launch shudder still there...help!!!!!

[mr plow]

well, today, they replaced the transmission,and the launch shudder is still there. Previously, i had the driveshaft hangar replaced, and the driveshaft balanced, all to no avail. we are stumped. The prevailing thought is that the driveshaft hangar is too flimsy for that much torque, and is allowing the shimmy.



btw, the shimmy only occurs at launch between 10-20km/hr or 6-12 mph, then dissappears. if i launch really slow, almost no shudder.



any help would be appreciated.





thanks in advance.





Oren.

 

[TBOB]

shudder

If you tow a trailer take it to the Dodge dealer and have the tech watch the diff as you set the trailer brakes and try to move the rig. The diff will rotate up in front causing an acute angle at the u joint. Try having them use degree shims as needed to help lower the front of the pinion. TBOB

 

[mr plow]

been there done that.

but thank you very much.



next... .

 

[Summit]

mr plow, i have the exact same prob. acts like my 01 did with a lift kit and they didnt shim the carrier bearing on the drive shaft, it too only did it on takeoff but gets lots worse the bigger the load is.

 

[mr plow]

seems to me that the only cure would be

a one piece driveshaft.

 

[nickleinonen]

the boys [and girls] over on the dieselpage forums have had problems with launch shutter and gm's solution for it was a 1 piece aluminum driveshaft. it works well they say, as long as the dealer knew what they were doing. gm dealers destroyed many trucks sadly. they cut the entire crossmember off instead of just the carrier bracket. that comprimized the frames strength and there are a few cases where insurance companies sent nearly new trucks to the car crusher to destroy the truck. others had new frames installed, and i'll bet there are many trucks on the road that had the 1 pc shaft installed that have the cross member removed, and the driver knows nothing is wrong

 

[JDalton]

I have the same problem on a #oyota Tundra. It has a split drive shaft and has launch shutter as well as driveline vibration between 50 and 60 MPH. My son has a 2500 Chevy HD with the same problems. I think it is just the nature of a two piece drive shaft.

 

[Blair]

The drive line angles on a 1 piece shaft have to be exactly the same at both ends or you will get shudder. When launching the axle wrap changes the angle at the pinion causing shudder as well. Oddly enough a 2 piece drive shaft is suppose to be less susceptible to drive line shudder. Repairs for this include angle shims for the rear diff and shimming the steady bearing.



We had a customer where we had to put his 5th wheel on his truck and his truck on the dyno to find his drive line vibration and it turned out to be worn out a transmission mount allowing the drive line angle to change only when loaded and launching.



We run into this issue when install Gear vendor units as well.



In Chryslers infinite wisdom they at one time had us putting hose clamps on brand new Jeep Grand Cherokees to balance the drive shafts.

 

[CumminsPower98]

I am having the same problems on my '98 12 valve that I put a 6-speed in. The strange thing is that I did this same job to a '98 12 valve 3500 and it did not have the problem at all. My cousin did the same thing with his '97 and no trouble so I can't figure why I am having driveline angle problems. I raised the back end of the trany 3/8" and that cut the shudder about in half. I tried different heights and 3/8" is about the best but still not fully curred. This stuff sure can be touchy sometimes and hope some day I get mine figured out.



Mark