Been there done that. Had a spacer since 2005. Its the U joints.
Iv'e been through more parts on a 3rd gen then most people have teeth



Further...The carrier spacer will only mask the dry u joint issue until its abrupt and ugly failure....

 

My regular dealer said no problem ordered parts.Carrier bearings are on back order go figure.? He also mentioned checking drive line angle when he seen my fifth wheel hitch and asked how much weight i put on the truck.Said they would inspect rear u joints wile they had the shaft out.Is any body having trouble with their front shaft u joints??.

 

3/4 inch spacer on mine....cause I tow alot...empty.....a little shudder.....loaded smooth. U-joints two replaced one to go....If all your ujoints are new and you shudder then space your carrier bearing down appropriately. Your u-joints will last alot longer with the carrier bearing properly spaced. I replaced my carrier bearing at 160k and it made a significant reduction in shudder. I put on a Spicer perforatated unit but the best to get are the Spicer solid rubber ....like on a dump truck. It is a bearing and with out it properly supporting the shaft you will have wicked vibration on acceleration and deceleration. ks

 

Where is a good source for these aftermarket bearings. I will do mine with the U joints.

 

THIS COMMENT BROUGHT TO YOU BY... SOMEONE THAT IS ABSOLUTLY CORRECT... brop the carrier 1/2 inch amd ta da no more shudder

 

If the driveline angle isn't proper, the carrier brrg will get torn up quick. It will tend to flop around in the cage, but the one above isn't torn out. There is commonly some thin rubber spots from the mfg that tear. If the tears go into the thick part of the rubber, you have a problem.
My understanding is that the u-joints start going out on our trucks about the same time the carrier brrg does. I don't know why either. I suspect that the angle is too high and that by shimming the carrier brrg down, we may be able to get rid of the issue. I use to build custom suspensions and do axle swaps, so this was an issue that I had to pay close attention to.
Just my .02.... figuring out crap like this is close to figuring out women.

 

Dude, too much coffee, better back off some, yrou typnig si tting bad

 

Hope you have better luck then I did on getting the carrier bearing , mine was back ordered for months and then they ship the wrong one four times . Make sure you mark the drive shaft because it needs to go back together the same way . I think you have a U-joint problem more then a carrier bearing problem but with out looking at it closer it would be hard tell . Running with a bad U-joint puts a big added load on the carrier bearing and will take a lot of life out of it .

 

Dealer replaced bearing today.I think it shudders worse now than it did.They said u joints were ok.

 

Once again: There is no way to inspect for "good" u joints with the joint installed. The joint might feel fine but are dry as a bone inside.
Been there done that.

 

Take it for a drive and then climb under it and feel them if they are warm to hot it is a good sign they are bad. Some times you can see a little rust by the cap rubbers but not always . Make sure they did not install the carrier bearing out of plum with the drive line it needs to be squared up . If you have a way of lifting the truck up and running it in drive you can carefully lay your hand on the drive line and locate were the vibration is coming from which is what I did . In the end I dropped the shaft and gave the front and rear shaft a 180 % turn and all was well , you will need to remove one universal to do this . Good luck , the dealer I took my truck to was of little to no help on this same problem I hope you do better .

 

they could have left out the spacer...which would make the SHUDDER worse

 

Took it back to the dealer today.took the service manager for a ride in the lot his eyes got real big when I made the truck bounce his butt,Going back in monday he said they would have to order some after marker shims for the carrier bearing and check the drive line angle.I also ordered 3 new joints from NAPA for it at 125.00.