Ok, well its not pretty....

'05 Avalanche 2500. 8.1/4L85E/NV246.

Was leaking fluid out the output seal, or so I thought. 800 mile trip this weekend so I popped a new seal in Monday night after work. Was done a lot on Autotrac II (1.5 L) so I topped it off, and called it a night.

Tuesday ran great, got home late, fresh Autotrac II dripping off the case. Seal was dry. I inspected for a hole, could not find one.

Wednesday night. More fluid dripping off the case. Looked for twenty minutes, no obvious holes. Seal still dry. Looks like it is leaking between case halves except.........

Filled it up, down ~ 150 ml. 140 miles, two days, not leaking at night. Think that is too much fluid to be coming out the case halves. Likely pump rub through a hole i can;t see.

Plan is to still take the trip but top off every 200 miles. Any pictures of the holes location? I wouldn't mine epoxy it or something. How long does that repair typically last?

Next thing, this is my DD in the winter and tow rig in the summer. I really can't jack around with half-assed repairs or significant down time. Looks like $300 for a case half and $70-$250 for pump repair kits. Or Merchant Automotive offers an upgraded case, for a decent price, and since i am not mechanically inclined, I was thinking of going that way.

Any experience on Merchant Automotive? ANything else I should know? Am I way off base? I called GM dealer last night and they said there was no TSB/extended warranty. I would complain about 62 000 miles (and a year of payments left :() but I had a 13-54 blow in my Ranger at 80k and a 231 DHD let go in my Dodge at 50 000 miles, so I am used to it.

The hole is VERY HARD to see sometimes, but when you do find it, you will know.

The hole could be just a hairline crak, but when you push on it with the tip of a pocket knife, it will open up.

Look at your case, count 5 case bolts to the passengerside from the drain hole, and look to the tailshaft housing, there is a small bump that is the pocket that holds the pump housing inside the case. when yopu find it, scrape all the gunk away, and keep scraping and poking, i9f there is a hole, you will find it. it does sound as if you have the pump rub problem.

Good luck, and let us know!

Here is a link to how I did my repair, I jknow you have the Auto Trac case, but it is prone to getting the hole as well.

http://www.dieselplace.com/forum/sho...d.php?t=140732

I have had the hole on the side of the case for about 30,000 miles. I use some high end goop to fill the hole. It will leak about every 15,000 miles and I will clean it up and do it again. I know it needs to be fixed the right way.

The problem that I am having now is that it is leaking on top of the case. Is there one spot that I should be looking for the new leak?

Thanks for your time.

KR

Pm sent.

Dan

I had a total of three holes at three different locations in my t-case. I fixed two of tem with JB Weld and the third one I found when I replaced the case in December. he external repairs will work, but fixing it right requires one of the internal upgrades too.

-Wardster

x2

the pump has four tabs, so you can have up to four holes after time (2 on bottom, two on top ish)

JB welding the case is fine (though a case can be had for $200 from tptrans), IF you install a case saver plate or M/A pump. None of it is very hard to do. Just have your snap ring pliers handy :)

I was wrong. My first hole was 5 bolts over from the drain plug. My new hole is 3 bolts over from the drain plug.

http://i141.photobucket.com/albums/r69/b4wscrambler/stuff001.jpg

I have not had good luck with JB weld so I use some high grade silicone.

I also keep this bag in my truck just in case I need to make a repair on the side of the road.

http://i141.photobucket.com/albums/r69/b4wscrambler/stuff002.jpg

In the bag I keep every thing I would need to patch a hole in the t-case and refill it. I also keep a fuel filter and wrench.

Great stuff guys! I actually have a big block so no need for the fuel filter (or no way I can drop the tank anyway. :p:)


I figure if I pull the case to repair it, I should do the case half and the pump saver. I read the instructions on the Merchant site and it didn't sound too hard, but it looks like a solid 6-8 hrs, and if I screw it up I am hosed.....

I think I will do a rebuild with the case saver. I don't think mine is hurt, but I did run it low, so who knows, might be worth to start over with new internals. (no noises, rattles, or loose parts).

I will check the case when I get to my destination. If I still can't find the hole, I will jsut keep filling it and get parts/case order next week.

Unfortunate expense at this time but what can you do.

Found it! 5 bolts up. Pinhole.

I covered it in rtv sealant. (only thing I had, and am leaving for Utah right now). Hope it helps some, will scrape it off and epoxy it when/if I get there.

WIll get a new case lined up when I get back. Thanks for the input Dan!

You guys crack me up!