I have been chasing a vibration that slowly developed on my truck for 70,000 miles now (about 3 years, I now have 107K). After 3 sets of wheels and tires, countless balancing jobs, and a lot of aggrevation, It is finally fixed...

The culprit was the drive shaft was slightly out of balance...ever so slightly. After checking EVERY thing else on the truck, I finally took it in to a drive line shop. 30 minutes later...no vibration!!!

I know a lot of people have been chasing vibrations on their trucks...If you cannot figure out what is causing it, do yourself a favor and take your shaft to a good driveline shop, pay the $35, and have it balanced. The shaft was out very little (mostly due to Corrosion, steel shaft), but was out enough to cause havoc driving down the road at speeds greater than 40mph.

I also learned some other interesting things talking with the owner of the shop. If you change your U-Joints, you should have your shaft balanced. A slight difference in weight (due to manufacturing) on the joints can throw your shaft off enough to cause a vibration. He also said that he sees shafts out of these new, high torque diesel trucks, get out of balance much more than the gassers do due to the torque applied over time. It is not enough to see with the eye, but will be felt on the road over time.

He also told me that the new aluminum shafts fail at a rate of 5 to 1 when compaired to a steel shaft. There were a couple aluminum shafts twisted right in half laying on the counter there. (Not saying this going to happen to you, just thought it was interesting)

Now, before I went to the shop to balance the shaft, I had replaced the factory u-joints 2 weeks before. (Turns out the factory joints were still good!) DO NOT USE NAPA U-JOINTS! Attached are a couple of pictures of the NAPA joints after 2 weeks and 150 miles! Yes, they were fully greased upon install. The drive line shop replaced the NAPA joints with Spicers before balancing. All is good now.:D

Hope this helps at least one person with a vibration issue.

That is from just sitting for a prolong time, it was like that upon installation probably, I don't know for sure.

Me and a friend were doing a stroker kit in my BRAND NEW Harley Davidson, only had 15 miles on it, and the bearing races on the rods journals looked just like that, I took it in to the HD Dealer, and they said that I should ride it more often and not let it sit. I told him I rode the bike home, 5 miles, and tore the engine down and this is what I found. I said that they need to crank the bikes more often, and at least let the oil flow throu it and not try to blame it on me. I was rebuiding it anyway, so it did not matter, but the look on their faces was worth it. Just my bearing story, BTW the Harleys have a roller bearing rod and main bearings, before someone says they should be the bearing inserts.

(QUOTE).....DO NOT USE NAPA U-JOINTS!


We use napa u-joint in all of our semis on the farm and never had a problem or concern with them. I just installed a rear u-joint on my truck today.

I have been chasing vibrations and tomorrow morning the truck is going in for a failed tranny mount, bad carrier bearing and 3 u joints, and of course balancing, oh yeah the tail shaft seal on the tranny was leaking as well due to the bad drive-shaft.
The next project(when the funds are available:( ) will be the rear-end being rebuilt due to me putting the other issues listed above off too long:mad: .
As bagofdimes stated, check your stuff before it causes a more extensive problem as I ran into.;)

Mark:beerchug:

And in addition, the u joints and carrier bearing "WILL" be Spicers.:D

Mark:beerchug: