My '86 T/A has about 80,000 on the clock, and I am getting ready to do an extensive suspension/driveline upgrade.
Part of this will include swapping gears up to 3.23 or 3.42. Will I need to look in to replacing the Posi unit? How long does a Posi last, anyhow?
If I need to replace the Posi, that means new axles, bearings, (c-clip eliminators) and the like, right?

 

It all depends. Is the posi that is in it the original saginaw? If it is you are already living on borrowed time.

My brother-in-law had a friend that worked for GM in the customer complaint dept and said they had calls coming in daily about the limitied slip difs giving out (his let go at about 7k miles). My governor exploded at 35k miles and made a mess of the rearend (acted like a full spool rearend), When GM replaced it they used an Auburn unit. Works good, lasts long time.

~M~