http://www.dieselplace.com/forum/smileys/Confused.gifHas anyone experienced an abnormal vibration and load humming noises from thier drive trains?


My truck (HD2500 CC LGBD, DMAX/ALLI) started to act up recently (vibrate, shake, rattle, squeal, yes squeal!)

It is in the shop right now. Before I took it in the shop I researched on the web and found the likes of this forum looking for answers.

Along with the vibration, the truck developed a very high pitch squeal like two pieces of steel rubbing together at high speeds.

I noticed the center bearing/ bracket in the middle of the drive shaft was noticeably worn/ rusted. I shot some gear oil on it in the hopes to pin this down. The squeal disappeared for about 10 minutes.

The noise only occurs during aceleration both from a stop and during highway driving including cruise.

I told the dealer of my findings on the web and they said they will let me know what they find. Basically blew me off (can imagine what they said after they hung the phone up?)

When I spoke to the dealer later today, they said are replacing a bearing. Which one, I do not know as of yet. Hopefully this will at least end this part of the saga, but I am concerned that this may only be a temporary fix, especially if the two piece shaft is out of alignment or balance. Does anyone know if this is common occurance?

Is there any talk of GM/GMC offering or putting in one piece shafts to eliminate this problem? Is it possible to put a one piece shaft on a long truck such as this with out putting undue stress on the universals?

Is there after market kits for one piece shafts? What would this do to the Allison warranty? http://www.dieselplace.com/forum/smileys/Broken Heart.gif

There are lots of people with vibration problems. I just solved one myself which ended up being a wheel issue. I have read about problems with the 2-piece driveshafts but don't know the details. I recommend you do a search on "vibration" and or "driveshaft" and I think you willl find the info you're looking for.

boy, that sure points to a ujoint in my book.. I could be a worn center support bearing, but I am gonna put my chips on a u joint... roll pleasehttp://www.dieselplace.com/forum/smileys/Embarrased.gif

I would remove complete drive shaft and check the joints and the carrier bearing and then have it balanced at a drive shaft shop. GM is not too good about balancing them at factory and balancing is critical for smooth and quiet performance from a 2 piece drive shaft. Every GM truck I have owned has had balance issues with their driveshafts in varying degrees.

I would go with the u-joint theory. My dad had a squeal under acceleration. One of his u-joints was dry (non greasable) I will be replacing my joints with greasable ones. A preventative thing.
Welcome to the site.
Let us know in the end.

TSB # 01-04-17-001A


Replace the 2 piece drive shaft with a one piece. I've had a problem with shudder on take off forever!! I'll never buy another GM truck!!!

TSB # 01-04-17-001A


Replace the 2 piece drive shaft with a one piece. I've had a problem with shudder on take off forever!! I'll never buy another GM truck!!!

There is nothing wrong with a 2 piece drive shaft if they are done correctly. If they are not balanced correctly though, they will be prones to vibration and premature carrier bearing wear. Myself, I would never down grade from a 2 piece to a 1 piece driveshaft. I would have it properly balanced and fix the problem.

I have severe vibration in 4wd with the juice!!http://www.dieselplace.com/forum/smileys/Cry.gif And the truck pulls to the right hard on a boosted launch. I have learned to live with it, but I know it's not right.http://www.dieselplace.com/forum/smileys/Cry.gif


Jason

You are getting torque steer for chassis flex and axle wrap. In theory it should pull right from this. Not much you can do about it. Its degree will vary from vehical to vehical and the more you boost it the worse it can be. Sometimes playing with tires pressures a bit can help as well as loading some weight over the right rear tire. When you pull hard, the driveshaft torque is trying to "lift" the RR tire and it is pressing down on the LR tire cause it to bite better than RR when spinning in dirt causing it to pull right. Deeper axle gears help some too because of less torque reaction wrapup at at same tractive effort load. Edited by: snoman

Can anyone tell me where I can get a carrier bearing other than from the dealer?

My 02 crewcab dually had similar symtoms at 60,000 miles. Found that all u-joints
and hanger bearing had signs of wear. Changed all of them and its now smoth as silk
again.