Mutt68

I am getting a bad vibration at part to light throttle. Very noticable driving through the neighborhood and very light throttle.....or just maintaining speed on the highway with very light throttle. Under harder excelleration from a stop to get up to speed or passing on the highway it is less noticable. Vey noticable at light throttle at all speeds. When you let off and coast she is smooth as can be....apple a little throttle and vibration again. Any ideas??? The truck configuation is below in my signature....and I have 81K miles on her.

Scubanero

Sounds like a U joint to me.

trik396

Just had the EXACT same issue. I searched high and low trying to find out what it could be... and it couldn't be my u-joints because I had just installed new greaseable ones less than a year ago and greased them every 4 months... and it turned out to be... Ready?

U-JOINTS...

WilderMike

Mutt68 -
I've got the exact same thing going on here, driving me nuts! What did you come up with? My u-joints appear to be fine....92K on them but seem to be fine.
Thanks,
mike

shima

Another sign of ujoints is if it chirps in reverse. Mine did and I had vibration. At 85K miles, I changed the ujoints and the problems went away. Good luck to you.

Sent from my MB860 using Tapatalk

torquefan

I would focus on the rear driveshaft for that type of complaint, and if you don't feel any play in the joints with the truck in neutral and the emer. brake on, you'll need to remove the shaft and flex each joint both ways and feel for one that is seized. You'll never be able to feel a seized joint while the shaft is still mounted in the truck.

jhenson

Sounds much like a u-joint problem. My truck only had 30k on it when all 3 joints on the rear shaft were completely siezed. Disconnected the shaft at the rear diff and it just stayed there.....really had to pull on it just to make it move down. Dealership showed me the joints and I have never seen anything like that before.....needles were almost melted together....then at 200k I had to replace front axle joints.....same thing....nothing but red powder and mutilated needles fell out of the caps.

DodgeChallenger

Sounds like U-Joints. Mine are heading that way. Heard good and bad about greasable units. If you reassemble with a hammer then there could be problems. I have always pressed mine back in with a large vise works well. Nice and gentle install.

Scubanero - I like your footer statement Binary 10 = 2

dogman

I had the same problem with just about the same symptoms. Took it in to my (non-dealer) mechanic and after a road test and a look see on the lift they determined it to be a bad center u-joint rear shaft. Had it replaced this morning but much to my disappointment all the way home I had just about the same vibration I had to begin with. So, with a few hundred bucks less in my pocket, it's back to the drawing board. The vibration is still greatest at low speeds and can be felt on the floor and through the steering wheel although the steering wheel is rock solid as far as any shimmy goes. What else could it be? Any ideas would be greatly appreciated.

smartin1

Just went through this also. But I had 150k miles. Replaced the 3 u joints on the front shaft, still had the vibration. Had done the ball joints and wheel joints last year. Then replaced the 3 rear u joints. The center u joint was rusted and nearly froze up. But the real issue was the carrier bearing. It was nearly frozen up. It can not be lubricated. While the rear drive shaft is out, you must replace the carrier bearing. Its essential. But don't pay $200 for the dealer bearing. NAPA has it and I found the part # on this forum. Its NAPA bearing HB88508 and I paid $67.49 for it. NAPA counter said they couldn't get the carrier bearing. Give them the part # and they'll have it. So now I have all 6 drive shaft bearings with grease fittings and a new carrier bearing. Should be good for 100k-150k miles hopefully. If you lose a new u joint prematurely, its because of bad install or a cheap bearing. Pay up for good u joints, and use a bearing press or vice. The vibration was making me crazy till I got it solved. Good luck.

papaduck

I'm not saying that it is not a u-joint, but check the harmonic balancer on the front of the crank shaft. It is supposed to be checked every 30k miles. Check for the rubber splitting and seperating and make sure the 2 marks are opposite each other and aligned on the inner and outer steel parts.

DodgeChallenger

Dogman - all the u-joints travel the same amount so I cannot understand why the dealer only replaced one unless it was warranty. Then they only replace what they feel is the problem. When I do mine it is all of them at the same time. Front and rear shafts.

WilderMike

Well guys, I found it! It ended up being the rear joint at the rear axle! Swear to God I replaced it a year ago with a Spicer greaseable unit and assumed it was fine. Goes to show you can't really tell until you remove everything and check first hand. Whatta pisser! My plan is change out ALL the ujoints this week due to the mileage. I'm gonna try the precision HD greaseables, have had good luck with them at work so we'll see.

papaduck

Glad you found it and that it was not something more expensive.

smartin1

By all means replace that carrier bearing while you have the rear shaft down. You'll never regret it. Good luck.