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techtalk:ih:oil03h [2021/11/07 05:45] hippysmack [Gearshaft resistance] |
techtalk:ih:oil03h [2021/11/07 08:01] hippysmack [Gearshaft resistance] |
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| Once the oil pump is installed and tightened up, the gears will be hard to turn by hand. \\ | Once the oil pump is installed and tightened up, the gears will be hard to turn by hand. \\ | ||
| - | This is normal and because of the spring washer between the upper and lower plates. \\ | + | This is normal and because of the spring washer between the upper and lower separator plates. \\ |
| + | 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)) \\ | ||
| 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); \\ | 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); \\ | ||
| 1977-1990 oil pumps have to be turned with 2 fingers... and some guff. It will be difficult (but doable) to turn. \\ | 1977-1990 oil pumps have to be turned with 2 fingers... and some guff. It will be difficult (but doable) to turn. \\ | ||
| 1991-up oil pumps have no spring washer, only one separator plate and can be spun using 1 finger to roll the gearshaft around. \\ | 1991-up oil pumps have no spring washer, only one separator plate and can be spun using 1 finger to roll the gearshaft around. \\ | ||
| - | |||
| If you were to remove the spring between the plates on 77-90 pumps, the gearshaft would be easily turned with one finger. \\ | 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. \\ | 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. \\ | The pump housing and cover on these are both designed / machined to include that spring washer. \\ | ||
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| It is solely the spring that makes the resistance on 77-90 pumps. \\ | 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 ===== | ===== Smoke Testing the Oil Supply ===== | ||
