What fluid should I use in my dana 20 Transfer Case w/auto th400?

[76cj7chick]

Hi all,

I checked my Transfer Case fluid and it looked like Transmission fluid... Is that correct?
Or am I supposed to use gear oil?

I have a 76 CJ7 with a 3 speed Automatic GM Turbo 400 Transmission and a Dana 20 Transfer Case , both of which are out of a FSJ truck

I've heard the oil is shared between a MANUAL Transmission and the Dana 20 Transfer Case but, would an automatic tranny and Transfer Case do the same?

 

[jdcaples]

For what it's worth, Novak Conversions recommends conventional mineral oil or a para-synthetic if you can't find conventional mineral oil: 80W-90, API-GL5 or MT-1. I think most Seattle NAPA stores have a suitable lube on the shelf.

-Jon

Citing the source: http://www.novak-adapt.com/knowledge/dana_20_rebuild_guide.htm

 

[Old Dog]

As far as I know all the gear driven t/c's (Dana's 18, 20, and 300) use 80-90 gear oil. Some of the newer chain driven t/c's do use ATF.

 

[tarry99]

Hi all,

I checked my Transfer Case fluid and it looked like Transmission fluid... Is that correct?
Or am I supposed to use gear oil?

I have a 76 CJ7 with a 3 speed Automatic GM Turbo 400 Transmission and a Dana 20 Transfer Case , both of which are out of a FSJ truck

I've heard the oil is shared between a MANUAL Transmission and the Dana 20 Transfer Case but, would an automatic tranny and Transfer Case do the same?

76CJ
Neither Manual or Auto's share the same oil in your vintage Jeep. .............especially the Dana 20 Transfer Case there is a seal and gasket between the two..............should be gear oil in the Transfer Case @ 80-90w and Auto Transmission fluid in the Transmission . Get it correct or it will hurt the Transfer Case .

 

[76cj7chick]

Ah ! (Pardon my French)

Stupid po! I guess I have to get some gear oil for the little guy.
Any recommendations on how to drain the atf out -- besides through the drain plug?
Is it wise/okay to spray brake fluid cleaner in the housing and then fill with GL-5 gear oil?

Everyone thanks for the help!:ty:

 

[jdcaples]

I wouldn't put brake cleaner in it unless you want the learning experience of removing it, inspecting it and maybe rebuilding it. I'd opt for an "in situ" transfusion.

If it were me, I'd just drain it, fill it with the proper gear oil, drive it for a mile or or so, drain it again, fill it and drive like there was never any ATF in it.

I bet most people would just drain it (with the drain plug), fill it and drive with a small percentage of ATF-tainted gear oil.


-Jon

 

[76cj7chick]

I wouldn't put brake cleaner in it unless you want the learning experience of removing it, inspecting it and maybe rebuilding it. I'd opt for an "in situ" transfusion.

If it were me, I'd just drain it, fill it with the proper gear oil, drive it for a mile or or so, drain it again, fill it and drive like there was never any ATF in it.

I bet most people would just drain it (with the drain plug), fill it and drive with a small percentage of ATF-tainted gear oil.


-Jon

Hi Jon!

Thanks for sharing your wisdom. I will have to do that. Poor lil jeep. 00xx

 

[hagar]

After you drain and refill the Transfer Case , verify the fluid levels of both Transmission and Transfer Case , making sure they are full.
After 500 miles or so, check the auto Transmission fluid to make sure it isn't low, or the Dana 20 level to make sure it's not overfull with ATF again.
There are two seals inside the adapter between the T400 and Dana 20 ; one to keep ATF in the T400 and one to keep 80-90 in the Dana 20 ; if they are leaking, or missing, or only one is installed, the problem could happen again.
Just an FYI.

 

[76cj7chick]

After you drain and refill the Transfer Case , verify the fluid levels of both Transmission and Transfer Case , making sure they are full.
After 500 miles or so, check the auto Transmission fluid to make sure it isn't low, or the Dana 20 level to make sure it's not overfull with ATF again.
There are two seals inside the adapter between the T400 and Dana 20 ; one to keep ATF in the T400 and one to keep 80-90 in the Dana 20 ; if they are leaking, or missing, or only one is installed, the problem could happen again.
Just an FYI.

Hi Hager,

Thanks for the suggestion. I will do just that. However, I wish I had checked the Transfer Case oil when I replaced my Transmission fluid and added a deep tranny pan to it...