Corolla diff fluid

[itburnz]

Ok, I got a question regarding the diff that is bolted onto my 3-sp auto transmission; it's an '86 Corolla. What fluid does it take? The Haynes manual says Dexron ATF, but when I had a leak and brought it to a shop (it always happens on trips when you don't bring jackstands along) they filled it with gear oil. I have been running on that for about 4k miles now. Would there be a reason to change it to Dexron?

BTW there's a lot of backlash in the diff and I get a loud thud when going into reverse after stopping; it has been doing this all along. I thought about driving it until the diff dies unless someone knows where I could get a replacement that doesn't cost an arm and a leg and doesn't require me to dismantle a junk-car first.

Thanks!

[84Hachi]

The owners manual calls for 80W-90 Hypoid gear oil. But any 80W-90 Gear oil will work.

[Brian]

ae86 RWD takes GL5 75w90 or 80w90

ae82 FWD takes GL4 (ATF) but GL5 gear oil won't hurt a thing, other than a slight change in fuel economy.