My 10 bolt has well worn in gears, soon to have a torsen diff.
I know The torsen dosen't care if it has gear oil or atf (says so in owners manual thing), ring and pinion gears just need to be wetted with (any) oil, bearings and seals don't care eather.
Would it hurt any thing if I ran atf in my 10 bolt with torsen?

 

Er, I'm thinking that you would want heavy oil for your rear. If it's a daily driver, the lighter ATF won't protect against 'gear shock' as the gears mesh together, worn or not. Some Super Stock guys run ATF in their rear becasue it doesn't give the amount of drag normal gear oil would and they're towing the car to the track for 1/4 mile runs only. But, given a choice between NO oil and ATF, I know what I would pick.

Anyone else? *shrug*

 

I know FWD's autos and manual have a ring and pinion a lot like what we have. There ring and pinions have atf around them.
The draw back and limit for them is they have to have a diff that can work in atf.
The stock 10-bolt diff needs gear oil, but I have a diff that dosent care what its in.
Parts of a 10 bolt
pinion bearings and seal, should be good with atf.
ring and pinion gears, sould be good with aft between them.
The zexal-torsen, I know is goon in atf.
diff bearings should be fine in atf.
the axel bearings and seals should be fine.
Are any of these parts or are there any other parts that aft would be bad for in my other wise stock 10 bolt?
I want to run aft if I can because I want to run realy fast down the interstate and less drag would be great, thats what I want.

 

I think the safest bet all around would be to go with a synthetic rear gear oil. I wouldn't trust ATF either... don't forget that you're not only wetting the posi unit, but you're also wetting the axleshaft bearings, too.