What is the logic behind using ATF (hydraulic fluid) in the transfer case rather than a quality light weight oil (lubricant) be it synthetic or other wise ?

Look forward to your comments.

Brett

 

I'm sure you could use hydraulic fluid or even 5w30 but ATF is cheap. There is no need to use the Chrysler +3 or +4 ATF, just use good ol' cheap to buy anywhere Dexron III

 

I don't know the logic either, but have changed the T-case fluid out twice now, and both times it's extremely dirty, the used ATF being a very dark, grey color. Lots of visible wear particles in it.

I have been using Mobil 1 ATF, but have just orderd a product from Speciality Formulations that's basically ATF with five times more anit-wear additives in it. This full synthetic fluid is designed for use in gearboxes that require an ATF, but offers much better wear protection. This stuff is a little over $7 a quart, which is about the same price as Mobil 1 ATF. I happened to stumble across it, so thought I'd give it a try in the T-case.

 

In 70,000 miles I have changed the transfer case ATF twice and both times wondered why I even changed it the oil was so clean and new looking. Makes me think you might have something else going on inside your transfer case.

 

I agree with BlueBull!

I've changed mine once at 30K and it still looked clean and new. It didn't even smell bad. But I changed the fluid reguardless... save than sorry!

 

Same here, always clean. Makes me wonder why I bother changing it.

 

I bought a '99 with 170,000 miles, it was hit on bottom and transfer case cracked open in half.
All the components are still there and they look almost brand new, chain is immaculate.
Makes me wonder about the oil inside...

 

Well I have 190 K Mi. on mine . Mostly all hwy miles. I removed the transfer case to replace the 5th gear nut ( I have a 5 speed). I spun the input shaft on the trans case and wasnt really comfortable with the feel of the bearing(s). I ended up replacing a few bearings because of what I felt was excessive slop. I also replaced all the seals. The bearing wear in that heavy duty trans. case caused me to ask myself if it wouldnt be better to use a REAL lubricant . I was tempted to use a 30 wt. or lighter synthetic .
Would that present any problems ? Would this oil be compatible with the seals ?
Im kind of liking the idea of one of the posts who mentioned using the upgraded atf. Redline has a similar product.

Thanks ,

Brett..............

 

mine was dirty once and the tranfer case had a bearing out of only made noise under heavy work its still very weird to me

 

There are a couple compelling reasons to use ATF instead of other oils in these t-cases. Since these chain driven cases don't have any large gears (just one planetary) that rely on the sling and cling method of lubrication, there is no need to have a heavy weight oil.....in fact, the heavier oils can make things worse since there is a pump system that lubes all the internals.....the heavier oils will tax the pump and drastically slow down the flow rate. ATF also has a high content of detergents in it that do a very good job keeping the t-case clean.

As we have seen and experienced, ATF does absolutely nothing to hinder the longevity of these t-cases.