Has anyone had trouble with a shudder on take off. I have a GMC Sierra 2500 HD with the 6.0 gas. This shudder started approximately 400 miles after a dealer replaced the transmission. It is very pronounced when towing my 9,200 lbd trailer. I was told by dealer there is a "maybe" fix by replacing the drive shaft with a one piece. ($900.) Why replace the driveshaft if the problem was not there before the new transmission? Can anyone help? http://www.dieselplace.com/forum/smileys/Big Smile.gif Thanks, Bob

Is the "shudder" worse as more torque is applied? Does it change with vehical speed? When it stops does it stop suddenly? That fact that it happened after a tranny swap make me suspect tranny itself thay clutches my be chattering under torque load when converter is under "stall" conditions and multipling torque.

I have had it in to 2 seperate GMC dealerships they tell me it's not the tranny. ( They probably want the warranty to expire before they decide it's the problem.) Both have told me the tranny is ok and the computer showes no sign of slipping or problem. One said it was the two piece drive shaft and wanted to replace it with a one piece. It only shudders on take off and smooths out at about 15 mph. I'm thinking it might be a u-joint or carrier bearing problem?


Thanks, Bob

A carrier bearing will not cause a shudder, it usually causes a vibration. If it changes with vehical speed it could be a ujoint. If you have some on rear drive shaft running at more than 3 degrees of angle or so they can shudder under high torque load at low speeds. If you have a fairly tall axle ratio and big tires it can add to axle housing twistup and creat more than 3 degrees of angel it pinion ujoint and cause this shudder on startup.

Thanks, I'll check the angle and replace the rear joint. It's time anyway. I have 97,000 miles on the truck and I'm sure joints were not changed when the new tranny was installed 14,000 miles ago. Thanks again for your help. I'll let you know the result. Bob

Snoman, I found a broken rubber support (3 places) on the carrier bearing. Would this allow the drive line to exceed the 3 degree angle and be the cause of the shudder on take off? Bob

Snoman, I found a broken rubber support (3 places) on the carrier bearing. Would this allow the drive line to exceed the 3 degree angle and be the cause of the shudder on take off? Bob

Yes it could.

Thanks a lot. , Bob

In a word YESSSSS!!!! I'm having exactly the same problem you describe with my 6.0 gasser lemon! The problem is, mine has only 20,000 miles on it, and I've already had one tranny replaced. My truck shudders only when I first come to a complete stop and then try to accellerate fairly hard. It seems worse when I've been cruising at highway speeds for quite a while. The first tranny went at only 9700 miles, and the rest of the truck has been a real piece of sh*t. I'm taking it to the dealer for about the 8th time to have the rattling door/headliner fixed, the radio inspected (It died on a road trip recently.) and this whole shuddering problem investigated. I'd absolutely love to get rid of this thing, but it doesn't qualify under lemon law yet, and it has depreciated so much that I can't afford a new one. But what does a guy do? The warranty will be up in one more year, and then I'll really be broke....

In a word YESSSSS!!!! I'm having exactly the same problem you describe with my 6.0 gasser lemon! The problem is, mine has only 20,000 miles on it, and I've already had one tranny replaced. My truck shudders only when I first come to a complete stop and then try to accellerate fairly hard. It seems worse when I've been cruising at highway speeds for quite a while. The first tranny went at only 9700 miles, and the rest of the truck has been a real piece of sh*t. I'm taking it to the dealer for about the 8th time to have the rattling door/headliner fixed, the radio inspected (It died on a road trip recently.) and this whole shuddering problem investigated. I'd absolutely love to get rid of this thing, but it doesn't qualify under lemon law yet, and it has depreciated so much that I can't afford a new one. But what does a guy do? The warranty will be up in one more year, and then I'll really be broke....

I know they had a one piece driveshaft replacement for some trucks. On the tranny failures, most of the times short life can be traced to heat problems in tranny from improper cooling. Even the best tranny will fail if not properly cooled.

sounds like they also could of misaligned the driveshaft when they re-installed it. But if the carrier bearing is failed, that would do it too

Well - I changed all 3 u-joints, put in a new carrier bearing also replaced the rear transmission (transfer case) mount. Still shudders on take off. Seems to shudder more on a take off during a right turn uphill. I can't buy the Tec service bulletin fix about replacing the drive shaft with a one piece if the truck did not do this before the tranny change. It did not shudder for about 400 miles after the tranny change. I'm thinking it might be in the rear end. Maybe ???

sounds to me like the left side rear tranny mount, I have had similar issues with a previous truck!!

Well - I changed all 3 u-joints, put in a new carrier bearing also replaced the rear transmission (transfer case) mount. Still shudders on take off. Seems to shudder more on a take off during a right turn uphill. I can't buy the Tec service bulletin fix about replacing the drive shaft with a one piece if the truck did not do this before the tranny change. It did not shudder for about 400 miles after the tranny change. I'm thinking it might be in the rear end. Maybe ???

Makes me think it might be tranny chattering on takeoff. May be looking in wrong area. The more you crowd it, the worse it is huh?

Hi Snoman,


I gave up and traded it for an '04 8.1 extended cab long bed.


I LIKE IT!!!


Thanks to all for the advise.

Happy ending I guess. What happened to the other trucks first tranny anyway that it had to be prelaced? I am curious.

At 62,000 overheated and fried on my way to Yuma AZ pulling 8200# trailer. GMC dealer said rebuild would be as much as a replacement. I bought the truck used with 53K miles then found out it was from Canada and used on the pipeline. I think it was over-worked without much care or fluid changes. I want to thank you again for your help. I figgered it was going to start dimeing me to death. Thought I'd start new, that way I know what I've got. This 8.1 has a lot more power and I like the Allison!!!


Thanks again,


Bob

Cooking it will do it any time be it a Ally or a 4L80E make sure they have a nice big aux cooler especailly in your climate. Di old truck have a aux tranny cooler or was it just stock with no aux cooler. Yes, the 8.1 has a lot more power even at higher altitudes than a 6.0 too.

I have this problem as well. I never notice it unloaded. the tranny has been entirely rebuilt, the driveshaft balanced, the motor rebuilt, and I really noticed it pulling up steep hills pulling the trailer, but only from a standing start up to about 15 MPH. See sig for truck, cant remember if its one or two piece.

Visually check drive shaft alignment. Check the angles are equal and opposite too. If all look good it could be tranny clutch pak chatter under stall loads. Are you running a aux tranny cooler?

The first truck (GMC 6.0) had the factory tow package. I did not see an additional cooler for the tranny. The new one YES!!

The first truck (GMC 6.0) had the factory tow package. I did not see an additional cooler for the tranny. The new one YES!!

GM used to be a bit stingy about aux tranny coolers (they are getting better) and not including them with factory tow packages. When I bought my 89 4x4 burg with factory HD towing, it came with a aux engine oil cooler but not tranny. I added one soon after I got it and I still have vehical and tranny still works great after 170k.