amercier4

Hi All,
I just changed the middle u-joint on my driveshaft due to vibration that developed over last weekend. (I know should change both, but I'm doing what I can). That seemed to fix the vibration that I was getting. No doubt the cause as that u-joint was definitely bad.

However, now I have an almost constant low-level vibration in the drivetrain. I'm guessing that maybe I didn't put the driveshaft back in properly. I did mark the shaft parts as it came out and believe I put it all back in correctly, but maybe not. Would putting the shaft back in the wrong position result in this type of vibration?


Thanks
Al

15 Digger

On a 2 piece driveshaft with a slip joint you have to mark it and put it back together right. If its out of phase it can vibrate. Try to align the joints.

CamperAndy

Possible and there was a recent post where the transmission tail shaft housing failed due to this type of issue. You may want to pull it all apart again and recheck everything.

amercier4

Yeah, that is what I was afraid of. I know I marked it and thought I had it back together right. How small of a tolerance is there? Are we talking one tooth off as being enough to cause this?

Dartsport

YES, 1 tooth off is enough to cause a vibration......

Chip

Since you have a long bed, I'm assuming you have a 2 piece drive shaft. Did you check the carrier bearing. What about the other 2 u-joints, are they in good shape? There is a pricey quick-fix to your drive shaft issues. Some of the members on this forum have switched to a 1 piece drive shaft. If your'e not familiar with the 1 piece shaft, check out www.doghousediesel.com. You can have just 2 ujoints and no carrier bearing for somewhere around $550.00 and most if not all of your driveline vibrations eliminated.

amercier4

Thanks Chip. I have seen the posts about the 1 piece drive shaft. I like the idea, but can't afford it at this time. I did double check the alignment and best I can tell it seems to be right. All marks line up. Hard to tell if 1 tooth off one way or the other though. Plus, the other 2 u-joints seem okay. Rear one at the rear pinion has been replaced and was free and smooth when I had the driveshaft out, thats why I didn't replace it. Front one seems fine too.

What I did find is that one set of the cups on the new u-joint were not pressed together all the way. I could take the yoke of the u-joint and move back and forth... maybe 2-3 millimeters. I used the old hammer and socket routine and sat the cups until no more play. Took a quick drive and seemed okay. I am going to test drive to work tomorrow and see what that did.

If there is still a vibration, I will spend Saturday morning pulling driveshaft down and trying to adjust. At that point, I'll look more into maybe changing out the other 2 u-joints while I'm at it.

Any advice on how to check the carrier bearing? I'm good with u-joints (done enough of them on this truck), but never had the misfortune for the carrier bearing before.

Thanks

Chip

My experience with mine was I laid on my back right under the bearing and with both hands tried to move it up and down. I had about 3/8 to 1/2 inch of up and down play in mine. What a design flaw. Mine also would clunk when taking off from a dead stop, like sitting at a traffic light. I ordered a new carrier and 3 new u-joints untill I found out about this 1 piece drive shaft. I had almost $380.00 into parts. I opted to return all the parts and get the 1 piece so I would never have to worry about that rediculous carrier and 1 less u-joint. I've seen those carrier bearings last 100k miles and I've seen them last 30k miles. More than likely if you do have to replace the carrier bearing, you may have to take it to a driveline shop to have the old one pressed off and a new one pressed on.