View Full Version : Anyone with a pre-2007 Duramax?

06-16-2014, 01:15 PM
You need to know about this problem. I didn't know about it, and just had my output shaft bushing come completely out of my transfer case on my trip back from Montana this past weekend. I am not sure what I'm going to do, but I drove home okay. My truck has 163K miles on it. Apparently this is another one of those KNOW problems that GM won't do anything about for their truck owners.



I have never seen any oil come out of my transfer case. Apparently it only comes out while driving, and can trash the whole transfer case if you're not careful. There is a kit made that will prevent the hole if it hasn't already popped through like mine has. Otherwise you have to replace the rear case and install the kit in it. With 163K I'm not sure if it makes more sense to get a rebuilt transfer case with the fix already incorporated.

06-16-2014, 03:54 PM
Wow...is or was there a recall on this?

06-16-2014, 06:08 PM
No recall, not a goddam thing from GM. They leave their customers to deal with this, and as far as I know there wasn't even a service bulletin on it. If I would have known about it I could have prevented a trashed transfer case. The bastards have known about this for over 5 years. Seems like they should have sent a letter to all owners to warn them.

Also, I found out that this affects a LOT more GM models, not just the Silverado 2500HD. Other transfer cases (mine is the NP263XHD) also have this problem in Avalanches and other GM 4WD vehicles.

Today I decided to drain the fluid from the transfer case and put new fluid in, then try to replace the output bushing and seal, and see what happens. I pulled the plug and only got about a tablespoon of ATF out of it...supposed to be two quarts. There wasn't a trace of ATF anywhere on the bottom of the truck that I could find. There was just a little below the hole in the case. I don't know how I got home from Montana without seizing the whole unit. Honestly, I have never checked or changed the fluid in it...I guess I assumed a transmission flush that I do ever 50K took care of it. I didn't realize, or even consider that it was a totally separate unit. Not sure it would have mattered anyhow with this problem.

The truck still seems to drive okay, but now I'm thinking I need to replace the transfer case....$1500 for a rebuilt one. To fix the case problem would be $300 for just the rear case half, $100 for the parts to prevent this from happening again, and who knows what else I would need internally that's worn or trashed due to lack of lube. Then there's the labor to R&R. I'd just as soon get a good unit and be done with it.

I guess after I replace it I need to have a maintenance schedule. I've never even changed the differential fluids, but they're going to get changed too. These engines are designed to run 300K miles, but the rest of the drivetrain might not without some fluid replacement.

06-16-2014, 06:11 PM
163K miles, buy a new truck.

06-16-2014, 06:16 PM
163K miles, buy a new truck.

A new truck is $55K+. The transfer case is $1500 and the truck runs great otherwise. The Duramax should last twice this mileage, so I'm told.

06-16-2014, 07:18 PM
Surprised that a 2003 model doesn't have cosmetic issues too. That was as much the reason I got rid of my 95 when I did as anything. Paint problems as well the plastic trim on the doors among other things.

My 2009 looks like the plastic trim/guard on the doors is starting to deteriorate now. Noticed it when I was looking over a self inflicted scrape on the RR door recently. Curiously, just one side (passenger).

06-16-2014, 08:11 PM
The only cosmetic issues my truck has are from normal wear and tear, like door dings. I've had it in the shop twice for re-paint due to accidents....one time I backed it into my trailer which caused re-paint of the driver's side bed, and another time the entire right side was re-painted when a deer "bounced" down it and trashedf the fender, dented both doors, and dented the bed. But the original paint looks as good as the re-painted areas. I have had problems with the tape on the side mouldings not sticking. The body shop has fixed that twice now. The interior is still pretty nice for a 2003.

06-17-2014, 06:12 AM
Wow, I am still driving a 72 Blazer and Cheyanne Super and a two 87 4x4 trucks and for 55K I can keep throwing new fenders etc on them. My NP 205 in the Blazer does not leak a drop, however the 208s in the 87s leave little puddles when parked for an extended period. I change fluid in axles transfer and trans every couple years.

06-18-2014, 05:53 PM
Sorry to hear about your issues during your travels Laszlo, do you know how far back in years this issue goes back, just curious if it could affect my 2004 GMC

06-19-2014, 08:34 AM
Marty, yes your '04 is probably affected. Apparently this doesn't affect only the NP263XHD transfer cased in the Duramax trucks. It also affects the NP263, NP263HD, and others. There's a tag on the back of your transfer case that tells the model. The problem is because GM used magnesium for the rear case halves.

I noticed a slight hum coming down Lolo Pass into Lolo, MT an it got progressively worse on the way home as we went through Butte and it was vibrating badly. I slowed down to 65 MPH and it was still there, especially under light load. It was better under heavy load. In Livingston we stopped at a rest area and took a look under the truck and saw the bushing on the front of the driveshaft but no oil. I should have checked the oil at this point but the damage as really already done. Since it was Sunday, I didn't know what to do but keep driving. I found that when I speeded up to 75 MPH it got better so we drove the rest of the way home. Little did I know the oil was going away. I didn't even see it on my trailer so I have no idea where it went, nor how long it has been coming out. I'm still amazed we made it home.

I ordered a rebuilt transfer case yesterday and it should be here Friday. I was going to rebuild it, but I got concerned that there was more wrong than a rebuild kit would address and I need to get the truck back running so I can go sheep scouting.

Watch the videos I linked. There's a lot more info on the web about this problem. Unfortunately, GM expects all owners to disassemble their transfer cases to put the fix in before they fry them. I think they should have sent a letter about this to every owner. They don't say this "might" happen, it WILL happen somewhere around 150K -200K miles. The guy I bought my transfer case from said he's rebuilt hundreds of them.

06-19-2014, 08:37 AM

Apparently all of these vehicles have the issue:

Application table.


1500, 1500HD, 2500, 2500HD, 3500
NP246, NP261HD, NP263HD, NP261XHD, NP263XHD



NP246, NP149

1500, 2500
NP246, NP261, NP263, NP263HD


1500, 2500

What is "pump rub"
The GM transfer cases use a gear pump inside the case that is driven off the mainshaft. The pump forces oil to the planetary as well as the drive sprocket sleeve. Because the pump is driven by the shaft, the housing of the pump must 'float' in the rear housing. There are 5 tabs around the housing that fit into spots in the rear housing to position the pump. Over time, the pump can start to wear on the rear housing. GM installed a spring steel clip in the housing intended to prevent wear but the clip can break and render useless

Being that the pump housing is aluminum and is a harder material then the magnesium rear housing, it can wear a hole in the rear housing and cause a very small leak. This leak is high enough in the case that it typically will not leak when vehicle is not moving and therefor not leaving any drops on the ground. Typically the condition is not found until there is transfer case damage from running the case out of fluid.

Avoid costly repairs to your transfer case by preventing this condition.

06-19-2014, 09:45 AM
A new truck is $55K+. The transfer case is $1500 and the truck runs great otherwise. The Duramax should last twice this mileage, so I'm told.

My truck was $69 K

It's a 2012 HD 2500 Duramax (Durajunk):o


(1) Coolant sensor on block replaced 2 Times
(2) Steering column Replace @ 15 K Miles
(3) Front Driver side strut has been replaced 4 Times
(4) Back seat panel Driver front has been replaced 3 Times , still fucked up!
(5) Drivers door panel has been replaced 2 Times , Still fucked up.
(6) Switch for sunroof light burned out at 20K Miles .
(7) Trim around front windshield had to be glue to body as at 75 MPH the chrome would make noise .
(8) Back up sensors have been replaced 4 Times, Just quit working so needs to be replaced again .
(9) I know there is more things can think of them now :cry:

I think all the newer stuff GM builds is Junk !