Topic: ATF Fluid in gear Tcase??

[surfindave]

Hi guys just building my marlin crawler and have the auto guys have had oil issues with the coupler so i was wondering if auto tranny fluid would be ok to use in the Dual case setup ?
What would happen if ATF fluid mixd with gear oil?
What would happen if the gear oil got into the Auto???
Thanks Dave

[mr4x42u]

Thats a good question,,I think its not very likly to get 80/90 in the trans,,the pressure in the auto I'm sure is greater then in the t-case wich would keep out the 80/90..On the flip i doubt it would hurt anything having atf in there..Alot of cases run atf,,all mostly chain cases but i don't know what damage if any would happen..My guess is you would just change your fluid a bit more often..

[surfindave [OP]]

Hey Thanks
I have been doin some research over here and found some ppl are running mobil 1 synthetic in there autos for race type 4x4n applications i thought this would be a no go but apperantly it is shite hot???

[Huhwhye]

The ATF in the T-case is less of a concern.  I'd be more worried about gear oil in the Auto trans.

There are a bunch of manual transmissions in the world that use ATF for lubrication.  It's thinner, produces better performance and mileage.  So I would think that a little ATF getting in the t-case would not be a huge problem.  But if you want to run ATF as a primary lube for the T-case I'll do some research on that and get back to you.

[Huhwhye]

OK I was wrong.  I asked a guy who blends and sells specialty oils for a living.  And he said no ATF will protect/properly lubricate a T-case that calls for a GL5.  You will have accelerated wear.  But some kind of lubricant is better than running it dry.  If you have a chain case that uses ATF you may be fine and if it leaks between the 2 probably not a problem.

But if a gear case would leak oil into a trans I'd image there could be a possibility with the added gear reduction that stress on the outputs and its seal may cause some leakage after many miles of use.  But I don't think its a huge issue.

As far as contamination.  Its one of those things where it will work but the ATF will likely not last as long as it would if uncontaiminated.  And we could speculate as to what would happen to the trans clutches if the gear oils additive pack has friction modifiers in it.  But any guess is as good as mine there.