<VV> RE: Differential rebuild

[BobHelt at aol.com]

In a message dated 7/21/05 10:20:56 AM US Mountain Standard Time, 
Corvair at fnader.com writes:

> But my question is... why would it NOT be "desirable or preferable"? Other 
> than the expense, what do you see as the downsides?
> 
> Bill Elliott
> 

Hi Bill,
Well, again, this is just my opinion, but here it is.

The factory produced some 1.7 mil Corvairs without the 4 spider setup. These 
were used in many applications and never required it. Sure, some had spider 
gear failure, but the number of failures for NORMAL driving was miniscule. 
Therefore experience tells us that there is no need for this in normal driving.

Second is the cost...some $400. That's a bunch. And what is to be gained on a 
daily driver? What is the likelihood of a spider failure on a two gear setup 
compared to a 4 gear setup of equal quality? In my opinion, it's close to 
zero.

If he has worn, cracked or defective spider gears in the 2 gear setup, then 
of course replace these to get reliability. But what will 4 gears add? More 
reliability, OR LESS?
Two more gears spread the load for more even wear, but two more gears (and 
added parts) also add complexity and MAY (MAY!) lower reliability for long term 
normal driving. An old rocket engineer's thoughts! Complexity lowers 
reliability.

Lastly is the effort and risk in installing a 4 gear setup. No problem for 
the experienced.... But if he has never done this before there's risk in getting 
the preloads set right, and risk in setting the mesh pattern correctly. Risk 
too in some other kind of mistake. Risks are acceptable if the rewards are 
GREAT too. But what will be the great reward for having a 4 gear setup installed? 
What can he expect for this added cost, time and RISK?

Regards,
Bob Helt