bad shudder on take off from a stop

[Northerner]

Took my truck to the DC shop and went out for a ride with the service manager. It's going back in on the 7th to find out what the problem is. It shudders a bit when you start from 1st or 2nd gear when its not to hot. If it gets driven for for 50 miles or so the shudder gets much worse. Can feel it in third if you push it hard. I think it needs a new clutch. Is there anything I should watch out for with this situation. Also I can notice a bit of roughness in the clutch when I depress it. Is it possible that I have oil getting onto the clutch surface (34000 km's with all servicing done as required)

I had posted a while back when some other folks had described a shudder on take off. Right now the shudder is on left and right turns as well as straight ahead on start off from when stopped. (Hey I got the 6 speed to avoid transmission problems . . thats my luck!!) :{

 

[Gary - K7GLD]

Check U-joints and center support bearing...

 

[TCDiesel]

Several trucks have this problem,I also have it, and I upgraded my trans myself,I check drive-line and all transmission components,did not fine anything wrong. Took to dealer{ NOW OVER 3 TIMES} and they also agree their is a problem but could not find anything wrong. dealer contact rep and told me DC is working on a fix,I will give DC until this winter to fix it,This problem has existed for over 15 K. The truck had the shudder before I started doing any Mods.





I AM SURE THE IS IN THE FRONT DRIVE AXLE, AND IT WILL SHUDDER IN FORWARD OR REVERSE, IF YOU COME TO A COMPLETE STOP AND DO MOVE ADD ALL ,THAN TURN THE SHUDDER IS WORSE,IF YOU PULL ANYTHING THE SHUDDER IS MORE VIOLENT. AUTO/ MANUALS HAVE IT.



Has anyone seen a post with a 2 wheel drive having this problem.

 

[carhart32]

My 2wd has it

 

[TCDiesel]

we"ll,That shuts down my theory that it is in the front axle.

 

[Northerner]

Originally posted by Gary - KJ6Q

Check U-joints and center support bearing...

Thanks for the advice KJ6Q. I will make sure they take a look. but I'd be willing to bet its the clutch. I will make sure to post if Dealer mechanic finds the problem. Scares me if its a rear seal on the engine and oil on the clutch. Is that possible ??

 

[DIESELMAN]

There is probably nothing "wrong", just the center bearing support is out of alignment left to right. If it is consistant when starting in 1st or second, but never if you are already rolling and you nail the throttle over 25 miles an hour in any gear, I'd check the center bearing support.



It doesn't take but a fraction of an inch to be a problem.



When you start off you actually twist the axle, spring wrap. This in itself is not a problem, but it causes the pinion and center joints to be out af plane with each other. When the center bearing support is shifted to the side, it is now askew and off plane and what you feel is exactly four surges or pulses with each revoloution of the drive shaft as the tension on the drivelline increases and relaxes across the joint(s).



It seams that on the few I've seen, mine and a couple others, that the alignment is shifted to the side in the direction that turning and starting causes the most increase in vibration.



I shifted mine a 1/4 inch to the passenger side, and the vibration all but ceased. It started to come back and I again loosened and pushed it to the right, and the vibration is again gone.



This might be it, Or not, you also said you have roughness in the clutch.

 

[Northerner]

DIESELMAN Thats good info . thanks. I :-{} with my dealer today and they decided to take the truck in on Thursday. I'm going to take a printed copy of your comments to the tech so he can check it out. Its getting a lot more pronounced now. The crazy thing is it was only doing it after long trips at first and now its all the time. I guess I'll know soon enough what the problem is caused by. Still think they will find oil on the clutch hopefully not from the rear seal. I hope I'm not :{ after it goes in. .

 

[Mathew Clausen]

Mine slowly developed a shudder in 2nd and the very low end of third over the last month (24,000 miles). I was about to start investigating when it got much worse and was sqeeking under load. It was a bad u-joint (dry) at the center support. Replaced under warranty - problem solved (very smooth now - its amazing what you get used to when a problem comes slowly). FYI - before it started sqeeking badly - I had tried to pry around and find a bad u-joint but they all seemed tight. Once it was bad I was able to find the bad joint by feeling the ears after driving and one was almost too hot to touch - all others were cold.



Regarding the clutch - if it is doing this after the clutch is fully engaged - I would highly doubt it is a clutch problem. If it is while slipping the clutch - then likely.



Mathew

 

[sag2]

The center support rubber might be getting soft as it gets warm. Also there are several center support mount heights available to change the angle. If it is worse/better with a load in the bed, it is drive line angle.

This is not a new condition, many of the 1st and 2nd gen trucks have it also. It's a pretty simple fix, but you really need to verify the angles. SM has a very detailed procedure.

 

[Northerner]

Originally posted by sag2

The center support rubber might be getting soft as it gets warm. Also there are several center support mount heights available to change the angle. If it is worse/better with a load in the bed, it is drive line angle.

This is not a new condition, many of the 1st and 2nd gen trucks have it also. It's a pretty simple fix, but you really need to verify the angles. SM has a very detailed procedure.

Hey sag2 I had the truck in yesterday at the dealer and they tried to change the height with a shim. I had to drive 450 kms today and the hanger bearing is torn up good now. I parked for the week end cause I don't think I could go to much further before it rips out . There must be a procedure for lining the bearing up but I don't think the tech that will do the work on my truck will have the specs or training. Should I tell him to get the procedure first ? When I crawled under the truck I was surprised at the degree the shaft turns from the bearing back to the differential; seems extreme!! DIESLMAN you were right on but I was too late. :{

Just a note for all you folks with 6 speeds and a shudder on take off its probably the allignment on the rear drive shaft hanger bearing. ?? Saw some posts on this a while back now I understand. :{ :{