Transfer case leak repair?

[Renomax2001]

I noticed a leak coming from the 4wd transfer case right at the 3rd bolt at the seal and know it is not trans because I just changed the transfer case fluid (gm 12378508) Auto-Track II, and it is a purple fluid.
I have 66000 on a 2001 Durmax 2500hd. Would like to know if any similar problems and the est. cost to fix at dealer. I have a friend in the 4wd repair business, should I get est. from both?
Thanks

[More Power]

Your transfer case (either manual or pushbutton electric shift) requires 1.9 qts of Dextron ATF. You don't have an Auto Trac transfer case...

"3rd bolt at the seal" Is this where the transfer case bolts onto the Allison?

Has the transfer case been out of the truck before?

Jim

[Renomax2001]

Jim
In my 2001 diesel supplement manual on page 7-51 it has Auto-Trac II Fluid in the fluid lib past.
The leak is coming from the 5th bolt from top out of 17 bolts about 1ft. in front of drive shaft.
Transfer case has never been out of truck

[More Power]

Oh contrare....

There are a number of confusing issues regarding recommended fluids for these trucks.. However, this is one we're sure about....

Page 4-420 of the 2001 GM service manual lists the various requirements for the NVG 263 "Selectable" NP1 transfer case (the pushbutton version), as well as the NVG 261 2-speed manually shifted NP2 version.

Both transfer cases require approximately 2 qts Dextron III.

There are no "automatic" transfer cases used in the 2500HD/3500 trucks. Your choices are either 2-speed manual or "selectable".

Jim

[Renomax2001]

Jim
Thanks for explaining the transfer case ie. (manual and auto). I was confused because I thought the push button instrument panel was the automatic I understand that the Auto 4wd has the button "Auto 4WD" on the instrument panel. A 4wd expert I am not.
In the photo you sent the leak is coming from one of the bolts shown, it is about 2 bolts lower, (behind the frame) in the photo.
Thanks again. I will look for your reply.
Steve

[More Power]

You could do a search for leaks in this forum, but I don't recall a bolt leak (or near a bolt leak) on the transfer case. There have been case porosity issues with a few early Allison transmissions that resulted in leaks at a couple of bolts (behind the torque converter).

If this is out of warranty, I'd eliminate a possible case defect as a cause as a first step (i.e. crack etc.). If that's not the problem, I'd pull the offending bolts, then seal them using a bolt thread sealant (it's like Teflon pipe dope), and/or possibly install a copper washer (GM pn-10139097) under the bolt head.

The copper washer trick is how GM solved some of the early (pre 11/03 build dates) Allison bolt leaks.

Jim

PS. You are correct about the diesel supplement mentioning Auto Trac fluid for the transfer case..... My 2001 diesel supplement mentions the 6.5L diesel as well... Seems a few bugs found their way into the various books and manuals. I use Dextron in my truck's transfer cases. [img]smile.gif[/img]

[Renomax2001]

Jim
Yes I have searched this forum and found the post with the bolts problem at the torquec converter.
If that were the problem in this case, would the leak be somewhere else?
I am taking it in today to get a the problem diagnosed at my service dept. and will report there findings.
Thanks again for your help and education.
Steve

[More Power]

Mentioning a bolt leak behind the Allison torque converter was only intended to illustrate a problem somewhat similar to yours, and provide information that might solve your transfer case leak problem....

Jim

[Renomax2001]

In the above photo the spring that came loose or broke off wore a small hole at the indention left and back there you see the wear.



Above and close to the center of the photo you can see the hole about 3 inches above the 3rd bolt and right below the dirtiest part of the case.
Just picked up truck from service dept. with a $1,280 bill.
The problem was a spring came loose from fluid pump inside the transfer case and caused the tention to wear a small hole in the rear half of the transfer case at the drive shaft.

Steve

[ 01-28-2006, 03:49 PM: Message edited by: Renomax2001 ]

[linchhummmer]

the exact same thing happed to my 01 lb7 i got a small hole in the tcase and the fluid leaked out and the truck sat in the shop for like a month before i went and picked up and just drove with some jb weld over the hole but they told me that sh!t off the road hit it and did it, it was probably the same thing that happened to yours that happened to mine