Transfer case leak repair?

[pushpole]

Just hauled the flats boat up from Florida and noticed a small puddle of transmission fluid on the driveway the next morning, hmmmmmmm. It looked like the tranfer case but could'nt be sure. I drained and refilled the transfer case and cleaned everything up. I parked the truck for a day and no leaks. I put the truck up on jack stands and took her for a 70 mph drive in the driveway.... I found a pinhole leak in the casing (casting porosity?). What's the real deal repair for a leak like this? Thanx!

[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

[fats chevy]

I know of a dealer that does 2 a month. I got my hands on service information (bulletin), after I replaced the rear case. '98-'07 equipped with New Venture Gear TC RPO NP1, NP2, NP3 ,NP4, NP8. Will attach Doc. later.

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

[AverageGuy]

This pump leak repair will eventually be paid for by GM. Here is how this works. Years...perhaps months from now, a lawsuit will occur over the tens of thousands of people who will have to have this repair done on their transfer cases, and GM will admit to this issue in court, and be forced to pay for the damages it caused. They already know this, but will stall paying until they get sued.

They did this on the 3.8 liter GM engine with plastic intake manifold, but it came years afterwords, and guess what??? By then the number of people who saved their receipts had long since lost the receipts or canceled checks which they used to pay for the repair.

SO DOCUMENT YOUR REPAIRS FILE THE RECEIPTS AND WAIT FOR THE NOTICE FROM LAWYERS WHO WILL CONTACT YOU VIA YOUR VIN NUMBER.

I know this sucks, but at least you will get most of the money back someday....if you took care to save the repair receipt and date time it was repaired, and saved the cancelled check or credit card showing who and for what it was for.

This is the new corporate game played by all the manufacturers. If you deny that it is happening until they get a good class action suit against them then years from now they pay, but know that it will be so far out that most people won't bother or won't have the evidence that they had to have it done.

Be smart and be prepared. I know I learned....from the 3.8 liter engine deal and I will never discard a receipt for this type of repair again.

[mattb5150]

This is the known problem reported here in the past. I have the same problem fixed with JB Weld by the dealer that is not holding(slowly leaking again). I guess GM expects us to put up with these defects before 100k miles when my 1993 x-case has 250k miles with no problems.

[linchhummmer]

auto track ii is just blue dexron so when your seal gose out you can see it turn red it dosent matter what you put in it dexron is probablye a little cheaper

[DmaxMaverick]

auto track ii is just blue dexron so when your seal gose out you can see it turn red it dosent matter what you put in it dexron is probablye a little cheaper

How many TC's do you want to buy? Bad advice. Autotrac II fluid IS NOT just blue Dexron. The Autotrac TC's have unique requirements of the fluid. Unlike traditional TC's, they have active syncro's and slipper clutch friction surfaces. Some premium synthetic ATF's claim to be compatible with Autotrac II fluid, but most do not. Put Dexron in your Autotrac if you want, but don't advise others to do the same unless you are offering a warranty with the advice.

[DA BIG ONE]

How many TC's do you want to buy? Bad advice. Autotrac II fluid IS NOT just blue Dexron. The Autotrac TC's have unique requirements of the fluid. Unlike traditional TC's, they have active syncro's and slipper clutch friction surfaces. Some premium synthetic ATF's claim to be compatible with Autotrac II fluid, but most do not. Put Dexron in your Autotrac if you want, but don't advise others to do the same unless you are offering a warranty with the advice.

DM, I had replaced my NP 246 AutoTrac w/new unit. I was informed that I can use full synthetic by seller, not being sure I contacted the manufacture of the unit and an engineer confirmed it was ok to use the synthetic fluid. Nowhere in the packaging was there any reference to any special fluids like Autotrac II just reminder to make sure to fill unit.

I have wondered about the clutches needing some friction inhibitors but now after your post I'm concerned about the synthetic fluid I'm running, am I asking for trouble, or?

[sjd_sd]

my 2002 2500hd had a leak which the dealer claimed came from the seals. They replaced these, and a few days later it started to leak again. This time they said it came from an "upper" seal. In all they charged me $1100. After having it back for a few more days, more leaks. Now they found a "hairline crack" and wanted $1400 for a new housing. I couldn't take it anymore so I pulled the truck out of the dealer and went by the local transmission shop. He found a pin-hole in about 30 seconds which looked like some problem with the way the metal was formed. This mechanic kept it for a day and put some "liquid metal" in the hole. It's been fine ever since and he didn't charge me anything. I would rather drink gear oil than go back to a dealer.

[DA BIG ONE]

Perhaps, a new unit maybe a better choice!

http://www.transfercases.com/

[DmaxMaverick]

Get the dealer to take care of it, even if you are out of warranty. It may be an obvious manufacturer's defect, which allows for some descretion on the dealer's part to help you. Many cases find the dealer covering the repair, or at least a good part of it. If you have a porosity issue with the case, the leak is just the beginning of a more drastic failure.