I have got a low speed vib. that starts as a shudder on take off and then feels like your are driving on the rumble strip on the shoulder of the road. It also apears on decel at the same speeds( under 20 mph). Checked all the u-joints and hit all the components with a IR heat gun with no signs of exsesive heat. Tires have balance beeds also. The vib used to be on decel only after applying brakes, I assumed it was a warped rear rotor but then after a 3000 mile trip the low speed accel vib started. Any ideas would be appreciated.
Terry

 

If you have a long bed, it's your rear drivelines wobbling under load. Theres a TSB for it but I had to have the angles adjusted beyond spec by dropping the carraige bearing. DC fixed it after 7 attempts.

 

I know you said you checked the u-joints but they still may be bad. You really need to unbolt the driveshaft to check them by hand. 90% of all low speed vibration I see are from a tread seperation in a tire. Try to rotate the tires to see if it changes anything. Good luck

 

I have the same issue on my 05 (long box). Dealer dropped carrier bearing by 3/4" and shudder is gone when empty except that the driveline vibration is way worse when pulling the 5ver. Second gear shakes the truck like crazy from 1200-2100 rpm

Behrman, do you know how much they dropped the carrier bearing to fix the problem?

 

6string-about 1 inch.

 

I crawled under last night and inspected u-joints and found 2 caps missing seals. One on the diff input and one at the carrier brg.. Pickup new joints and installed tonight. Everything is great. The joint at the trans was lubed but starting to fret on one post. The rear 2 had lube in the yoke posts but the driveline posts where infected with grease worms. None the less it's fixed and it sure didn't feel like a ujoint. I can't figure way temp. gun didn't pick up a hot cap? And at that time not sign of grease worms.

gaft4, I just did the tire thing and had Schwaby trade me out of the Toyo's for Coopers. I kind feel bad now!

Thanks for the help and thanks to the guys that posted the part#'s.
Terry

 

Nice job Terry, glad to hear you found it. I've had a big pop/creak in my truck since brand new but only backing up my driveway a little to fast will make the noise. It's probably time for me to check the rear u-joints also.