Looking for ideas as I seem to be stumped...


I have searched and read may posts on the vibration at 40-50 mph. My vibration occurs between 38-48 and again between 65-70.


Things I have already done:
New ball joints and new right hub approx 3 years and 25k ago
This year:
Serviced both hubs, new front brake pads and turned rotors, serviced 4x4 autolock hubs (Sept)
New Tires & rims- issue was there with old tires as well (Oct)
Replaced ujoints and carrier bearing, had drive shaft balanced at same time (yesterday)


The vibration continues... I was pretty sure the ujoints and or carrier bearing would fix it...


The tire shop says front end is tight, shocks are in need of replacement but not leaking. Not sure where else to look?

Thanks,
Wink

 

I'm right there with you. I have a 40-ish mph and 70-ish mph vibration myself.
I've recently replaced the rear tires, balanced the front's, replaced the U-joints and carrier bearing, front wheel bearings, etc....
Balancing the drive shaft was my next step, but I see it didn't help you
Did the shop comment on the condition of the vibration ring on the rear of the shaft? was the rubber dry rotted?

I have read some info about the harmonic balancer causing similar issues, so that may be another thing to look at.

 

They took it off, said it was not necessary after they balanced both shafts. The vibration is not terrible, but didn't used to be there. It may be that it is not a huge issue but for piece of mind I would really like to narrow this down.... Driving me nuts....

 

Do you have a lift?

 

Crawl under your truck at the rear differential. Push up/down and left/right on the pinion where the drive shaft connects to the pinion. Do you have play? If so then how much? Are you leaking differential fluid from the rear? I know that you should have caught this when you did the ujoints but it is worth checking.
Dwayne

 

Nope stock

 

No leaks and no play in the pinion while in park, should it be checked in neutral?

 

If it's sitting on level ground without a bind holding the truck from rolling, I would chock the wheels and check it in neutral.
Another thing to try is to bump the truck into neutral while doing 40mph or when your feeling the vibration to eliminate the engine/harmonic balancer as the source. (mine keeps vibrating )

 

Frank - Dwayne,

The play was in the pinion yoke. Once I took the bind off there was side to side play. Appearantly the ears that hold the u joint have gotten worn. The expert at the machine shop had a trick to save replacing the pinion for now, he put a small shim under each cap which removed the play and presto vibration gone! I will replace the pinion yoke/shaft but what a relief to know the reason!

Hope this helps someone else with all of the vibration issues out there...

Many thanks!
Wink

 

Thanks for posting this Wink, I'll have to give my pinion a shake down

 

Glad you found your problem.

For future reference, one technique I like to use for finding loose driveline parts is this: Put the truck in Park, with the parking brake off. Lay under the truck and put one foot against one of the rear tires and start pushing it, so you get it rocking back and forth against the Park pawl. By doing this you can use the weight of the truck to load and unload the driveline, in both directions, and sometimes clunks and loose parts show themselves.

 

Wink I am glad you found it ! But I am a little unclear what you mean or how he put a shim under the cap? Did he take the needle bearings out and put a shim the size of the cap in or did he use a small shim that fit inside the cap and needle bearings?

 

It was a small and fit inside the cap and bearings, tucked in in there with his pinky finger, not sure the thickness. I need to call him and get a bit more info on what the shim dimensions were. approx 1/8 to 3/16 sqaure but not sure how thick?

 

I would think that he took the loops off of the yoke one at a time, and put a shim between the u-joint and the cup. Not inside the cups. That's what I took away from it.