Another broken carrier bearing

[hotdog hound]

Coming back from the last car show of the season I heard a thumping noise crawled under the truck today and she has broken another carrier bearing thats 2 in 2 years. I read the threads last year and opted for the suggested bearing from NAPA only got about 250 miles out of it. The first one was from Auto Zone and lasted 50 miles. So in reading the many posts on here for this issue seems that one piece dive shafts are not recommended. I lowered the back of truck 4 inches with lowering springs and the front 2 1/2 inches with drop spindles I got no noticeable vibration all year to suggest a out of balance drive shaft(s) any recommendations for a HD carrier bearing?
Thanks for any help

[Jason Banks]

What broke? Do you have a picture?

I had one where the spotwelds that hold the plate that is threaded to mount the bearing broke off the rest. I saw someone else post here they had the same problem. I just welded mine back together and have had no problems since.

[Jrainman]

My personal experience in muti drive shaft applications that I have had when replacing a worn carrier is that making sure the drive line is perfectly balanced ,or you will experience premature carrier wear , the only way to achieve this is to have the entire drive line balanced with the new parts by a shop that has the rite eqiument to balance the entire drive line.

most people make the mistake in when replacing the carrier not marking up the multi driveline when dismantleing , throwing the drive line out of balance when reinstalling .

driveline components do wear ,and overtime because they are multi shafts and in many cases balancing can never be achieved . I found out this from my driveline specialist ,sometimes it pays to just replace it all from end to end, in the end its worth the money and agravation to leave it to the professionals .

[Kudzupatch]

Originally Posted by hotdog hound

... I lowered the back of truck 4 inches with lowering springs and the front 2 1/2 inches with drop spindles I got no noticeable vibration all year to suggest a out of balance drive shaft(s).....

This sounds like a classic issue of the driveline not being properly set up. That the angles changed after the drop and have not been corrected. Have you checked them after dropping it?

[hotdog hound]

here is the picture hope it comes through

[old51sedan]

I just lowered mine 4 inches in the rear, was suggested that I install shims under the axles to bring the pumpkin back up into alignment where it was originally. Also recommended to install a new adjustable panhard bar if you have coils. Do a search on the subject.

[hotdog hound]

Thanks for the responses !! ned to get pictures posted there have been a lot of changes to my truck since I bought her.

[HO455]

Is this a leaf or coil spring truck? Does the rear drive shaft have a splined slider shaft?

[hotdog hound]

This is a coil spring truck with trailing arms not sure what u mean by the splined slider shaft thats a new one on me. Will have to check it out tomorrow after work thanks

[Hidesertchevy]

Slip yoke

[HO455]

Most stock 1/2 ton coil spring drive shafts are fixed length on both ends. (1st photo) The leaf spring trucks and 3/4 ton coil spring trucks have the splined slider on the rear shaft. (2nd photo bottom shaft)
When your truck's suspension moves up and down the drive shaft has to move forward and aft. A trailing arm set up has the least amount of forward and aft travel (as compared to leaf spring set ups) so GM was able to cheap out and not put a slider in the shafts. I believe the 3/4 ton torque load would be more than the 1/2 ton carriers would be able to handle.
The movement is taken up by the yoke on the transmission tail shaft. The carrier bearing is fixed to the drive shaft and the rubber mount for the bearing allows the bearing to move. If your truck is not at stock height the rubber may be maxed out at rest and then when the suspension travels it may force the carrier bearing to far and then the mount flexes until it fails. The replacement carrier bearings available today seem to have a stiffer rubber compound than the OE ones did which would add to the failure rate of the bearing mount. The 3/4 tons and leaf spring trucks have a different arrangement where the carrier bearing is fixed and the forward and aft movement is taken up in a splined section in the rear drive shaft. Thus the for and aft movement places no load on the carrier bearing.
I converted my 1/2 ton Burban to the splined slider style with an aftermarket billet to solve this problem. (3rd photo)

[72freak]

We weld every one out of the box before installing!