Transfer Case -- ATF vs Gear Oil

[Clickty Clack]

Question:

Has anyone tried gear oil in your transfer case?



My Issue:

I have recently changed mine. I went with Amsoil ATF. Since then, I have noticed a oil film on my under carriage and exhaust around the rear seal of the transfer case. There are no drips on my drive way. I had the same issue with a Jeep Wrangler (15K total miles) immediately after a change to the Amsoil. Is the Amsoil ATF (AFT in general) to thin for the seals to hold back? Would not gear oil work perfectly well is this application? It's just gears and chains. Has anyone tried this? If so, what weight?

 

[PC12Driver]

New Process says you need ATF. Gear oil would be waaaay to thick. Aside from the extra drag (windage), I don't think it would be to great for the synchro's (for the 2-4 hi shift-on-the-fly). Plus, the gear oil may not have the slinging properties of the ATF to be able to get to everywhere it needs to be in the case.



FWIW, I've had that film around the output of my xfer case since the truck was fairly new, with the factory fill and with Redline synthetic. The slip yoke design is bound to throw some fluid out as the yoke moves in and out of the case. If it's not dripping you still have a good seal.

 

[Heavyweight]

I use Amsoil transmission fluid in the Transfer Case, all 2. 5 quarts without a drop comming out. I drained the factory ATF+4 after 2,000 miles. There was only 2 quarts in there from Dodge. The Mexican plant must be on the Peso system?

 

[MickeyMiller]

I just did my second change of t-case fluid, first at 15K... replaced with Chrysler +4 ATF (as specified). This change was at 43K... drained fluid was clean and red, with just a sight wiff of burnt odor. This time I used Redline C+ ATF... 2. 5 quarts.

 

[JCulp]

is that the same with the 5 sp transmission . to use atf

 

[Sled Puller]

The 5 speed takes aGL-4 lubricant.



Do a search, I posted pics of my transfer case a few months back on Amsoil ATF.



The seal does wear a groove in the metal on the shaft, it was probably starting to seep, and then leaked faster with Amsoil.

 

[justinp20012500]

The T case has pump that pumps the ATF.



The pump will not pump gear oil.

 

[Luke Warmwater]

I changed mine out this weekend and for some reason can't get more than 2 quarts back in even pointed downhill a little. I thought they held 3?



It was explained that not all the diesels come with the HD but even the std 241 should hold 2. 5 or so?

 

[Huff N Puff]

I agree with justin. The transfere case has an oil pump with a screen. Its too fine for gear oil to flow thru.

 

[CumminsPower98]

I have been running Amsoil Series 3000 HDD 5W30 for probably over 80k miles with no problems that I know of and I think some others are as well. Gear oil is for sure too thick. I hope I'm not killing this thing anyway. I have never been inside this case so don't really know how it lubes.

 

[B KIRK]

Been running Amsoil 75-90 gear oil in my 94 since 95. I just put a new DTT transmission in several months ago. Transfer case was sitting on the work bench. 90K miles on it with the gear lube. Thought I might as well take a look inside while it was out, to at least clean the magnet. Well, that was a waste of time. Wasn't enough particles on the magnet to clean off. Put it back together, and filled it back up with Amsoil 75-90 again.



Brad

 

[keimmmo]

I have used 5W-30 synthetic motor oil in my case for nearly 100k. I tow heavy and use the low range a lot. The factory fill was burnt at 15k. I change the synthetic motor oil every 15-20k and it looks like new every time.



Steve