Transfer Case Explosion

[Erimikos]

Well, the purpose of this post has changed just a bit.

I was going to explain that I took the truck for a ride and heard some noises from underneath the truck, and I was also going to say that I had changed the ATF fluid in the tranny, as the first thought was that it sounded dry for some reason. I hadnt seen any leaks, but just got the truck about 20K ago, and not sure of its history.

However, after buying the ATF, I got out my tools and crawled under the truck to flush the transfer case, and very quickly found the source of my problem.

An approximately 4 inch wide, 1 inch tall hole in the back of my transfer case! Ok, so just maybe fresh fluid won't fix that. My thing is, I don't know why the hole is there! I wasn't hard on the transfer case, and didn't hear any real noises coming from it. It has always been rather smooth shifting into 4 when I used it.. .

Anyway, does anyone have any idea what would cause the side of the transmission to blow out like that? It looks like a clean break for most of it, except a small part that looks somewhat shredded. An exploding bearing maybe?

Any recommendations on whether the transfer case itself can be fixed with a new cover on the back, or where I can get one for a decent price? GM price at the moment is about 1700, although I can get one for about 1450 at GM parts direct...

I am open to used, but its rough to find replacements as far as I can tell. Too new to be in the junkyards, and as far as I can tell, not something that fails often on these trucks, so not a big aftermarket for them..

Anyway, forgot the little details. Its an 03 2500HD Crew Cab Long Bed 4x4 with the 6.6 Duramax/Allison combo. Not sure which LLX designation that makes it...

 

[RobsDmax]

welcome. your truck has suffered pump rub and it is common on all dmaxes up to the 07.5 LMM. your truck is a LB7 and check out merchant automotive for a half case and pump rub plate

 

[Erimikos]

I am not sure that a new rear half of the case and pump plates from Merchant will take care of it... but thats from looking at the outside of the T-case, and I admittedly know little about them. What do you guys think?

It wasn't driven long while making any noise, maybe 10 miles total in a couple short trips but looking at the transfer case, I cant see how it wasn't making any noise for a while. Take a look.

It seems like more then just a pump rub to me. More like a pump rub causing a gear to explode.. Thing is, even the way it is at the moment, it still runs fairly quiet and works well considering how it looks. Looking like that I would expect all sorts of grinding and clunking, if anything at all..

 

[Hot COCOAL]

it was pump rub, now it has escalated into something much worse,pump rub is know as the silent killer, you would be lucky to see the leak and it doesnt make a noise until it is way too late. i wouldnt be suprised if you need a complete rebuild, and from the looks of it, that is the only route i would consider...make sure to add a pump rub kit when it goes back together, merchant, ppe(ppe branded merchant part) and sonnex are suppliers that come to mind.

good luck, im not sure i would keep driving it, unless its going to the shop

 

[dirty_max]

wow that one is bad

 

[Erimikos]

it was pump rub, now it has escalated into something much worse,pump rub is know as the silent killer, you would be lucky to see the leak and it doesnt make a noise until it is way too late. i wouldnt be suprised if you need a complete rebuild, and from the looks of it, that is the only route i would consider...make sure to add a pump rub kit when it goes back together, merchant, ppe(ppe branded merchant part) and sonnex are suppliers that come to mind.

good luck, im not sure i would keep driving it, unless its going to the shop

That's about where I am at the moment. The truck isn't leaving the driveway unless its to go get a replacement transfer case. (dont want to put that in the Mustang if I can avoid it. lol)

I know I probably could get away with driving it a little bit, I mean seriously, whats the worst that I can do, break the transfer case? Somehow not certain that I care that much about that aspect at the moment. However, I AM more concerned with the tow bill when I can't get it home if it truly eats itself.

 

[Erimikos]

Does anyone know if this issue has been fixed if I end up with a new Transfer case from Chevy, or will I need to tear into that one as soon as I get it, if that's the route I go, to perform the upgrade?

And if thats the case, are there any other recommended upgrades/fixes for the transfer case while its already apart? I didn't really see anything, but wanted to ask.

 

[blk smoke lb7]

You need the pump rub fit from Merchant and will have to split the case to install.Some comoanys sell a replacemnt t case with the pump rub kit installed but they want your case sent back for core bad thing is you case is messed up and it may have started to get inti the shafts and there may not be much good left in there and you will have paid to send the old case back in to have them tell you they are going to not refund your core money and if you want the old case back your going to have to pay for return shipping.Better to find a used 1 close to you and split it install the pump rub kit and install.

 

[Dozerboy]

I agree with the above find a used one.

On a side note damn thats ugly I didn't know they would go that long.

 

[Erimikos]

Honestly, even though mine somewhat exploded, the fact that it did go so long actually makes me think more of that T-case.

I got it about 20K miles ago, and had never seen any sign of a spill under the truck. That makes me actually wonder just how long that hole has been there, and realistically, to run for any length of time without lubricant is pretty impressive, let alone if it had been the 3K miles, and a good deal of use thanks to some pretty impressive snowfalls since my last long trip or more!

Anyway, I managed to find one from a guy on Ebay in Louisiana for about 1300 with free shipping, so thats on its way. Now I just need to find a place to try and get it done Tuesday if it gets here in time. The thing wont fit in my garage, and I am not convinced I can move enough stuff to get it in my barn..

 

[BlkMax]

There are cheaper pump rub fixes than the one from Merchant and will work just as well. It is a steel plate that drops into the pockets the pump indexes into in the rear case half. About $30 for the shim and some silicone sealant and you are good to go. If you have it a little trans assembly gel will hold the steal plate in place as you are putting the case halves back together.

It might be worth asking the Ebay guy if it has the pump rub fix, or you may be doing it again. These cases are magnesium, so any rubbing at all will eat through the material, but it does make them light.

 

[Erimikos]

There are cheaper pump rub fixes than the one from Merchant and will work just as well. It is a steel plate that drops into the pockets the pump indexes into in the rear case half. About $30 for the shim and some silicone sealant and you are good to go. If you have it a little trans assembly gel will hold the steal plate in place as you are putting the case halves back together.

It might be worth asking the Ebay guy if it has the pump rub fix, or you may be doing it again. These cases are magnesium, so any rubbing at all will eat through the material, but it does make them light.

Yep, I gave the guy a call and he loved to talk, but the transfer case is a fresh rebuild he did at his transmission shop. He was aware of the problem, and does install the fix on all the 263XHD transfer cases he rebuilds. The listing had a picture of the fix in place. Also has a 1 year unlimited mile warranty on the transfer case, so should be good to go.

That kit was one of my concerns. I didn't want to end up having to have the dealer replace the T-Case only to have to pull it back off again and tear it apart to install the fix!

Thanks for all the suggestions! I appreciate it.

 

[Erimikos]

Alright, I have a couple quick questions, as I am far from a mechanic. I have done a good deal of work on cars in the past, but have managed to avoid driveline work somehow in the past... I am working on replacing my transfer case, and have disconnected the front driveshaft from the axle, and am about to disconnect the rear. Admittedly, I havent gotten far yet, but I should be able to once I figure tihs part out.

Where the front driveshaft connects to the T-Case, there is a rubber boot with metal clamps over it. From what I have seen, I need to cut that clamp before I can pull the driveshaft from the T-Case. The clamp however is in a groove in the boot so I am not sure of a good way to cut it without cutting the boot... Also, when replacing the driveshaft in the new one, should I just stick a hose clamp over that part, or would I need to stick one there, and another next to it with the screw on the opposite side of the boot to fix any balance issues?


For the rear drive shaft, if I am understanding the directions correctly I unbolt the u-joint from the rear axle, and then I can slide the driveshaft back and out. I assume I have to drop the U shaped bracket holding the driveshaft to the truck as well as its a 2 peice driveshaft in order to slide it backwards and out of the T-Case? I ask before just dropping it because as it is holding the driveshaft, I don't know what it has in place regarding lubrication or bearings, and I don't want to unnecessarily open yet another can of worms.

Just being cautious on this one as I dont want to make things any harder then they need to be.

Thanks for any tips!

 

[Dozerboy]

You can slide the boot off the front shaft pry it back away from the case if I remember right.

 

[Erimikos]

Yep, I got them off tonight and sitting in the garage. I would have gotten further but alas, light and temperatures ran out on me.

Thanks for all the help!