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techtalk:ih:oil03p [2021/11/11 21:07] hippysmack [Inspect the oil pump cover and body] |
techtalk:ih:oil03p [2021/11/11 21:26] hippysmack [Inspect both gerotor sets] |
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| * The gerotors are much taller than the pin thickness. | * The gerotors are much taller than the pin thickness. | ||
| * So the height of the slot allows a fudge factor on quick throttle blips and the gerotors won't be affected. \\ The gearshaft will rise some on higher throttle and there is built in "up and down" clearance in the pump to allow this. \\ | * So the height of the slot allows a fudge factor on quick throttle blips and the gerotors won't be affected. \\ The gearshaft will rise some on higher throttle and there is built in "up and down" clearance in the pump to allow this. \\ | ||
| - | * The pins are not pressed into the gearshaft and the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ You can buy a handful of new pins only to find they are all different dims as well. \\ If you find real slop in the pin fit to the pins, either replace the pins and/or the gearshaft. \\ Do not buy hardened pins as that will defeat the purpose of the "shear pin" design. If the pins only protrude slightly into the gerotor slots, use longer pins. \\ | + | * The pins are not pressed into the gearshaft and the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ You can buy a handful of new pins only to find they are all different dims as well. \\ If you find real slop in the pin fit to the gearshaft, either replace the pins and/or the gearshaft. \\ Do not buy hardened pins as that will defeat the purpose of the "shear pin" design. If the pins only protrude slightly into the gerotor slots, use longer pins. \\ |
| The pics below are used parts but show the pin locations and how they look installed with a gerotor on the shaft. \\ | The pics below are used parts but show the pin locations and how they look installed with a gerotor on the shaft. \\ | ||
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| **Check inner to outer gerotor clearance on each gerotor set**. \\ | **Check inner to outer gerotor clearance on each gerotor set**. \\ | ||
| Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\ | Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\ | ||
| + | This clearance has a direct relationship to oil pump flow and oil pressure. \\ | ||
| + | The wider the clearance the more the gerotors lose their ability to hold enough pressure to the outlet cavity. \\ | ||
| + | They also the ability to transfer oil from the feed cavity back to the inlet cavity and recirculate oil within the oil pump. \\ | ||
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| * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set. | * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set. | ||
| {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
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