01-07 duramax junk transfer case design
 

Last week a customer brought a 04 duramax into my shop for noise coming from the T-case. We pulled the drain plug,no oil. Got approval to rxr it,was completely destroyed from lack of lube. It had a very small hole rubbed thru the bottom from the ears on the oil pump wearing there way thru the rear case half,this let all the oil leak out then it ran DRY!!!! Did some internet reaerch as this is the first one I have seen with this problem. Found a thread on the diesel page,the design of the 263xhd transfer case has 4 or 5 very thin ears of the oil pump riding on the magnesium that the rear half is made from,there is a spring steel clip that falls apart then allows the pump to wear thru the case. Once this happens the oil leaks completely out in less than a hundred miles. There were over 15,000 views on the thread,this happens on all of the 4wd duramxes sooner or later,usually between 80,000 to 150,000 miles,this one had 104,000 on it. Gm won't acknowledge there is a problem,still uses the same design today. The truck had never seen hard off road use and just normal 4wd use in the winter. Dealer gets1500$ wholesale for re-built t-case plus 300$ core that is non-refundable if it has been ran dry or has a hole in the case. I found a soucre for brand new ones for what dealer sells re-manned ones for,customer thinks hes going to find a used one,I made a few calls and was told they sell the t-cases out of wrecked ones before they even get unloaded from the wrecker at the junkyard. There is a guy in hollad,Mi who is making a pump upgrade to prevent this from happening. I have had 3 duramaxes with no problems like this but they have all been sold by 50,000 miles. This is just a heads up for anyone who has a 4wd with high miles,its alot cheaper to upgrade the pump and replace the rear 1/2 BEFORE it gets a hole in it and loses all the oil,I'll post a link if anyone needs more info,Smitty

Same thing happened on my 01 2500hd w 8100. Around 60k miles I noticed oil on the underside of truck and on my boat and trailer. Dealer replaced. I had extended warranty. Luckie me. was not a cheap fix. Then noticed again about 120K. Sold truck. And bought a new Duramax! w warranty again. So lets see some info on the upgrade. Thanks Quinlan

How can I tell which transfer case I have? I've got an '01 Yukon XL 2500 with the 8.1L/496. Guess it's time to check the fluid level and do a flush & fill.

Yeah i had the same problem with mine at 120,000, I just replaced the rear case half. Caught it before I lost all the oil and destroyed everything.

One of my tranny shops is probably doing 3-5 of these t-cases a week. The oil field has been really hard on these.

Sam

The offending transfer cases are new venture 263xhd's,ALL duramax 4wd's,even the 07's,have them and from what I know the 8.1 vehicles have them too. The pump upgrade piece is 250$ from merchant automotive 1-866-399-7169
http://www.dieselplace.com/forum/sho...d.php?t=125424
I'm not posting this thread to sell this piece so please don't delete it as I am not associated with merchant automotiive in any way,I'm posting this to save fellow duramax owners from a 1500-2200$ repair bill from running their t-cases out of oil. On a low mile vehicle the pump piece could be installed before transfer case is worn thru or has much wear with common sense and average mechaic skills,on a higher mileage vehicle plan on changing the rear t-case 1/2 ( about 300-350$)when installing the pump piece,even though it hasn't worn completely thru it will still be junk. Anyone in Mi in my area that needs this done can call the number on my signature if they need a installer,Smitty

Wipe off the tag and find the new venture designation on the back 1/2 of the t-case,it will be something like 263xhd or 246 or similar,Smitty

I wish you were closer, I wouldn't hesitate to use your services.

does this have to do with the alison transmision ?

Only on the 4 x 4 models

i have a 2007 chevy 4x4 and on the transfer case there a round silver and red tag with stamped number's the modle # for mine is ..261xhd.. is this a new modle # ? i read in previouse post modle # 263hd and 246 hd but mine is a diffrent # any input would be great
thank's
mike

Mike,the 261 xhd is the floor shift version of the hd t-case (I have never seen one) but it has the same problem,here is the part to fix it too,Smitty
http://www.gmdieseltech.com/store2/c...ategory_id=317

Thank you for the advise.

Liar Smitty, U R post'n so I will give your wife more beads!!:evilb:

Wrink,my computer room has about 400 sets of beads hanging on the wall next to my key west mile zero marker and other boating "trophys":evilb: . My mom was up here from florida last year and asked what all the beads were from,I said we go to alot of boating "festivals" where they hand them out!!!:D
Back to the t-case thread-the vendor I'm getting the new t-case from for the customer insist on having me fill it with gm synchromesh fluid,it won't stop the pump from rubbing thru but it supposedly works better than atf overall,Smitty

thank's for the info

I work in used auto parts, and I agree. These things are garbage and used ones will still run you a grand if you can find one. Ranks right up there with the piston slap GM wont acknowledge on the LS based motors.

I had to replace mine at a little over 100K. They said the front shaft was warped and caused the seal to throw all the fluid. I thought that was strange since i do not use 4 wheel except at the ramp. $3500 later I was back on the roads.

Last oil change dealer says slight tranfercase leak. 144k mi, should I have it looked at?

Depends what kind of leak,a slight leak around rear seal isn't un-common when a little rust rubs seal/slop in driveshaft yoke. On the other hand if the actual case is wet and it isn't from the rear seal then you should definately fix it before you hurt it and have to spend big bucks for a complete unit to replace it,Smitty

Thought I'd add to this very important thread.

Just went out to Merchant Automotive in Holland, MI yesterday to get my transfer case upgraded. I've had a slow leak on the top of the case for a while. I haul commercially with mine and put about 8k miles a month on it. I haven't been sleeping well as of late worrying about this whole issue. Turned out my leak was just from the rubber plug that locates a certain snap-ring. 76k on my '05 Duramax 1-ton and fortunately it had no damage yet from the pump. They installed their upgraded part and I'm back on the road with a HUGE load off my mind. :cool:

Eric Merchant is the owner of the shop. Very sharp, very good guy. He designed the upgraded part himself and his shop is the only place you can buy it. Once he had my case apart he showed me exactly what the problem is and how his part fixes it. I asked him how likely it was that mine would have started to wear, had I not fixed it and he said it's almost impossible to predict. Maybe tomorrow, mabe 6 months from now, who knows. Unfortunately, you won't know for sure until you have a hole in the case and like Smitty said, you will have a VERY short time to discover it before it kicks all the fluid out and runs the case dry.

These guys at Merchant sell at LEAST 5 of these parts a week and have replaced about 50-60 damaged cases just at their shop alone in the last 9 months or so. This certainly isn't a fluke deal and I would highly recommend getting this taken care of, if this case design is on your vehicle. I've learned that GM has used cases with this design on everything from AWD Astro vans to 1-ton trucks, since about 1998. :eek: The new style '08 trucks have a different case, but it is unknown whether they still have the same flawed internal design.

One of my neighbours is a senior tech with a GMC dealership, his specialty has been 4wd systems for a long time, he said that this transfer case issue seems to not be a problem with southern based vehicles though he was aware of it, he had not seen it.

Now that I've finally seen how the case operates and what the actual problem is, I wouldn't think that the warmer climate would make any difference. :( Maybe if the majority of your miles are highway miles and you can keep the stop and go driving to a minimum, that MIGHT help? I only say that because that's the case with my truck and at 76k I had no damage. Then again, I've heard of people with only 20-30k miles and already having it fail. I don't know. :(

I was under the impression that the problem occured in vehicles with high amounts of 4wd use, such as you get where it snows. I dont know though

Whoops, misunderstood you there! :o

It unfortunately has nothing to do with 4-wheel drive use, that's the real ***** of it all. The problem is in the upper portion of the case, so if you're driving it, it's working it.

From what I learned yesterday, the part in question is a thin plate about 6 inches or so in diameter, that basically is just a guide to keep the output shaft of the transfer case and the surrounding gears and chains and what-not, located in the correct position, as it is a completely floating assembly. The plate has I think four ears on it, which fit into matching spaces in the case housing. That's what holds it all in place. In one of the spaces there's a thin little wear clip that one of the ears kind of rides on. Since the whole assembly is moving and floating, the clip basically keeps the plate from touching the case housing.

The problem is, the factory plate is very thin and the ears have sharp edges on them. What seems to happen is the one ear will rub the clip enough to actually break it. Once the clip is gone, the ears have nothing to ride on except the actual case housng itself. So every time you are on and off the gas, the assembly is sort of moving back and forth and that plate is tapping into the case housing, now in all four spots. There just happens to be one that is a little thinner than the others on the passenger side, which is where the hole is typically showing up.

The aftermarket plate has wider ears on it which fit into the spaces on the case much better and the edges are rounded smooth, so the friction I guess is much less on the clip.

Check out the previous links in this thread from dieselplace.com. There's a lot of info and some pictures about this there. Hope this helps. :cool:

thanks for the info, I am going to print this stuff out and go see my neighbour again:drink:

Update on my end,I have fixed 3 different trucks since posting this thread,2were melted down,one was just dripping and hadn't ran out of oil yet. The problem has nothing to do with 4wd use or snow,its the oil pump ears rubbing thru the outer case once the support clip falls apart. The oil pump is rocking back and forth everytime the vehicles rear driveshaft speeds up and slows down,it turns no more or less when in 4wd. One small dealer I buy parts from has never seen one failed,a bigger dealer I buy from says they have seen "a few". This happens though after 80-90 thousand miles so it won't neccesarily be taken to the dealer as it wouldn't be under warranty,Smitty

New Venture Gear is now owned by Magna International, the Canadian Co. It used to be part of DCX.

Hopefully they will redesign the part.

Here are the applications this case is in.


http://www.drivetrain.com/transfercasesparts.html

Wannabe

Is this problem only on HD 2500 or what?? I just bought a new 2007 1500 Z71. Should I look into this problem?

HayJay,
How much does the upgrade cost? My 02 has 92k and im getting nervous. My transfer case has always been noisy when in 4 wheel drive. The noise seems to go away while accelerating or decelerating but holding at a constant speed the transfer case is very noisy. Anyone else have this problem.

Merchant sells this upgrade for 250.00, another issue is the ATF used for lubricating the case, and the amount. 5-30 synthetic engine oil is now the recommended lube, and, 2.75 qts. is the amount, necessitating the case to be filled from the speed sensor hole. There's an excellent write up on the woes of the case, easily corrected, on the diesel page, including the need for better lube. I'll agree that it's B.S. when GM knows about mortal issues, and considers them to be a fusible links to aquire work for service depts. Again though, it's not just GM........................

The part is $250 and if you have Merchant install it, will be just under $500 total, including the part. This whole upgrade thing is more of a preventative deal than a repair. If you find a hole in your case, not only will you need the upgrade but you'll need a new case half as well. A far as your noise issue, unless you have a bunch of fluid all over the bottom of your truck, my guess is you may have other problems. :confused:

I've read that too and I mentioned it to Merchant when he was working on my truck. He said he hasn't seen any reason to use oil. Just plain old ATF, filling it to the recommended level and changing it about once a year, is all that's necessary.

I've heard of lot's of people using a mix of the two, or this that and the other thing. Straight ATF for me. To each his own I guess. :D

Thought I'd bring this thread TTT.

Just lost four wheel drive on my 2500 HD, Dealer said very low on fluid, took 2 quarts, leak at rear seal. Had the truck serviced and everything was fine before I drove to Key West and back (4000 miles)

I read that this problem has no effect on 4X4, will running the transfer case low hamper the 4X4 engagement?

Thanks,

Kurt

The t-case only holds about 2 quarts, so if it needed 2, you were basically dry. With little or no fluid in the case, certainly my guess is that it would have trouble engaging in 4-wheel drive. :(

The pump rub issue is different from a rear seal leak. I had the pump upgrade done to avoid the rub problem, but I personally am still dealing with an output shaft (rear seal) leak that doesn't seem to want to go away. :rolleyes:

I've replaced my seal once now and it is still leaking from the rear somewhere. To be honest, I'm not sure if I replace the seal again if that will fix it. I may have to take it back to Merchant and see what he thinks. Again, this has nothing to do with the pump rub problem or with the upgrade that I had him install. I've heard of many people having trouble with the output shaft seal leaking on these trucks and it sounds like you and I are just part of that group.

As far as the pump rub thing goes, if the pump is rubbing the case housing, using 4-wheel drive does not help or hurt the problem. It is always rubbing as long as you are driving, 2 or 4 wheel drive. Over time, it will wear a small hole in the case and the fluid will quickly leak out and leave the case dry. From what you said it sounds like you had a leaky output shaft seal and it ran itself dry. Same ending result, it just leaked from a different spot.

Just noticed your other post, that your case is junk. Give Merchant Automotive a call. Here's their website: http://www.gmdieseltech.com/store2/

He can sell you a new case and install the pump upgrade in it as well. Don't buy one from the dealer. You'll just be right back where you started.

The chevy dealers now have a upgrade part to put in the t-cases,Idon't know what they are doing to brand new ones or ones that go up in smoke,there are several aftermarket vendors (besides merchant) out with fixes for the pump rub problem too,Smitty

Really? That's the first I've heard of that. :)

Been out since April 2007 Here you go.....





Subject: Improved Oil Fluid Wear Pump Clip - keywords 136 149 246 246EAU 261 263 263EAU housing leak case transfer transfercase #PIP4118 - (04/17/2007)



Models: 1998-2007 Light Duty Trucks and Utilities

Equipped with New Venture Gear Transfer Cases RPO NP1, NP2, NP3, NP4, NP8




--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Oil pump wear clip P/N 12470559 is broken or out of position. This may cause the pump to wear a pin hole in the transfer case rear half. If the wear is severe the transfer case may be damaged due to lack of lubrication. The clip may fatigue and break. The clip may become loose and shift out of position.

Recommendation/Instructions:
A new clip design has been released. P/N 89059653 is available for both production and service. This new part totally cancels and supersedes the former P/N 12470559. Only the new clip will be available.

This new oil pump wear clip should be used whenever a transfer case is opened for any type of internal service. See photo. GMSPO currently has inventory of the new part.





Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Nice of them to do something so quickly, isn't it? ;)

Not sure if my problem ties into this but my 05' 2500 HD Dmax had the T case go out of it back in July of 06'. Had approx 100K on it. It all started when I had the fluid change at approx 65K-70K miles. It's a fleet vehicle so it get got done at a Valvoline oil change store and got filled with Dexron III (ATF). At every oil change (5K) they would check it and it was progressivly getting dark and burnt looking. At about 80K I was getting it flushed and changed close to every other time because it was burn't so bad. Finally going up the road one day it started making a faint grinding noise. Pulled over and tried to shift it a few times into 4hi, 4lo. Wouldn't do it at first then it finally went in. No problems rest of the day. Pulled the boat that weekend no problems. Took it to GM Monday, called back and said clutch plates had let go sent metal through the whole case, it was junk. Reman $2,400 later. I looked at the owners manual and it called out for the GM synthetic. Dealer looked into it as I was hell bent on hanging this one on the Valvoline quicky shop, but they came back and said no that Dextron III was approved. Then why would the manual call out for synthetic, WTF? I kind of just let it go since it didn't come out of my pocket. I'm starting to wonder now if the metal wasn't the tabs breaking off the oil pump wear clip?
Drove it another 50 K and got the same truck 07' (classic). 76K so far and no prob. I had GM change the fluid at 50K this time and made sure they put synthetic in.
Since this truck has a 100K powertrain warranty on it will GM go ahead and install their the new oil pump wear climp under warranty even though I'm not having any problems yet?