Differential Failures

[E. Roy Wendell IV]

> The differentials fail when using different diameter tires because  
> of lack of
> proper lubrication.
> If you ever taken apart a normal differential, you can see that  
> those side- and
> pinion-gear bearings are not designed for continuous rotation.  
> Those are just a
> pin and a hole with a sliding fit, no rolling elements, no bearing  
> inserts, no
> pressure lubrication, etc.
> Of course it could have been engineered properly, exept it would  
> have cost more
> money to produce.
>
> Peter

Peter hit the nail directly on the head. The spider gears aren't  
meant to rotate for extended periods of time or very fast. They  
aren't pressure lubricated and there are no bearings of any kind  
where they ride on the shaft.

If you want to see what kind of failure results from continued motion  
of the spider gears relative to the shaft check out this link:
  http://www.racepa.com/forums/index.php?showtopic=4104&st=0
Note how the spider gears wore 2/3rds of the way through the shaft  
before it finally snapped.

Roy Wendell
erwendell at mac.com
Too many type 44 tq
A pair of MR2s