Shudder from the Rear

[DaveHess]

After doing a precursory search, I did not find my answer. I have a driveline shudder, and it feels like it is from the rear of the truck, but it only happens between 56 to 59 MPH and is more pronounced when towing. RPM doesn't matter, tire position doesn't matter (rotated tires to be sure) only speed matters. Nothing before 55 mph and nothing after 60 mph. I'll go so far as to say it happens almost exactly 57 to 59 mph. I figure there are only three things back there to do this; u-joint, pinion bearing or driveshaft. For the record it does not shake the truck. It is a "seat of the pants" type that you just know isn't right. Anybody else with this problem???

 

[DE Jeeper]

I'll lay odds it is a bad u-joint. How many miles do you have on them?



Aaron

 

[JDKammin]

I chased down a vibration in my truck. Replaced u-joints on rear shaft, put stock tires and wheels back on and pulled front driveshaft off. Ended up being the rear driveshaft was way out of balance. After the machine shop rebalanced the shaft, it was smooth driving. My problem did not show up til around 70 mph.

 

[HCanales]

After doing a precursory search, I did not find my answer. I have a driveline shudder, and it feels like it is from the rear of the truck, but it only happens between 56 to 59 MPH and is more pronounced when towing. RPM doesn't matter, tire position doesn't matter (rotated tires to be sure) only speed matters. Nothing before 55 mph and nothing after 60 mph. I'll go so far as to say it happens almost exactly 57 to 59 mph. I figure there are only three things back there to do this; u-joint, pinion bearing or driveshaft. For the record it does not shake the truck. It is a "seat of the pants" type that you just know isn't right. Anybody else with this problem???

I have the same problem now ever since I installed my GearVendor and I think my drive shaft is out of balance because it's been modified with new u-joints. I'd would feel good saying it's your u-joints.

 

[smitty3500]

I will say it is not U Joints. I have the same exact shudder that is also only in the seat of the pants. It is not bad and some might no notice who are use to tires worn and out of balance but I can feel it. Mine is right at 67 mph... nothing at all before it and goes away slowly as speed goes above 68.



My local tech at a dealer looked at the truck and said that no U joints looked "horrible" but did see they were dry. To try and help and get rid of this he ordered a brand new factory Drive Shaft. From the Transfer Case back with all new joints.



Sad to say it is still there. RE Roadforce Balanced all the tires and then still there! My vib is deff drivetrain related. I can travel at 67 to 70mph and put the truck in neutral and let it drift with the clutch out and the vib is 100% the same.



I am not sure the next step to take. Hoping that the cause is not the rear end or transfer case or trans I quess I will drop the front shaft and drive a short distance to rule out the front shaft. Will let you know from there.

 

[DaveHess]

After reviewing my DC Service Manual, it specifically indicates the possibility of failing U-Joints if the vibration is speed related. The truck just rolled over 50,000 miles. I think I am going to look hard at them over the winter here as this truck is a garage princess and it's going to be cold here soon... ... ...