Engine/Transmission (1994 - 1998) Transfer Case Oil

[Jschafer]

I have found posts on the oil for the differential and using synthetic oil but have not seen anything on the transfer case. Is anybody changed over to full synthetic in the T-case why or why not.

 

[Cummins4Life]

Yes synthetic ATF works fine in your transfercase. I've always used whatever I have in the transmission to keep things simple though.

 

[Joseph Donnelly]

I got Chevron Dexron 3 by the case at Costco and changed every 15,000 miles. Transfer case was still fine after 133,000 when I sold my 1997. It took about 3 qt.

 

[kentdiesel]

I use Mobil 1 Synthetic ATF in the transfer case.

Kent

 

[Forrest]

Are the fill & drain on the transfer case on the rear of it?





thanks

 

[jrobinson2]

The drain and fill are the two Allen head plugs facing back in the rear case half.



Jared

 

[Forrest]

Sweeeet ... saw them Jared ... thanks. Hopefully they are the same size as the fill plug on the transmission. I'll find out tomorrow.

 

[Joseph Donnelly]

I think the plugs were all 22 mm metric pipe, but the heads were Torx and a large hex at the perimeter up to about 1995-6. After that they went to 10mm Allen, I think. The NV4500 fill plug is 3/4 pipe.

 

[Jschafer]

In the real world does the trans oil on an automatic ever mix with the transfer case?

I have heard that the synthetic oil is to slippery for the Trans.

 

[jrobinson2]

Sweeeet ... saw them Jared ... thanks. Hopefully they are the same size as the fill plug on the transmission. I'll find out tomorrow.

They are different on my '99, I think the trans takes an SAE allen and the t-case needs a metric allen...



Jared

 

[KB0OU]

I run Mobile One Synthetic Motor oil in my transfere case. Was talking to an engineer once and he said it was best to run. Not recommended to run the thicker stuff unless you are in really hot climates. 356K miles and all is still well in the t-case.

There are seals on the transmission shaft and on the t-case shaft, the fluids don't mix, there is also a notch where the two cases bolt together that allow the area to drain.

 

[Jschafer]

What weight on the mobile one engine oil 20-20 ?

 

[dodge cummins]

I Run Mobil 1 In My Auto transmission And My Transfer Case

 

[Forrest]

So you guys are running Synthetic Motor oil in the transfer case? :--) Guess Delo 400 would be ?

 

[dodge cummins]

i run mobil 1 5w40 in my engine,mobil1 atf in my transmission and transfer case and mobil1 75w140 in both diffs. mobil1 is the only way to go.

 

[KB0OU]

The 5w40 is a good mobile one motor oil to run in the t-case. I have seen a list put out by the t-case manufacturer that lists 20-30 wieght motor oil (mineral oil) to use in the t-case. I am not sure when they started putting the atf in them, I think it is a little light for the t-case.

 

[Jschafer]

Thanks

Mine is due so I will give that a try

Joe

 

[CumminsPower98]

I have been running Amsoil 5W30 HDD for quite some time now with no problems. I prefer the heavier oil and figure it should help prolong the life of the gear box.

 

[jrobinson2]

You need to be careful using heavier oil in the t-case, its not splash lubricated like the old days, it has a gearotor oil pump on the output shaft with a fairly small diameter suction pipe and screen, the pipe is close to 6" long and I doubt more than 1/4" inside, imagine trying to suck cold motor oil through a straw, basically the top bearings would run dry until the oil warms up enough to flow through the pickup screen and tube. That said, I have been running 5w50 synthetic in my Dakota's t-case for over 150,000 miles now with no ill effects, I think a light weight synthetic motor oil may be fine but a standard 15-40 may be pushing your luck, especially in cold climates.



Jared

 

[dodge cummins]

not 15w40,he said 5w40 mobil1. the transfer case calls for transmission fluid so i run mobil 1 transmission fluid. its the best for hot or cold temps,it doesn't get thin in super hot applications and it doesn't thicken up in the freezing cold either.