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Pinion shaft

Hi all,

This past weekend I replaced the rear axle bearings in my '91 LX. According to the manuals, part of the procedure involves removing the pinion shaft from the carrier assembly. Well, the whole procedure went well with the exception of one problem: when I inspected the pinion shaft, there was some damage. There was evidence of extreme heat and metal was actually moved and scored on the shaft. There are two parallel flat spots on each end of the shaft where the spider (?) gears run on the shaft. Here there was a bit of scoring barely detectable with the fingernail and some of the metal was "folded" over on to the flat spots of the shaft. Is this a serious cause for concern or is this normal wear? How does this happen? Is it due to some serious abuse of the car? Any thoughts would be appreciated.

/Tim.

Reply to
5point0
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The wear you saw is "*normal*" and usually a sign of wheel spin. In normal operation (straight ahead driving) the spider pinions don't rotate on the differential pin. If we honk on it and one wheel spins, there is a great deal of force applied to the bore of the pinions and the surface of the pin. If it were mine, I would have likely changed the pin (BTW, I never re-use the retaining bolt) and possibly the pinions, as well.

That there is some wear is no biggie but this will affect the strength of the pin adversely. A lot depends on how you drive..... now that the bearing surface is no longer smooth, we can expect a breakdown of the oil film betwixt gear and pin - again, no biggie if we don't honk on it.

Not knowing how you drive or if testosterone gets in the way on occasion, I can only insert the sound of rolling dice......

appreciated.

Reply to
Jim Warman

Thanks Jim. I ordered a new pinion shaft and will be installing it tomorrow night. Hopefully everything will be okay. As for my driving habits, I don't do a lot of tire spinning but I do like to drive fast :).

Reply to
5point0

Put it back in and drive it. As you stated the damage was barely detectable. What lead you to the conclusion of high heat? Were the parts bluish? Oil burned? If as you say there was high heat to cause that damage then you would have had other clues than the minor details you described.

5po>Hi all,
Reply to
C5_Mechanic

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