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B1 lower leaking lube around input shaft

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B1 lower leaking lube around input shaft

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Old 08-01-2019, 07:19 AM
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If it were mine I would take the lower completely apart and start over ,first check that the lower pinion gear is shimmed to the correct height,,be sure the correct bearings and races are installed on the vertical shaft,,,install the correct shims to get the correct rolling torque on the vertical shaft, when all these things are set correctly the spacer and o-ring should be at the correct height to seal the oil.,,
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Old 08-04-2019, 05:54 AM
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Allittle Ultra Black will seal you right up.
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Old 08-04-2019, 09:47 AM
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Originally Posted by 253 View Post
If it were mine I would take the lower completely apart and start over ,first check that the lower pinion gear is shimmed to the correct height,,be sure the correct bearings and races are installed on the vertical shaft,,,install the correct shims to get the correct rolling torque on the vertical shaft, when all these things are set correctly the spacer and o-ring should be at the correct height to seal the oil.,,
What he said. When the lower is assembled correctly the top of the retainer is a few thousandths above the lower housing. This represents the preload applied to the upper 2 bearings on the shaft.

First the pinion height is set by the shims under the lower cup then the preload is set by the shims above the tab washer. When the upper & lower are assembled the retainer is clamped flush. The o ring probably adds a little bit of preload but it is really only there to seal.

If the top of the retainer is exactly flush or below the surface for sure there is something wrong.
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Old 09-06-2019, 04:51 PM
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Update:
So a huge THANKS to Jeff Harris of Harris Performance!!! He knows tech spec details and can talk specifically to the design.
Preloading a bearing through an oring made no sense to me but the plate crushes between the upper and lower to set/hold the shim preload. I could follow that. #17 is called a spacer in the diagram but that is more functionally a centering plate for the lower input shaft and it is part of the shim buildup to set preload. So the bottom line on the plate/spacer is 1/2 to .001 above the deck of the lower. Somehow my plate was down .007. Just out of nowhere this drive starts leaking and this is why. Why it dropped .007 is still a mystery but it caused a leak.
I have another drive and the plate/spacers are different thicknesses and the shim stacks were different so between the two I was able to set my spacer to spec, between 1/2 and .001. We ran four days in Allatoona, slept on the boat and it has set where the sun would shine on the drives and build pressure to the point of a leak and still, no leak. The drive is quiet, no noise and nothing has changed but the leak is gone.
Happy Boating
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