Transfer case leak repair?

[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?

[DmaxMaverick]

If you are using a quality synthetic, it's probably be OK. I was referring to the labels of the synthetic brands. I've seen the result of dino ATF in a 246, and it wasn't pretty. The clutch surfaces were coked, and the syncro's were scored pretty bad. I suspect dino fluid fails at the temp of the friction surfaces during operation. Much like a failing auto tranny when it starts to slip, the fluid gets cooked in the hot spots. I know of a few using Amsoil and Mobil 1 synthetic, and they seem to be fine. Contact the supplier of your fluid to confirm compatibility, but I wouldn't lose sleep over it.

[More Power]

A new article was uploaded to the web site a couple of days ago that relates to this subject - of preventing a transfer case fluid leak...

http://www.thedieselpage.com/reviews/tcase.htm

Jim

[townecho]

I just got word back from GM and the dealer, they'll cover the repair of my transfer case but I have to pay a $300 deductible. Basically I'll be paying for the parts and they'll cover the labor. I'm happy since the parts would have cost me around $400 if I had fixed it myself, plus it won't cost me more $$$ if they find damage inside.

deep vee,did you deal with chevy or gm dealer in flagstaff?mine just p.h.ed at 160k.initial visit with chevy dealer was retail minus 10%.1/2 million miles should not happen.just the presence of the shield indicates a problem with tolerances.

[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.

[Duraswede]

i have the same problem, a little hole in the case.. i filled it up and it leaked out within a month, only while driving, so i cleaned the surface around the hole and sealed it with "chemical metal" it was OK for a week but now i see that it's leaking again, so i wonder if ther's any pressure behind this hole? is there an oil pump there that builds up pressure?
and what does a new rear case casting cost? is it possible to replace without taking down the transfer case from the truck?

[afksman]

First, thank you all for the long-long thread that is full of information on this TFC leak.
I have an 03 Z71 (sorry its gas, all I could afford back then) with 135,500+ miles. For the past month I’ve been hearing a strange sound, Sort of like a U-joint with a bunch of twine wrapped around it. Today I had the truck up on the lift doing a complete underside fluid change. To my horror the TFC was bone dry with no evidence of leakage (or metal shavings from what I could see). After servicicing I did my normal 1/2 mile drive-stopped and looked underneath I was seeing ATF drip from the TFC. My first thought was somehow in my rush to finish up I may not have fully tighted the fill port, nope it was dry. I could not see where it was coming from. After reading this thread I now know why, not leaking when stopped). When I got home and looked up under there, wow!! for those of you who may have turn wrenches on leaky military birds, it looked like the underside of 130's wing. I found the little hole and came to this forum to search for an answer.

I have the NVG 263 TFC.

Question, I've never worked on a TFC, but I am an A&P with 18+ years of turning wrenches so I’m not too scared to tear into it. Will I need special tools for the repair and installation of the Adapt-A-Case fix? Does anyone have a list of consumable parts such as seals or internal parts that need to be replaced once the case is split? This truck is my only transportation and once it goes down for maint I have no way of making a trip back to the parts store for that "oops, I forgot" part. Any help would be greatly appreciated.

Edwin in Kansas

[More Power]

Other than a seal driver and a jack to hold up the transmission, a typical well-equipped tool box should be sufficient. Get a buddy to help with the R&R.

Driving in a new output shaft seal can dislodge the circular spring surrounding the lip-seal if you're not careful. It's got to be in-place to seal correctly.

• Transfer Case Adapter Housing Gasket (you'll need a new one, they usally break when separating the transfer case from the trans)
• Rear Output Shaft Bushing (replace if this is a high-mile truck)
• Rear Output Shaft Seal (replace if >50K miles)
• Silcone RTV gasket sealer
• Brake cleaner

Jim

[afksman]

More Power, thanks for the info. I'll go out to the net and order that part from kennedy diesel. I did some research and have found that other than the weight (two person or jack) this is a pretty strait fwd job. I'm putting a JB weld bandaid on today to stop the bleeding until I get the part and can put the truck down for maint.

Thanks again.
Aim High U.S. Air Force

[todd.walter]

I had (have) the same problem on my '03. The previous owner had done a JB Weld repair that had peeled off. I think the constant pressure/vibration from the pump is what causes the JB weld to peel. I cleaned up the case down to bare metal (used a dremel with a sanding attachment around the hole). I also got some black RTV and did a little patch right on the hole first. This is partly to help seal but is really intended to provide a shock absorber between the pump and the JB Weld. After the RTV set I applied JB Weld over the clean and prep'd metal. Now the pump vibrates on the RTV and the JB Weld holds the RTV in place. It has worked well for over a year (although I developed a hole from one of the other pump tab points and had to do a second repair for the second hole). Some day I need to replace the back case half but till I find that lotto ticket I just keep an eye on the box and check the level frequently.

[KrazyNate]

105k on my 02.. Thank God I noticed it before catastrophe.. Ironically, I replaced the output shaft seal about 15k ago, and a complete fluid service about 5k ago and noticed no abnormal ATF since doing the seal. Im guessing its relatively new leak at this point..
It looks painfully obvious that GM is playing dumb for most of you on this one, so my problem at this point is that its Saturday morning, and no shops are open to take my complaint.. I need this pick up tomorrow and am going for the JB redneck fix.. Do you think this will detour a possible GM or dealer coverage of cost when I take it in next week?

Been pretty unlucky with my Dirty, but it is soooo nice to drive..

[hrsedrvr]

i too have that problem, i was recently to the allison dealer for trans service( rear case cracked $1300.00 later) and they told me about the little hole in the transfer case. they said it is common and caused by the small pump inside which is mounted on a couple studs and it will come loose and move around and eventually wear a hole in the case. they said it cannot be welded becuse the case is magnesium. estimated cost to repair is $1500.00 but they said as long as it's kept topped up it will last

also i am beginning to get trans slip if i start off hard throttle when it shifts to second it's like neutral untill you let off some. is this the beginning of the end?

[More Power]

When researching this problem I learned that magnesium can be welded, but not by just anyone. The metal has to be heated, melted and new material added just at the right temp point. Too high of temp and it'll combust. I've read that burning magnesium can be quenched in a bucket of water.

If anyone knows of a good magesium welder, post their contact info here.

Jim

[todd.walter]

I hope you are kidding about extinguishing burning magnesium with water. It burns too hot and will actually split the water into hydrogen and oxgen. These will then explode (forming water again).

As a side note. I eventually pulled my T-Case and rebuilt it (chewed up shift forks were causing it to jump out of gear). When I replaced the back half of the case I found a THIRD hole that had formed (after I JB Welded the first two). I put in a Kennedy setup to prevent a repeat on the new back case half when I reassembed the case. The JB Weld (with RTV underneath) held for a lot of miles but once I had one hole the oil pump kept working it's way through the rest of the case over time.

[More Power]

You are correct. Water should not be sprayed on a magesium fire. I remember reading about mag welding some time ago, and the author recommended a bucket large enough for total immersion as a suitable fire extinguisher for magnesium. I couldn't locate that page now, but I did find the following at this link.

Class D [fires]
Class D fires are combustible metals, such as magnesium and titanium. Water in large quantities, as high velocity fog, is the recommended extinguishing agent. When water is applied to buring class D materials, there may be small explosions. The fire fighter should apply water from a safe distance or from behind shelter. Metal fires on board ships are commonly associated with aircraft wheel structures.

So, what do commercial welding shops do when they have a magnesium fire?

My final word... Unless you're a trained professional, I don't recommend anyone attempt to weld magnesium.

Jim

[Xmas1]

I recently lost the output shaft bushing on my transfer case and lost all the fluid. When I drained the fluid I only got about 4-5 TBL spoons of oil, and some metal. I decide just to replace the Transfer case with a rebuilt one from GM. It took 5 days to get it in, $1,230.00 and I needed the truck so I was ready to install that night. When I picked it up I noticed that the rebuild had (you guessed it) an epoxy repaired rear case. It turns out that the rebuilds aren't even from GM they came from a repair shop in IL. I called both the repair shop and GM and it's considered a certified repair to fix the case with epoxy. I considered sending it back for another one but I would probably only get another epoxy fix after waiting another week.
The rebuilds do have the update kits in them but I'm not crazy about the repaired case. It's just something else to worry about. There is a 24 month waranty but it still doesn't sit well with me. I've decided to keep my old case and rebuild it myself and take the hit on the core cost.
Has anyone else noticed the epoxy repair on what's considered a rebuild?

[Willcoc]

I purchased a new half of a case for my 01. Then took the one to shop to have the hole welded shut. Looks good but don't really need it now. If anybody would like this case, cover shipping cost and it is yours. Send me a PM if you would like it.

[mattb5150]

I'd like to have your welded case half, check your PM.

Matt

[Hawker]

Well it appears I have joined the masses (hundreds of thousands) of GM transfer case owners which have the famous pinhole leak on the right side of the tail shaft case and after much investigation happens to be a NV246. Thanks for putting all this information on the board here it really educated me about this issue!

My 1999 GM Suburban has 160,000 and I noticed a sound like a hub cap popping at about 25 mph a few weeks ago. The noise got irritating to the point I removed the outer rings on each wheel no luck. I put the vehicle up on 4 jack stands and put it in drive (transfer case chain noise) opened the drain plug and completely dry. Just had it checked at the dealer on the last oil change and it was full I found part of a broken metal clip?

I used JB weld as a temporary patch when I found the hole after refilling the case and replacing the tail sahft seal for the 5th time since owning it. I had no problems with the JB Weld going on three weeks but after reading all the post here I elected to get a rebuild from GM.

I contacted GM @ 1-866-453-4123 asking about this issue and what was done to resolve it. I was assured that if there was a hole found on the rebuild they would replace the tail shaft case in the rebuilding process. Parts guy at GM dealer was also told this.

Well I got my rebuild transfer case today and already being aware of why GM has gone belly up with continued lies lies lies. I immediately found the epoxy patch GM did and it was found in exact same location as the one I was replacing. I was pissed about this and so was the parts guy. I asked if the dealer could simply remove the tail shaft on the rebuild and send it back to GM to shove up GM's lying A#$h)les. Parts boss said no dice but I was given the option to spend another $400.00 for a new tail shaft case to go with the rebuild. Parts guy said he was posting a notice on their parts network advising all local area dealers what GM was doing. Other members of this board warned of this in other post of this very subject and I thank you!

It really does not matter in my opinion GM has burn't both ends of the candle by short changing customers for years with shoddy workmanship and crap like this. GM also tried to hide this patch by repainting the case with thick silver paint so it is hard to find unless you have patched the transfer case yourself and know where to look.

I now had two choices today after getting the rebuilt case. I could elect to keep my existing transfer case and replace the tail shaft case with the aftermarket part through Kennedy Diesel I bought. Or I could just install the so called rebuilt case I purchased through GM? Hmm

I reluctantly went with the rebuilt case today because of the warranty. I did ask the dealer to install the Kennedy spacer of which GM advised me would not affect the warranty. The dealer was impressed with the part as it fit exactly as shown on Kennedy Diesel site.

What is also interesting is that when the mechanics at the dealer separated the rebuilt case the same clip was found in the exact location where that patch was. I was there and witnessed this. I had removed the old clip and compared it to the new one. Nothing changed and another lie by GM. An advisory on the part list from the dealer advises this clip needs to be purchased in addtion to the rebilt case? Whoa how screwed up is GM selling the same clip not only included in the transfer case but advising you need to purchase another one?


Nope as for me I will never buy a GM again And I have been driving GM for over thirty years. GM is crying out to everyone they are reinvented?
GM is just remastering the art of BS.

[Hawker]

Well you are correct about the lawsuit on the GM 3.8 I turned in my paper work well before the deadline last Oct. 2008 on my buick century. I have heard nothing. Went to the Gibbs law office that filed suit. They sent me a genric message that basically I read between the lines that say I ain't gettin nothing Gibbs got paid but Iwill not. GM now bankrupt oh so sorry.

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.