Hey guys, I'm looking at a '86 iroc to buy, and I'm wondering what this car comes with as far as trans [700r4] and how to check if it's got posi without jacking it up. I know it is a 305 tpi car but haven't actually looked at the car yet. Thanks for any info.

 

The following FAQ, assuming the car isn't equipped with a 9-bolt, will provide some info about about the rear (if the car is an auto, it's a 700R4):

https://www.thirdgen.org/forums/tran...-10-bolts.html

Without popping the diff cover, however, determining what's really there after 20+ years is difficult.

JamesC

 

RPO codes in the glove box and look for a tag bolted to the diff cover that says that it is a pos or limited slip.

 

After 23 years, donn't assume the original RPO codes are correct anymore.

Tount the gear ratio & check for posi action (assuming it isn't dead or blown), just jack the tires up off the ground & rotate them by hand. Count the # of turns of the tires vs the # of turns of the pinion yoke & you can find the gear ration. All without ever opening the rear end & the oil in it dumping out on you, then having to refill it afterwards.

 

All right, so stock with 700r4 and either way on diff, I'll just have to insp. it. Thanks for the tips.