T-case making oil???

[BlkMax]

This is a question on a 1997 GMC 4x4 Suburban with a NP243, and the 4 speed auto. I bought it for my kids with 200K miles, and have been slowly going through the rig.

When I went to change the oil in the t-case, I removed the FILL plug and had a LOT of red fluid drain from the fill. This was NOT an overfill condition, because there was no way someone could get that much extra oil in the t-case based on the way it was arching out of the fill hole.

The information that I have says the t-case takes a GL5 gear lube, and the stuff draining out was not gear lube.

I am thinking the only way that much trans oil could get in the t-case is from a bad seal on the tranny output shaft.

Is the only way to fix this to drop the tranny and fix the seal?

Any ideas would be appreciated.

 

[Chevy1925]

is the tranny fluid low?

if your pretty darn sure its "making oil" then yes, your gunna have to drop the t-case and replace the trans output shaft seal. if would probably be a good idea to replace the t-case input shaft seal as well. careful though cause if its makin oil that way, the adaptor plate may be full of trans fluid.

 

[Mike L.]

Actualy it should be the input seal on the TC. The trans does not have a rear seal.

 

[Chevy1925]

Actualy it should be the input seal on the TC. The trans does not have a rear seal.

really! wish i would have worked on more 4wd trans to know that lol :hug:

 

[BlkMax]

Actualy it should be the input seal on the TC. The trans does not have a rear seal.

That is actually good news! I do not have to deal with the tranny.

Thanx Mike :thumb:

 

[xcablb7]

Actualy it should be the input seal on the TC. The trans does not have a rear seal.

x2 common problem with those seen a few trans wrecked from this no visible leak but out of fluid

 

[THEFERMANATOR]

The information that I have says the t-case takes a GL5 gear lube, and the stuff draining out was not gear lube.

The transfer case uses ATF in it as well. All of the new process aluminum transfer cases that have a pump in them to circulate oil use ATF except for teh AUTOTRAC which uses the blue smurf oil as they call it at GM.

 

[Redbowties88]

i guess there's no speed sensor hole in the np243?

 

[THEFERMANATOR]

i guess there's no speed sensor hole in the np243?

It has one just like the DURAMAX does.

 

[Chevy1925]

i guess there's no speed sensor hole in the np243?

Thats why i asked if he checked to see if the tranny fluid was low lol, just incase someone prior to him had done it that way

 

[Redbowties88]

yea....lol i always have 3 quarts in my t-case