Re: KPack's 1954 Panama

Posted by DavidPackard On 2021/4/9 14:46:26

Kevin:

I’m not really sure how to evaluate GL-5 being introduced near the outer diameter of the race. On one hand the coefficient of friction would be reduced and the bearing would/may rotate with a lower level of torque . . . torque coming from bearing drag. Countering that would be the general tendency of the oil preventing marking/galling/scoring of the parts. You may really have nothing more than an exhibit for Ross’ no fun with used cars.

Unless the bearing fit wildly in excess of the 0.0015 limit I would believe the seal damage is not related to the loose bearing fit. It is an interesting situation in that all lip seals need some initial lubrication, and some sustaining lubrication to avoid rapid wear. Given that GM was using a ball bearing in the same location, and this bearing was sealed on the outboard side, and unsealed facing the differential. That design clearly used the differential oil to lubricate the ball bearing, therefore the rear axle seal on the Packard is likely lubricated by the differential oil, not the grease applied to the bearing.

Now let’s talk about seal life and bearing clearance that involves the shims. As the clearance is increased additional deflection will occur at the seal, and that deflection is with the axle deflected upward. If the seal wear appears near 12 o’clock that would be an indication the bearing clearance at one time was on the high side.

I’ll take another walk through the Packard service information looking for advice on initial lubrication of the inboard seal. I know there is guidance on not applying ‘extra’ grease on the shaft or housing. From that I’ve drawn the conclusion that the interface between the housing and outer bearing race should not be lubricated . . . at least with grease. I normally wipe the surfaces with grease, and then wipe them clean, which is more of a rust preventative step than lubrication. If I can’t find anything in the Packard stuff I’ll craft a sentence or two on the in the supplement.

I would wipe the entire circumference of the seal with GL-5 just before the axle is installed, and apply some on the axle shaft from the spline to the point where the seal rides . . . not beyond.

While you’re checking the fit of the bearing in the bore try several location, meaning different ‘clocking’ positions, and if the feeler gauge check is conducted try a few different locations . . . . just trying to figure out if the housing bore is round or egg shaped.

dp