Grinding noise -2500HD/DMax/Allison - PLEASE help!

dbm76 · November 20, 2002

Wow this is really frightening... as the title suggests, I'm driving a GMC 2500HD with the duramax and Allison tranny. Brand new truck, dealer plates still, about 3200 miles. Never towed anything with it.

Today I took it to the store, and when I started driving out of the parkign lot I heard this "scraping" sound almost like I was dragging something under the car or had the fender liner rubbing a tire. So I stop and check. Nothing.

Try driving a little more and it is scraping/grinding BAD. Enough that it makes the truck feel like it's being dragged down, and when I let my foot off the gas it STOPS. So I left it where it is, have a flatbed coming for it in the morning.

I know the obvious question - the parking brake is released, I tried setting and releasing it several times to make sure; it springs out just like I would expect it to, and I in fact rarely park it with the brake set, so I can't see it getting stuck in the engaged position.

I had my wife drive the truck slowly past me and tried to localize the sound - it does not seem to be coming from any corner, but more from the center of the truck. Sounds the same whether in 2WD / 4H / 4L. I couldn't get a feeling for whether it made the noise in neutral when rolling (which would have helped a lot). The engine revs freely in neutral though, and there is nothing obviously amiss in the engine bay or in the visible portion of the driveline.

Does anyone have ANY clue what might be going on? This truck has not seen any sort of excessive duty, and I am confident whatever happened will be covered by the warrantee, but I'd like to know a little before I see what the dealer has to say tomorrow.

Thanks for any assistance!

BDBWTE · November 20, 2002

Tuffy....what is the temperature where you are at??? the only reason I ask is because sometimes those d@mn E-Brakes can freeze up on your rotors pretty fast it's happened..but you putting the truck in reverse should have poped it out...

Ahh

You check the tranny fluid??? maybe not enough line persure in the tranny to shift properly or the converter isn't working properly....even then holding a 300hp/520lbs/ft torque diesel back is negligible...

My buddy's DMAX had a problem where the caliper on his rear brake actually locked themselves and stayed locked....unfortunate for him he was going down the road and spun his truck a couple times... managed to break the rotors... GM replaced everything....maybe of some help....

Asides that man I really don't know...but I do know that I would absolutely insist on not only GM finding the problem but if in deed it's major replacing the truck and lemon law it...3,000 miles that's a joke nothing is even close to being broken in yet...

dbm76 · November 20, 2002

Well, got the car towed in today, we'll see what the dealer says. They don't have a Diesel / Allison mechanic on site so looks like they'll be towing it to the Chevy dealer down the road where they do commercial truck work.

One thing I noticed - when I put the transfer case in neutral and the shift lever in drive (as the manual says to do for one second when preparing to tow) it makes a really bad rattling/clattering noise. I have never disengaged the xfer case before so I wasn't sure if this was normal. Any thoughts?

Oh and the weather here in so cal is supposed to be 87 degrees today (happy thanksgiving!) so I don't think it's a freezing issue.

dbm76 · November 21, 2002

For anyone interested, the problem was located at the dealership today - transfer case is SHOT. 3500 miles. Only used 4wd for possibly 30 feet of driving on one occasion.

Apparently the transfer case on the 2003 models is different from that on the earlier ones, so everyone buying or considering a purchase should probably be aware. I'm sure if this is a persistent problem we'll be hearing more about it. Hopefully this was just an isolated incident.

Dealer is overnighting a new xfer case from Michigan, should be fixed by tomorrow evening, but the fact that something like this happened while the dealer plates were still on the car is so far beyond acceptable Quality Control that it will probably permanently color my perception of GM trucks. It was fortunate that this happened within about 5 miles of my home, in a parking lot, where it didn't cause any dangerous or terribly inconvenient conditions, or I would be a LOT more irritated right now.

Shaners · November 21, 2002

For anyone interested, the problem was located at the dealership today - transfer case is SHOT. 3500 miles. Only used 4wd for possibly 30 feet of driving on one occasion.

Apparently the transfer case on the 2003 models is different from that on the earlier ones, so everyone buying or considering a purchase should probably be aware. I'm sure if this is a persistent problem we'll be hearing more about it. Hopefully this was just an isolated incident.

Dealer is overnighting a new xfer case from Michigan, should be fixed by tomorrow evening, but the fact that something like this happened while the dealer plates were still on the car is so far beyond acceptable Quality Control that it will probably permanently color my perception of GM trucks. It was fortunate that this happened within about 5 miles of my home, in a parking lot, where it didn't cause any dangerous or terribly inconvenient conditions, or I would be a LOT more irritated right now.

Just so you don't feel alone on this, I had to have the tansfer case replaced on my '01 at about the same milage...

BDBWTE · November 21, 2002

For anyone interested, the problem was located at the dealership today - transfer case is SHOT. 3500 miles. Only used 4wd for possibly 30 feet of driving on one occasion.

Apparently the transfer case on the 2003 models is different from that on the earlier ones, so everyone buying or considering a purchase should probably be aware. I'm sure if this is a persistent problem we'll be hearing more about it. Hopefully this was just an isolated incident.

Dealer is overnighting a new xfer case from Michigan, should be fixed by tomorrow evening, but the fact that something like this happened while the dealer plates were still on the car is so far beyond acceptable Quality Control that it will probably permanently color my perception of GM trucks. It was fortunate that this happened within about 5 miles of my home, in a parking lot, where it didn't cause any dangerous or terribly inconvenient conditions, or I would be a LOT more irritated right now.

NP forgot to pack a grease packing in my 1/2 Silverado and I had to have mine replaced...