117-up); 2) Right case has fillet added to base of countershaft low gear boss. -57A right case is replacement for all 1957-1965 models -58A case set is replacement for 1966 XLH in 1969 |
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1967-1968 XLH | 24512-67 | 24531-67 | 34-67 | 24555-67 | 24558-67 |
Notes | “Hump” cases (primary cast to accept electric starter) | ||||
1969 XLH | 24512-67A | 24532-58 | 34-67 | 24555-67A | 24558-67 |
Notes | “Hump” cases (primary cast to accept electric starter). Right case is replacement for 1967-1968 XLH Case set is also replacement for 1967-1969 XLH |
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1970-1971 XLH/XLCH | 24512-67A | 24531-67 | 34-67 | 24555-67A | 24558-67 |
Notes | 1970 and all future years are “hump” cases for electric start Left case is replacement for 1967-1969 XLH Right case is replacement for 1967-1969 XLH Case set is also replacement for 1967-1969 XLH 1978 parts supplement corrects “used on” models to 70-71 XLCH VIN moved the from the left side case to the right case. A blank Vin pad is still on the left with no number stamped on it. 3) |
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1971 XLCH | 24512-70 | 24531-67 | 24555-70 | ||
Notes | Case set is also replacement for 1970 XLCH. Possible one year only case set (see above) | ||||
1972 XLH/XLCH | 24505-72 | 24535-72 | 24534-72 | 24551-72 | 24558-72 |
Notes | First year for 1000 Sportsters. Last year of the speedometer drive gear in the right case. | ||||
1973-1976 XLH/XLCH | 24505-73 | 24535-73 | 24534-72 | 24551-73 | 24558-73A |
Notes | There was a late 1973 cylinder and head change but the crankcase was left unchanged 4) Starting in 1976, case halves not sold separately |
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1977-1978 XL/XLCH/XLCR | 24527-75 | - | 24534-75 | - | 24558-75 |
Notes | Cases redesigned for a minisump, new oil pump mounting boss, left side shifter Crankcase breathes thru holes in gearcase wall, oil trough for timed breather deleted. Vertical oil scavenge passage drilled in sump wall |
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1979 XL/XLCH | 24527-75A | - | 24534-75 | - | 24558-75 |
Notes | Right case modified to eliminate high pressure oil leakage around the oil passage between the upper crankcase cover and crankcase in November, 1979 5) |
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1979-1980 XLS | 24490-79A | - | 24534-75 | - | 24558-75 |
Notes | Last year cases were cast with hole for kick start. | ||||
1980 XL | 24527-75B | - | 24534-75 | - | 24558-75 |
Notes | Case set is also replacement for 1979 XL/XLCH. | ||||
1981-1982 XL | 24527-81A | - | 24534-81 | - | 24558-75A |
Notes | Sold for 1982-E1984 XL/XLS/XLX in 1985 Must use rear motor mount 16203-82A L1981 to E1982 production change on the right case, all XL models. On some cases, the oil galley slot in the top of the gearcase was not machined. Instead, a hole was drilled thru to connect the oil path. Upper left corner of gearcase also received additional threaded hole to mount the gearcase cover. Left case has a new “hump” casting to mount the new Nippon Denso starter. |
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1981-1982 XLS | 24490-81A | - | 24534-81 | - | 24558-75B |
Notes | Case set is (painted black). See 1981-1982 XL production change above. | ||||
1981-1982 XLS replacement | 24490-81C | - | - | ||
Notes | Replacement (painted black) case for 1981-1982 XLS offered in 1983 Must use rear motor mount 16203-67A on 1981 models Must use rear motor mount 16203-82A on 1982 and 1983 models |
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1982 XLS replacement | 24490-82 | - | - | ||
Notes | Replacement (painted black) case for 1982 XLS offered in 1984 Must use rear motor mount 16203-82A |
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1983 XL/XLS | 24527-81C | - | 24534-83 | - | 24558-83A |
Notes | Replacement case for 1981-1982 XL offered in 1983 Must use rear motor mount 16203-67A on 1981 models See TSB M-876A for more details Must use rear motor mount 16203-82A on 1982 and 1983 models L1983 production change: The roll pin for the trans thrust washer in the case was removed. 6) |
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L1983 XR-1000 | 24517-83 | - | - | ||
Notes | |||||
- | - | ||||
Notes | Case set 24480-84 is listed in 1984 parts book but number was later given to L1984 case set 7) | ||||
E1984 XL/XLS/XLX | 24527-82A | - | 24534-83A | - | 24558-83B |
Notes | Late 1984 production change 8) Case set is also replacement for 82-E84 models Must use rear motor mount 16203-82A New crankcase set starting with crankcase date code 7 84 174011 (June 22, 1984). Features new mainshaft bearing race (35105-83) and new pressed in mainshaft seal (12049). Trans mainshaft/roller bearing/retaining ring remain unchanged Same channel cast into right side of tranny compartment but hole not drilled for stator grommet |
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L1984 XL/XLS/XLX | 24480-84 | - | 24534-83A | - | 24558-83B |
Notes | Production change in 1984 Generator deleted, hole in case there redesigned for oil filter mount Stator mounted to trap door w/ hole in case for wire grommet Channel cast into right side of tranny compartment ending in hole for stator wire grommet |
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1985 XL/XLS/XLX | 24480-85 | - | - | ||
Notes | Originally listed for all 1985 models thru the -85 parts book Sold for Late 1985 thru the -85A parts book Starting with crankcase# (785 303002) a cam gear oiler was installed Right case drilled/tapped between F-R tappets for oiler tube feed oil Gearcase wall tapped to attach oiler tube |
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E1985 XL/XLS/XLX | 24480-85A | - | 24534-83A | - | 24558-83B |
Notes | Sold for Early 1985 thru the -85A parts book |
Flywheel
Sub-Documents
Year Model → Parts ↓ | 1952-1953 K/KK | 1954-1956 K Models | 1957-1971 XL/XLH XLC/XLCH | 1972-1976 XLH/XLCH | 1977-1979 XLH/XLCH/XLS full assembly used until depleted → | 1980-E1981 XL / XLS full assembly used until depleted → | L1981-1985 XL/XLS/XLX |
Flywheel Assembly w/shafts, w/rods | 23900-52 | 23900-54 23900-54A | 23900-57 23900-57A (72) | 23900-57A | 23900-75 | 23900-75A | 23900-75B 23900-75C (83) |
Left Flywheel | 23915-52 | 23916-54 23916-54A | 23916-57 23916-57A (72) | 23916-57A | 23916-57A Keyway | 23916-57A | 23916-80 No keyway |
Right Flywheel | 23935-52 | 23936-54 23936-54A | 23936-57 23936-57A (72) | 23936-57A | 23936-57A Compound oil path | 23936-57A timing marks changed from case# 780-108-001 9) | 23936-80 Single line oil path |
Connecting Rod Assembly w/bearings w/crankpin | 24275-52 | 24275-54 | 24275-57 | 24275-57 | 24275-57 | 24275-57 | 24275-80 |
Rear Rod | 24290-52 | 24290-52 | 24290-57 | 24290-57 | 24290-57 | 24290-57 | 24290-57 |
Front Rod | 24294-52 | 24294-52 | 24294-52 | 24294-52 | 24294-52 | 24294-52 | 24294-52 |
Crankpin | 23960-52 | 23960-54 | 23960-54 | 23960-54 | 23960-54 Oil hole 110° from keyway | 23960-54 | 23960-80 w/ plug Oil hole 90° from keyway |
Crankpin Roller (std) (1 roller) | 9101 (E52) 9381 (L52-53) 9401 (52-53) | 9441 9441A (59) 9150 9150A (59) | 9441 9441A (59) 9150 9150A (59) | 9441A 9150A | 9441A 9150A | 9441A 9150A | 9441A 9150A |
Crankpin Key | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 11218 1/8“ x 3/8” |
Crankpin Boss Washer | 23972-52 | 23972-54 | 23972-57 | 23972-72 | 23972-72 (E79) 6506 (L79) | 6506 | 6506 |
Crankpin Nut | 23967-48 | 23967-54 | 23967-54 23967-54A (71) | 23967-54A | 23967-54A | ||
Crankpin Nut Lock Plate | 24015-36 | 24015-36 (E54) 23971-41 (L54) | 23971-41 | 23971-41 | 23971-41 | ||
Lock Plate Screw | 2669 | 2669 | 2669 11) 2669W (65) | 2669W | |||
Con Rod Rear Roller Retainer | 24362-52 24361-54 | 24362-54 | 24362-54 | 24362-54A | 24362-54A | 24362-54A | 24362-54A |
Con Rod Front Roller Retainer | 24364-52 24361-54 | 24364-54 | 24364-54 | 24364-54A | 24364-54A | 24364-54A | 24364-54A |
Con Rod Rear Bearing Race | 24341-52A (74) | 24341-52A (74) | 24341-52A | 24341-52A | 24341-52A | ||
Con Rod Front Bearing Race | 24352-52A (74) | 24352-52A (74) | 24352-52A (74) | 24352-52A | 24352-52A | 24352-52A | |
Sprocket Shaft | 24000-52 | 24000-54 | 24000-57 | 24000-57 | 24000-75 | 24000-75 Large keyway | 24000-80 12) 24000-81 13) common taper No keyway |
Sprocket Shaft Key | 23985-12 3/16“ x 1/2” | 23985-12 E54 KH 40390-54 L54-56 | 40390-54 | 23985-12 3/16“ x 1/2” | 23985-12 3/16“ x 1/2” | 23985-12 3/16“ x 1/2” | not used |
Gear Shaft | 24005-52 | 24005-54 | 24005-57 | 24005-57 | 24008-75 -77A, -78 3/16“ key | 24008-75A 2-piece 14) | 24005-75 15) 24005-80 16) 1-piece 17) common taper 1/8” key |
Gear Shaft Key | 23985-18 1/8“ x 1/2” | 23985-18 1/8“ x 1/2” | 23985-12 3/16“ x 1/2” | 23985-12 3/16“ x 1/2” | 23985-12 (E79) 11200 (L79) | 11200 18) | 11218 1/8“ x 3/8” |
Sprocket Shaft or Gear Shaft Lock Plate | 24015-36 | 24015-36 | |||||
Lock Plate Screw | 2669 | 2669 | 2669 20) 2669W (65) | 2669W | |||
Sprocket or Gear Shaft Nut | 24003-54 (54-E55) 8011 (54-56) | 8011 | 8011 | 8011 | 8011 | ||
Pinion Gear Nut Tabbed Washer | 7913 7044 | 7913 7044 |
L1981-up Commonized Flywheels
- In May of 1981, the MoCo issued a bulletin stating that product and quality improvements have brought about a commonized flywheel taper design.
All tapers were communized at 6° and all keyways were standardized.
In June of 1981, an update to this bulletin was issued to include part numbers. 21) 22)
- A limited number of E1982 XL engines (782216009-782237017) were assembled without the communized flywheel taper design. 23)
- Notable component changes are included in the chart below.
- This was a running change in 1340cc and 1000cc engines but both new and old designs were used in production until the old stock parts ran out.
- Assembly and disassembly was the same for the old and new style flywheels but the torque values did change for the new style assembly.
However, new and old style components must not be intermixed.
Changes for Sportster 1000 engines include:
New Flywheel - Sprocket Side Gear Side | 23916-80 23936-80 | 'Lazy 8' rear cylinder timing mark and no keyway Single hole oil path. |
The old style flywheel has a keyway on the sprocket side (23916-57A) and a compound (2) hole oil path on the gear side (23936-57A). | ||
New Crankpin | 23960-80 | Oil hole is now 90° to the keyway |
Old style crankpin (23960-54) oil hole was 110° to the keyway | ||
New Crankpin Nuts | 23901-81 | 20/1“ thread pattern at 150-185 ft/lbs. |
Old style crankpin nuts (23967-54A) were 20/1” threads with 150-175 ft/lbs. | ||
New Sprocket Shaft | 24000-80 | No keyway |
Old style sprocket shaft (24000-75) has a large keyway | ||
New Sprocket Shaft Nut | 23902-81 | 3/4“ x 20 threads at 100-120 ft/lbs. |
Old style sprocket shaft nut (8011) has 11/16” x 18 threads at 100-120 ft/lbs. | ||
New Sprocket Shaft Key | Not used | |
Old style sprocket shaft key (23985-12) has a large woodruff key (3/16“ x 1/2”) | ||
New Gear Shaft | 24005-80 | One piece construction |
Old style gear shaft (24008-75A) is of two piece construction | ||
New Gear Shaft Nut | 23902-81 | 3/4“ x 20 threads at 100-120 ft/lbs. |
Old style gear shaft nut (8011) has 11/16” x 18 threads at 100-120 ft/lbs. | ||
New Gear Shaft Key | 11218 | Small woodruff key (1/8“ x 3/8”) |
Old style gear shaft key (11200) has a large woodruff key (3/16“ x 1/2”) | ||
New Crank Key | 11218 | Small woodruff key (1/8“ x 3/8”) |
Old style crank key (23985-18) has a large woodruff key (1/8“ x 1/2”) |
Roller Bearing Inspection (1957-1976)
- In a letter dated May 9, 1977, an HD interoffice memo was sent regarding an inspection of parts stock roller bearings. Some roller bearing part numbers were found to have incorrect diameters. A new micrometer was purchased to remedy this problem.
- Two of those part numbers are gear shaft (9421) and crank pin front rollers (9150A) for Sportsters.
- In light of this oversight, a listing of part numbers with their correct dims and tolerances was issued as in below:
Used for 57-76 Sportster gear shaft roller bearings | Diameter | Size | Length |
---|---|---|---|
9421 | .1876“ - 1974” | Standard | .800“ - .796” |
9422 | .1878“ - 1876” | + .0002“ | .800” - .796“ |
9423 | .1880” - .1878“ | + .0004” | .800“ - .796 |
9424 | .1882” - .1880“ | + .0006” | .800“ - .796” |
9425 | .1884“ - .1882” | + .0008“ | .800” - .796“ |
9426 | .1886” - .1884“ | + .0010” | .800“ - .796” |
Used for 54-85 Sportster and K Model front crankpin roller bearings | Diameter | Size | |
9150A | .1875“ - .1874” | Standard | .480“ |
9152A | .1877” - .1976“ | + .0002” | .480“ |
9154A | .1879” - .1878“ | + .0004” | .480“ |
9156A | .1881” - .1880“ | + .0006” | .480“ |
9158A | .1883” - .1882“ | + .0008” | .480“ |
9160A | .1885” - .1884“ | + .0010” | .480“ |
9161 | .1873” - .1872“ | - .0002” | .480“ |
Primary / Chain Cover
Year Model | Part Number | Gasket | Notes |
1957-1966 XL/XLH | 34951-57 | 34955-52A | |
1958-1969 XLC/XLCH | 34949-58 | 34952-52 | black |
1964-1969 XLCH | 34949-64 | 34952-52 | chrome |
1967-1970 XLH | 34947-67 | 34955-67 | with needle bearing (9063) |
1970 XLCH | 34948-70 | 34955-67 | |
1971 XLCH | 34948-71 | 34955-67 | cover replaced by 34949-71 in 1972 |
1971-1972 XLH/XLCH 1974-1976 XLH/XLCH 24) | 34949-71 | 34955-67 | with needle bearing (9063), polished |
1973 XLH/XLCH | 34949-73 25) | 34955-67 | with needle bearing (9063), black |
1975-1976 XLH/XLCH | 34949-75 26) | 34955-67 | |
1977 XLH/XLCH | 34949-75 27) | 34955-75 | |
1978-1980 XLH/XLCH | 34956-78 28) 29) 30) | 34955-75 | with two needle bearings (9063 x 2) polished cover from kit (34949-75A) also replacement for 1977 XLH/XLCH |
1979 XLS | 34941-79 | 34955-75 | gray |
1980 XLS | 25424-80 | 34966-80 | cover and gasket are both black |
1981-1984 XLH 1983-1984 XLS | 25430-81 | 34955-75 | polished |
1981-1982 XLS | 25424-81 | 34966-80 | cover and gasket are both black |
1983-1984 XLX | 25433-83 | 34955-75 | aluminum finish |
Gearcase / Cam Cover
Year Model | Cam / Gearcase Cover Part Number | Gasket |
1952-1956 K Models | 25200-52 | 25224-52 25244-52A (1977 part #) |
1954-1956 KH | 25200-52A (1963 part #) | |
1957-1962 XL/XLH/XLCH | 25200-57 25200-63A (1968 part #) |
|
1963-1966 XLH/XLCH 1967-1969 XLCH | 25200-63 25200-63A (1968 part #) |
|
1967-1970 XLH | 25201-67 25201-67A (1969 part #) |
|
1970 XLCH | 25200-70 | |
1971-1972 XLH | 25201-71 | |
1971-1972 XLCH | 25200-71 | |
1973-1974 XLH | 25201-73 black |
|
1973-1974 XLCH | 25200-73 black |
|
1975-1976 XLH | 25211-75 | |
1975-1976 XLCH | 25205-75 | |
1977-1978 XL | 25201-75 | |
1977-1978 XLCH | 25200-75 25201-75 (1978 parts sup) | 25244-52A |
1979- XL | 25201-79 | |
1979- XLCH | 25200-79 | |
1980 XL | 25208-80 black |
|
1980 XLS | 25209-80 polished |
|
E1981 XL | 25227-81 polished |
|
E1981 XLS | 25229-81 black |
|
L1981-1982 XLS | 25209-81 black | 25263-81 '82 part# change |
L1981-E1984 XL 1983-E1984 XLS/XLX | 25208-81 polished |
|
L1984 XLX | 25207-84 alum. finish |
|
L1984 XL/XLS | 25208-84 polished |
|
1985 XLX | 25207-84A black |
|
1985 XL/XLS | 25208-84A polished |
1957-1967 XLs had the solid bar cam cover. 31)
1968-1970 had the finned looking cam cover.
You can interchange the covers if you are not concerned about the look of a stocker for your year bike (better resale trying to stay stock).
Also be aware that some covers had the round cut out for the electric starter XLH that came out in 1967.
You can slap a cover on and wing it, BUT the proper way is to have the cover line reamed when the motor is apart.
(so the cam cover and the right case half are a match in tolerances.
52-78 cover had only one breather port at 6:00. 32)
79-85 had two. One at 6:00 and one at 10:00.
52-76 uses .625” pinion bushing bore.
77-85 uses .562“ pinion bushing bore.
1952-1956 Cam Cover - casting: 25202-52 33) | 1957-1962 Cam Cover - casting: 25202-52A 34) | 1963-1967 Cam Cover - casting: 25202-52A35) |
Cam Cover Bushings
Oil Deflector / Separator Bushing Assembly (57-62): (or spring loaded top hat)
Looking at the brass part, you can see how the spring catches on the inward bent tabs. There are also unbent tabs on the brass. 42)
These, when bent outward just a little, fit into slots on the far side of the steel bushing pressed into cam cover.
Here's how the factory assembled this thing.
They had pre-assembled the brass to the steel before the steel was pressed into the cover.
Then dropped the spring into the cover and pressed the brass/steel assembly into the cover as a unit (and manipulated the spring to sit correctly if needed).
However, it is possible to assemble the unit without removing the steel from the cover. 43)
You can bend the tangs out without having to remove the steel bush with a screwdriver and a hammer to bend the 2 locating tabs out.
Notes:
The tabs must be bent outward enough that the brass stays keyed to the steel at full spring compression.
You don't want the brass hat to 'unkey' when the generator compresses spring.
The brass needs to be able to 'plunge' in and out under the spring pressure once the tags are bent.
If you get too aggressive, you can cause deformations in the brass that allow it to hang up in it's sliding fit to the steel.
These outward bent tangs do 2 things.
- They keep the brass hat and spring captive in the cover upon generator removal.
- More importantly, they key the brass to the steel to prevent the brass from rotating with the generator gear.
The brass is unable to rotate by the tangs keying into the slots.
Inspection:
Check the operation of the oil separator bushing assembly.
The spring should have free action and be fully extended in the gearcase cover.
Crankcase Oil Strainer
- If you've split the cases and the screen is in good shape, you don't have to take it out. Hit it with some compressed air and see if it needs replacing. 49)
50) 51)
The strainer is held in place by this pin. It is staked into place with the two horizontal lines radiating from the it. To remove strainer, you must first remove the pin. Tear the screen from the strainer and place pliers on the pin inside (the now destroyed strainer) and wiggle the pin out. Strainers and strainer gaskets are available for replacement. 52)