transfer case leak


brian_k24
11-11-2011, 01:37 PM
I have a 2003 Silverado 1500 115000 miles 5.3L Auto Trak transfer case. I changed the transfer case fluid and now have a leak at the drain plug. I used teflon tape and it leaked then tried pipe thread compound (pipe dope) and it stills leaks. Is there a special thread sealant or am I over tightening or something.

gmtech1
11-11-2011, 01:51 PM
It's possible the case it cracked at or near the threads, spreading when the plug is installed.

j cAT
11-11-2011, 06:32 PM
I have a 2003 Silverado 1500 115000 miles 5.3L Auto Trak transfer case. I changed the transfer case fluid and now have a leak at the drain plug. I used teflon tape and it leaked then tried pipe thread compound (pipe dope) and it stills leaks. Is there a special thread sealant or am I over tightening or something.


the plugs in the drain case are made of magnesium. the torque for fastening is about 10 ft lbs. I use a thread sealant made by loctite.

I would not use teflon tape. pipe dope will work.

replacing these plugs is quite common. possible that the threads have issues. dealership will have the correct plug must be magnesium !

your leak could be the transfercase that has a hole worn threw it. this issue does effect some of these transfercases. if you have this issue then the complete case would need be replaced..expensive.

If the case is cracked at the plug area some metal epoxy or marine tex will seal it. If you use marine tex get a heat gun or hair dryer to speed up the hardening process..

post back what is the issue and fix ..

MikeD268
11-15-2011, 06:04 PM
your leak could be the transfercase that has a hole worn threw it. this issue does effect some of these transfercases. if you have this issue then the complete case would need be replaced..expensive.



Not necessarily a replacement job, jc. The leak issue can be repaired but definitely expensive if done by a shop - upwards of $1k to replace a $50 part and repair/epoxy the hole in the case. Truck U covers the issue/repair here (http://www.youtube.com/watch?v=Nj5ZS8wOmNk&feature=results_main&playnext=1&list=PL23F68F1970DAA6BC) on YouTube. However, the leak/hole, in this particular scenario, is going to appear on the top front of the case if I'm not mistaken. If you can drop/crack/repair/re-install the case yourself, like most things, you can save a ton of dough.

j cAT
11-15-2011, 07:32 PM
Not necessarily a replacement job, jc. The leak issue can be repaired but definitely expensive if done by a shop - upwards of $1k to replace a $50 part and repair/epoxy the hole in the case. Truck U covers the issue/repair here (http://www.youtube.com/watch?v=Nj5ZS8wOmNk&feature=results_main&playnext=1&list=PL23F68F1970DAA6BC) on YouTube. However, the leak/hole, in this particular scenario, is going to appear on the top front of the case if I'm not mistaken. If you can drop/crack/repair/re-install the case yourself, like most things, you can save a ton of dough.

if the housing has the hole created by the pump the case will need replacing.

unless you have the proper tools and training this is no a back yard repair job.

other holes in the case most times can be repaired by marine tex or metal mender this would also include transmissions with casting defects causing small leaks.

cracks if small why not try patch it.

the pump leak was patch by some forum members. it lasted for a few months.

MikeD268
11-16-2011, 05:47 PM
One of the few times, so far, that I disagree with you, jc. I'm coming up on one year with this repair professionally performed by a tranny shop with zero problems to date. Haven't seen a drop of fluid yet, knock on wood...

By the same token, it may very well be cheaper to buy a new case half (if possible) and simply replace that. Problem solved for another 100k or so miles...

j cAT
11-16-2011, 06:02 PM
One of the few times, so far, that I disagree with you, jc. I'm coming up on one year with this repair professionally performed by a tranny shop with zero problems to date. Haven't seen a drop of fluid yet, knock on wood...

By the same token, it may very well be cheaper to buy a new case half (if possible) and simply replace that. Problem solved for another 100k or so miles...

so your saying they disassembled the tranfercase and repaired the leak with the epoxy and made the pump component changes to prevent futher damage to the case in this internal wear area at the pump ?

if so I agree with you , it should work out.

If your saying just use epoxy on the exterior of case with where the pump wear is occuring , this will not work for long.

That was what I was saying.

so what did this cost you ?, if they indeed made the repairs that I think your referring to that has lasted .

MikeD268
11-16-2011, 11:29 PM
so your saying they disassembled the tranfercase and repaired the leak with the epoxy and made the pump component changes to prevent futher damage to the case in this internal wear area at the pump ? Exactly. The pump component was the $50 part that they replaced - as painful as it was, I asked the tech if it was true. He confirmed it. Unfortunately, it cost over $1k to get the t-case out, epoxied, pump replaced, and back in again...

You're correct, though. If the hole was simply epoxied from the outside and the pump not replaced the issue would just continue to get worse...

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