# 2002 gmc 2500hd leaking transfer case help



## JB2311 (Nov 6, 2008)

my transfer case is leaking from the front by the encoder motor. i think that it is coming from behind the encoder so i removed it and the encoder is wet with trans fluid but i cant see where the fluid is coming from any ideas?? is it common for the case to crack there because i cant tell if i have a small crack or if it is a casting mark ?? i ran the truck but it didnt leak today but there was a puddle of fluid on the ground


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## nascar (Nov 11, 2009)

There is a common problem with the case design. There is a collar on the inside that wears a hole in the case from the inside out. There are tsb's about it. the case has to be broken down and welded then the new part put in.


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## JB2311 (Nov 6, 2008)

i thought that tsb was for the rear of the case mine is leaking from the front under the encoder motor


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## B&B (Nov 4, 2006)

JB2311;954264 said:


> i thought that tsb was for the rear of the case mine is leaking from the front under the encoder motor


It is so it would have no bearing on your issue if your leak is near the front.

You'd first need to determine if it's leaking from the shift shaft seal behind th encoder for sure, or it's possibly emanating from something else nearby. The seal on the shift shaft isn't a common problem and either is a crack somewhere forward unless it was run with the T-case bolts loose or with a severe drive line vibration.

Need to narrow it down a little better.


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## JB2311 (Nov 6, 2008)

I will look at it again today i know that it is not leaking from the endcoer shaft seal that is dry. The gasket that is between the encoder and the t case is wet about half way down the top is dry the bottom is wet.. I drove it yesterday without the encoder and no front drive shaft and couldnt find a leak.


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## stacks04 (Jan 22, 2008)

the gasket between the trans adapter and the t-case could also be leaking. there should not be much fluid circulating in that area, but some does get in there. there also is a seal on the front of the t-case for the input shaft. 

not sure if this is a dmax truck, but they have had issues with the adapter plate craking between the t-case and trans due to bad u-joints. 

where in ct are you? send me a message if your close to waterbury, i could look at it for you. i work at a dealer.


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## JB2311 (Nov 6, 2008)

Ok thanks ill look there, i live in hartford ct thanks


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## JB2311 (Nov 6, 2008)

ok i found a crack it about 2 inches long should i have it welded or should just replace the transfer case???


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## B&B (Nov 4, 2006)

Replace it, either just the case half or the entire unit. Not a good idea to weld on magnesium if you know what I mean. 

And as I mentioned cracks are normally due to loose mounting bolts or driveline vibrations so be sure to take that into consideration.


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## JB2311 (Nov 6, 2008)

i didnt feel any vibations and everything was tight and the case still works what else could cause the problem and crack is behind the encoder motor thanks


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## B&B (Nov 4, 2006)

JB2311;957655 said:


> what else could cause the problem?


Running over something can do it. Been there myself before.


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## stacks04 (Jan 22, 2008)

thats an odd one. i have never seen one do that. you can buy case halves for pretty cheap, or look around you local junkyards for used. just look at the fluid condition before you pay for it. pm me your vin and i could get you a price on the case half.


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## JB2311 (Nov 6, 2008)

thanks i ordered a reman from transfer cases express it cost 980 shipped with a one year warranty with unlimited miles. the case half was 600 so i thought the reman was a better idea thanks for all the help


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