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-   -   Leaking Transfer case Fluid (https://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/leaking-transfer-case-fluid-473037/)

dmelvin Nov 29, 2010 01:08 PM

Leaking Transfer case Fluid
 
Hey guys,

I just noticed today that I'm leaking transfer case fluid, it looks like the output shaft seal, how big of a pain in the ass is thing going to be to change?

Country Boy Nov 29, 2010 01:34 PM

The seal is easy. Just pull the DS and then pull the seal out and replace it. Careful that its not the dreaded hole in the case.

dmelvin Nov 29, 2010 04:04 PM


Originally Posted by Country Boy (Post 4586578)
Careful that its not the dreaded hole in the case.

"The" dreaded hole... are these known to have problems?

BLUES MAN Nov 29, 2010 05:32 PM

my is leaking also bro, altho mine has sat for 6 months, so thats probably why. but like stated above its very easy to change.

08k1500_3 Nov 29, 2010 05:46 PM

First, yes we have issues with the t/cases. The "dreaded hole" that they are talking about is the fluid pump wears thru the aluminum of the rear case half. If that is the case there will be alot of fluid coming from higher up than the output seal that you think is leaking. If you look hard enough on here there are multiple threads on this subject.

The output seal is also a common leak point. Just remove the driveshaft and pop the seal out and install a new one, be sure that the vent hole of the seal is pointing down.

Also repeat seal failures and leaks are usually due to a worn rear output bushing inside the case.

Country Boy Nov 29, 2010 06:10 PM


Originally Posted by 08k1500_3 (Post 4586741)
First, yes we have issues with the t/cases. The "dreaded hole" that they are talking about is the fluid pump wears thru the aluminum of the rear case half. If that is the case there will be alot of fluid coming from higher up than the output seal that you think is leaking. If you look hard enough on here there are multiple threads on this subject.

The output seal is also a common leak point. Just remove the driveshaft and pop the seal out and install a new one, be sure that the vent hole of the seal is pointing down.

Also repeat seal failures and leaks are usually due to a worn rear output bushing inside the case.

The case is actually Magnesium, not aluminum...

Yes, its a very common problem and it will affect every case that is known to have issues. Its a design flaw unless its fixed.

08k1500_3 Nov 29, 2010 07:03 PM

Yeah that is completely correct County Boy..

It is alot easier to take the case apart and install the updated pump clip and fix it for sure before you ruin the case

dmelvin Nov 29, 2010 07:15 PM

Well, as you all said, the seal was cake-work to change. However, the seal that I pulled out appear to be in good shape, no noticeable cuts or nicks. DS yoke also looked good.

This makes me nervous because I chucked the driveshaft a couple of months ago (the slip yoke snapped where it holds the u-joint).

The leak is no higher than the seal, because there is 0 fluid anywhere above the seal.

We'll see how this goes, hopefully this was the problem... the only thing that I did notice on the seal was there was some sediment on it... but that could have come from the case when I pulled it out.

budhayes3 Nov 29, 2010 08:23 PM


Originally Posted by 08k1500_3 (Post 4586794)
Yeah that is completely correct County Boy..

It is alot easier to take the case apart and install the updated pump clip and fix it for sure before you ruin the case

I replaced the clip in mine as preventive maintenance when I swapped my trans back in May...I have pics of it in my "FLT Level7 is finally here" thread in this section...

dmelvin Nov 29, 2010 08:31 PM


Originally Posted by budhayes3 (Post 4586881)
I replaced the clip in mine as preventive maintenance when I swapped my trans back in May...I have pics of it in my "FLT Level7 is finally here" thread in this section...

I'll look into that here shortly... Also, on a similar/slightly unrelated note... the fill plug for my transfer case is completely destroyed (There's no way it's coming off)... so I've been filling my transfer case from the speed sensor on the passenger side... I had the driveshaft pulled when I started putting fluid in, and if I went just a little too fast it came pouring out of the t/case where the yoke slides in... I'm sure that's normal, however, makes me wonder if maybe not all of my transfer case fluid is actually getting in the case.

And if this is a huge disaster waiting to happen, let me know, I've never cracked one of these open and I've never looked into any kind of schematics for how everything is laid out in them... perhaps I should buy a chilton or something...


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