ATF in the FJ62 T-case? What's the consensus on this? (1 Viewer)

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studawg

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yay or nay?

I read somewhere that Toyota changed their recommended procedure on this somewhere around '90. Is that true?
 
What if the ATF is GL4 compatible?
 
I have read but cannot confirm that most high quality Atf well pass gl4 tests, so far only one I can find publish it on the bottle is redline. ..

I think gear oil is best, but if it risks blowing the trans due to the notorious input seal... maybe not.

I think other 4x4 vehicles spec atf in the t case... just saying.
 
What if the ATF is GL4 compatible?

That I'm not sure. I don't know if there were GL-4 rated ATF fluids available when the split case was designed.

Give it a shot! Worst case scenario is that your split case blows up and we use you as an example of what fluid to not put in the split case :lol:



Millions of miles have been put on split cases running gear oil. How many when the split case is filled only with ATF? Just saying. :hillbilly: Not all transfer cases are alike.
 
Last time I changed the tcase oil I found some ATF in it so after doing a Rodney flush on the trans with the expensive amsoil I decided to put ATF in the tcase to prevent contamination. Long story short my tcase developed a high pitch noise at high speeds after a few thousand miles.
I have since gone back to gear oil but the damage is done.
Now I need to rebuild the split case
 
I don't think trust washers on your t-case ( or any other component for that matter ) was designed to work with ATF .. non educated guess, lubricity capabilities should be quite different .?
 
Last time I changed the tcase oil I found some ATF in it so after doing a Rodney flush on the trans with the expensive amsoil I decided to put ATF in the tcase to prevent contamination. Long story short my tcase developed a high pitch noise at high speeds after a few thousand miles.
I have since gone back to gear oil but the damage is done.
Now I need to rebuild the split case


Hmmm, sounds pretty cut and dry, but I have to ask, whats the "long story"? Was it Amsoil ATF? Was that stuff GL4 compatible? How many miles on the tcase?
 
Hmmm, sounds pretty cut and dry, but I have to ask, whats the "long story"? Was it Amsoil ATF? Was that stuff GL4 compatible? How many miles on the tcase?

I'll have to give you the "long story" over beers. No I ran out of the amsoil with the flush. Just some regular old ATF. 238k miles on the truck assuming the tcase has never been done.
 
Just out of curiosity, why would you want to use ATF?
 
Just out of curiosity, why would you want to use ATF?
Well, heres how it went. I noticed some gear oil leaking onto the ground, under the t case. Around the same time, I noticed a slight whine coming from the vehicle at speed. Checked trans fluid and its way over. I decided Im going to drain both the tranny and t case and put in fresh fluid/oil. If my seal has gone bad, I don't want gear oil going into the tranny. I drained both today and the trans fluid was a little brownish and looked like it had gear oil in it. My thinking is if there is a fluid that will satisfy the requirements of both units, why not run it? As long as I keep an eye on the fluid levels in both, there would be no need to replace that seal.
 
Same here, previous owner ran, and I still run the Redline oil in the tcase because of the oil migration issue with the Marks adapter. T-Case is very noisy...
 
I ran ATF in mine for a couple weeks once while I waited on the transfer rebuild kit and a McNamara gear. Same deal, the seal was gone and I wanted to make sure I didn't get gear oil in the auto. The transfer was noticeably louder and the clunk harsher while the ATF was in.
 
Iuse 75w90 API4 synthetic oil in my HJ 61 gear box & transfer case.I would definitely recommend this stuff if you're looking for smoother shifting in your manual tranny.
Dont use API 5
 
I have experience with ATF oil in my Landrover 110 LT77 gearbox.
Landrover used to spec ATF as there is a plastic oil pump in the gearbox, if you used normal gear oil it was too thick and the pump would break!
But it turns out that ATF didn't really work too well, so they changed their mind and now spec a thin synthetic gear oil.
I wouldn't try ATF in a Land cruiser box.
 
Here's the thing, tho- look at what's in an auto transmission.
Lots of hypoid gears, high gear tooth contact pressures, lots
of heat, and lots of thrust washers with potentially a lot of force
acting on them.

Will it be ideal? Heck, no.
But it should be loads better than
getting gear oil into an autobox, which
CAN be murdered by GL4.

I wouldn't do it unless I had the leak,.
but then I would.

Actually, I lied- I'd swap the whole mess
for a manual gearbox.

Problem solved.

heh

t
 
Any reason you chose this one instead of the D4 or D6? I am under the impression you are running it in both your trans and transfer case?

Because it was the closest match to Gear oil. Higher viscosity and higher temp range.

D4 in the trans.
 
Last edited:
Because it was the closest match to Gear oil. Higher viscosity and higher temp range.

D4 in the trans.

The point here was to figure out if there is one fluid to run in both the tranny and tcase, that will lubricate both adequately, so if the seal between the two goes bad, no damage will be done to either unit.
 

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