Differences

This shows you the differences between two versions of the page.

--- techtalk:ih:oil03h [2021/11/06 17:27]
hippysmack [Installing Oil Pump]
+++ techtalk:ih:oil03h [2021/11/07 08:01]
hippysmack [Gearshaft resistance]
@@ Line 29: / Line 29: @@
 ====== Installing the Oil Pump ======
+===== Prior to installing the pump =====
+It is assumed that before installing the oil pump, it has been opened up, inspected, measured for wear, lubed and reassembled. \\
+This is normal maintenance for a gerotor type oil pump and should be done from time to time especially if you have no personal history with the oil pump. \\
+If you just bought the bike or oil pump, never assume this has already been done by the P.O. or whoever you bought it from. \\
+If the pump has been in service for "years without problems", it's still a very good idea to pull the pump apart for inspection when you can. \\
+  * Make sure the internals match the pump housing and cover before installing a gerotor oil pump on an Ironhead.
+    * There were basically 2 different style oil pumps from 1977 to 1985; (1977-E1983 style and L1983-1985 style). \\ There were many part number changes for pump assemblies which mainly amounted to hose fitting changes although there were housing changes also. \\ But a big no-no is mixing internals of the two different styles of pumps without the knowledge of what the factory changes were.
+    * The part numbers are not cast or stamped into the oil pump or it's internals so you cannot match parts catalog numbers to a used oil pump. \\
+    * Rule of thumb (from the MoCo) on mixing gerotor oil pump internals: \\ Any 1977-1985 oil pump can be mated to 1977-1985 cases as a unit. Mixing internal parts gets a little tricky though. \\ 77-E83 gerotors can be used in L83-up pumps. L83-up gerotors can only be used in L83-up style pumps. \\ [[techtalk:ih:oil03a#late_1983_oil_pump_assembly_design_modification|Click Here]] to read more specific information on the L83 oil pump changes. \\ There are also pics of the chamfered and non chamfered gerotors on that page if you scroll the page. \\
+  * There were 2 different outer separator plates (next to the feed gerotors) used from 77-85 with different IDs. \\ Each has it's own type gearshaft seal that must be used with it. \\ Each plate will fit any 77-85 oil pump as a set with it's specific seal (can't mix and match gearshaft seals).
+  * One problem with assembling an IH gerotor pump is the roll pin in the oil pump housing. \\ The lower (outer) spacer plate has a slot cut into it that goes around that pin in the housing. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5798817)) \\ The spring pressure pushes this connection outward and with a loose cover, the outer plate will spin over the top of the pin. \\ If the plate rides on the end of the pin when the cover is installed then tightened down, this will lock the pump to the point of damage with the motor running. \\ Best to assemble the pump with duct tape until you get it mounted to keep the spacer from moving. \\ Else the pump can lock up once the bolts are in due to the washer not being sunk into the housing properly.
+===== Gearshaft resistance =====
 Once the oil pump is installed and tightened up, the gears will be hard to turn by hand. \\
-This is because of the spring between the upper and lower plates. \\
+This is normal and because of the spring washer between the upper and lower separator plates. \\
-In fact, you can use a couple nuts and bolts to clamp the cover to the housing just holding the pump in hand (all internals installed). \\
+The resistance felt at the driveshaft gear is only generated from pressure against the feed gerotors. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2071153&page=12)) \\
-And it will be difficult (but doable) to turn. \\
+In fact, with the pump removed from the engine, assembled with all internals (a couple nuts and bolts to clamp the cover to the housing); \\
-If you were to remove the spring between the plates, the gearshaft would be easily turned with one finger. \\
+-1990 oil pumps have to be turned with 2 fingers... and some guff. It will be difficult (but doable) to turn. \\
-But you can't run these type pumps without the spring between the plates. \\
+-up oil pumps have no spring washer, only one separator plate and can be spun using 1 finger to roll the gearshaft around. \\
-The pump housing and cover are both machined to include that spring washer.. \\
+If you were to remove the spring between the plates on 77-90 pumps, the gearshaft would be easily turned with one finger. \\
+But you can't run 77-90 oil pumps without the spring between the plates. \\
+The pump housing and cover on these are both designed / machined to include that spring washer. \\
+It is solely the spring that makes the resistance on 77-90 pumps. \\
+The pump housing has two separate bores for feed and return gerotors with the return set being smaller in diameter. \\
+With the return side on top, the divide between the two housing bores creates a "shelf" where the small bore stops and the larger feed side bore begins. \\
+The inner separator plate sits against that "shelf" between the bores, then the spring washer and outer separator plate go on. \\
+With this design, the return gerotors are shielded from spring pressure since they are above that divide between the bores. \\
+During operation, the inner plate is nestled against the "shelf" (not touching the return gerotors). \\
+The feed gerotors are placed into and protrude out from the cover and they end up taking the pressure from the spring washer. \\
+The feed gerotors butt into the outer separator plate, pushing and compressing the spring washer against the inner separator plate / bore divide in the housing. \\
 ===== Smoke Testing the Oil Supply =====
 This is not required but doesn't sound like a bad idea to test the oil pump and supply feed passages on a new engine or pump build. \\

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