Transfer case fluid

[z28]

Alright here is my issue. My truck has been making a growling noise lately so I figured I should probably check the fluid in my T-case since I've owned it for 5 years and never thought twice about it. I pulled the fill plug and dumped quite a bit of ATF in my drive way. I guess too much is better than not enough Ive have also been loosing AFT from my trans with no visible leak. So has anyone had this problem other than me. Im thinking maybe the out put seal on the trans is bad and pushing it into the T-case. Any thought or experience would be greatly appreciated. Thanks

[okaussiee]

I have an 02 bought brand new in 01. Now has over 200k on it. At 160K the tranny blew some clutches due to no fluid. Had the tranny rebuilt and found that the front seal of the transfer case was bad and sucked all the fluid out of the tranny and into the transfer case. Like you I had no visible signs of tranny fluid loss.

Had the tranny rebuilt and the front seal replaced in the transfer case. Due to the excess tranny fluid, had to replace all the vacuum hoses, the HVAC control in the cab, the front wheel actuator, the vacuum reservoir, the one way valve coming off the intake manifold and the transfer case switch on top of the transfer case.

Caused my front wheels not to lock in, loss of vacuum upon acceleration and my doors on the HVAC system did not work properly.

Everything got contaminated from the fluid.

Sounds like you have your work cut out for you.

Bill

[JaVeRo]

I have one that was doing the same thing. Fortunately I caught it early. The vent tube on the transmission was stopped up causing the transmission to build up pressure forcing fluid past the seal into the transfer case. I ran a new vent line on the transmission up to the fender well beside the blower motor and monitored it since. While I was at it, I ran another vent line for the transfer case.

If I remember correctly, the vent for the transfer case and the vacuum release from the three port valve were connected so I separated them. I stuck a cheap plastic fuel filter on the end to keep dirt out. This all happened about 7 years and 70k miles ago. Still monitoring fluid levels. Transmission and transfer case still original at 203k.

This post has some pictures of that vent tube. When I replace the transmission on the Blazer I did the vent lines the same way as the crewcab.
http://forums.s-10crewcab.net/viewtopic ... ent#p96041

James

[z28]

Thanks yall I would have never thought about all the vac lines. Hopefully I caught it soon enough. The trans was only a quart low and after attempting to check the fluid level in the t case that quart is now in the driveway. I'll have to check the vents as well. My trans vent is up on the fire wall but that doesn't mean it's clean.

[JaVeRo]

My trans vent is up on the fire wall but that doesn't mean it's clean.

If it's still original, the vent by the transmission dipstick is not the transmission vent. It's the vent that comes from the transfer case with another vent from the three port valve Y'd into it.

The transmission vent from the factory is stuck under the wires on the top left of the transmission above where the shifter goes in. About the only way of reaching it to do anything with it is to reach on top of the transmission from the right (passenger) side and pull it that way. Just dont leave it hanging there or you could have trans fluid come out on top of the exhaust.

James

[z28]

I did not know that. I figured the one by the dip stick was for the trans. I'll have to check the one you are talking about. It's to the point it will drain about a quart from the transmission in a week. I'd rather try everything I can before resorting to dropping the t case

[z28]

Update. Found the transmission vent tube. It was burried in a chunk of mud. It definitely slowed the problem now it will drain about half a quart in two weeks. Guess I'll just keep topping off the trans and draining the case every couple weeks for now.

[JaVeRo]

Mine never got that bad. During the summer I check is every oil change. 210k miles and still haven't pulled the transfer case.

Expect it to get worse during the summer then get better next winter.

James

[Horsehammerr]

Where do you check front differential fluid level ?

[LoneWolf04]

The fill port. If it comes out, it's too much. Technically think it's supposed to be 1/2" below.