I looked at a junk yard tranny. It had ATF in the front differnetial. I told the guy he shouldn't be selling that tranny do anyone. He said that it wouldn't matter. Personally, I think there is a huge difference between ATF and 80W90. Wouldn't it damage the gears?

Yes, it could damage something if the concentration gets high enough.

 

Conversely, that means 80W90 is probably mixing in the ATF in the transmission, which would be worse

 

The diff needs to be separated from the tranny, and the seal between them replaced.

ACutally, i think someone just added ATF to diff because they didn't know one dip stick from the other...what a dip stick!

thas what i would think. there is a legacy in a junkyard here i will see if i can get it should you not find one, i will be coming to the iowa meet i could bring it and put it in for you.

MilesFox....will have you hold off on the tranny for right now. Still have a few leads here I'm looking into. Thanks.

Be careful of your assumptions. Like subyluvr2212 said, it is likely that the seal between the trans and diff sections failed. This is VERY common on the automatics.

haha.. my autotragic from the wagon was damnear pure atf in the front diff.. i mean it was red on the dipstick...

 

oddly enough i put thousands of miles on it that way but when i finally killed the tranny there was a smidge.. ok.. 1/8 or more inch of in and out play on the output stubs for the diff... i keep meaning to pull it apart and see just how worn down it is

but then again.. it was a 230k mile tranny.. so it actually held up well i would say

 

also not sure about newer sube's but alot of newer transfercases and yes <if i remember right> even a few differentials actually use atf instead of gear oil

It used to be considered a speed secret. I run ATF in my BMW 5 speed manual tranny and it is stock.

I like something with more scuff resistance in the rear end, but I have seen ATF run for years in a drag car.