Hello. I am new here. I have a 2003 2500 Hd with Duramax, 57000 miles. Just started feeling a rumble/shake under drivers feet at speeds of 45-50. The shake is not constant and seems to occur in 5th gear and will continue while sloiwing Local mechanic states probably u-joint. Any suggestions? Thanks

Subject: Suspension Vibration or Frame Beaming at 40-60 MPH - keywords chuggle rear shake shock spring TCC tire #PIT3009C - (06/28/2006)



Models: 1999-2007 Chevrolet Silverado Classic

1999-2007 GMC Sierra Classic




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This PI is being updated to add 2007 model and to advise that no more FPR are needed. Please discard PIT3009B.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Beam shake vibration is usually felt in the seat and occurring between 40-50 mph. Hertz readings using an EVA tool are normally between 8-24 Hz. This condition is most common on extended cab and crew cab (http://www.dieselplace.com/forum/autolink.php?id=29&script=showthread&forumid=80) models but has also been noted in other models.

Recommendation/Instructions:
The severity of beam shake may vary from vehicle to vehicle. To determine if the concern is beam shake, please perform the following:

Test drive vehicle to confirm the condition. A beam shake condition will usually respond to concrete type pavements more than asphalt, so the vehicle should be driven over both surfaces if possible.
Place 200-500 pounds in the pickup bed between the closed tailgate and the wheel wells. A beaming condition should dissipate.
If the concern is determined to be beam shake, this is a characteristic of the vehicle and currently no repair attempts should be made. With your help in the use of the Field Product Reporting process GM Engineering is currently developing a enhancement to the body mounts to reduce this concern on the 1500 Models and should be available shortly. There will be no enhancement made to the 2500 and 3500 models. At this point no more Field Product Reports are needed and Thanks for your help.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

I should mention the truck is a crew cab with 4wd. The problem has only been noticed in 2wd and it does not do it all the time.

Mine started the same way. Only around 45-55 MPH then over time started to happen more at lower speeds. Now is noticeable at all speeds but not as much over 55 mph. I have replaced tires, shocks, front aux spring/bump stops, alignment and adjusted cab mount bolts with no resolution. Althought the shocks lessened the bumps. New spicer life 5-801x ujoints were ordered today and hope to get them on Monday or Tuesday. I will let you know if it changes. I may also while it is out check the balance on the driveshaft and inspect and lube if necessary the slip yoke splines. While I am sure the TSB problem listed earlier is real for some, my truck did not always do this so I have a hard time believing this is systemic to the design of the frame, but only time will tell.

Located problem. The 35.5 mm locking nut on the drivers side wheel bearing assembly was loose. Nut backed off 180 degrees causing the tire to become loose and shake. U-joints were fine.