well my moms truck has a vibration that i cant figure out...its an 03 250hp 2500 quad cab long box 4x4 with leveling kit and 285's.. it had bad vibrations on accelerations so i changed all rear u joints and steady bearing that fixed the big vibration..she had it taken to a shop while i was at work and he thought it was a front axle u joint so he changed that and its still there..its just a small vibration that you can feel while doing 60km/h and under its still there while clutch is pushed in and tranny in neutral..i had the tires balanced and rotated and still no help...i notice the rear seal in the transfer case is going could that be causing a vibration, or rotors? it has new tie rods and 2 new ball joints. any tips or suggestions...i had one mechanic that didnt kno what it was and thinks its the tires, they are only half worn out by the way they are copper stt discoverer tires.

 

is it a high frequency vibration or low? If it is low it is probably the tires. thry getting them rebalanced and rotated.

 

A vehicle may exhibit a drive line shudder or vibrations while accelerating from a stop. The condition is most noticeable under heavy throttle acceleration and is usually only present at low speeds (below 25 m.p.h.).

 

what do you mean by low and high frequency if you mean like fast or slow its kinda fast...and for the tires i have had them balanced and rotated even put different tires and rims on for a bit to see if that would fix it and still nothing

 

Its the cooper stt's i have had several sets on my truck and they are VERY out of round they can balance them to a point that the machine is "satisfied" but not perfect. Try jacking the truck up one tire at a time like a half inch off the ground and spin the tires around, i'm sure you will see that the gap between the tire and the ground varies a fair bit around the rotation.

 

It could be the tires. It seems that you have checked almost everything else.

I've had pretty good luck with my Cooper STT's. They were round and took very little weight to balance; a lot less than the set of Terra Grapplers I had before. Mine are 35/12.50/18's.

 

Matt...One thing you may do is go to a large truck tire place and get the front tires skimmed. Then you know they are round and it will either eliminate the vibration or eliminate the tires as the cause. Not that expensive to do and you will love the smooth ride.

 

I just replaced my carrier bearing and all 3 u-joints and much of the vibration is gone, especially during stopping and slowing down,. As far as the other vibrations (around 60 mph) when I rotate and rebalance every 5k it goes a way for a few 1k miles. New shocks will go on tomorrow and get tires rotated and rebalanced today. Going to ride like a caddy monday.

 

i found a little dent in the drive shaft..this would prob cause the problem would it not? can they just be rebalanced?

 

I would think so.

 

Im going with the tire's, my buddy is always re balancing them and usually the vibe goes away...just my .02...

 

My truck had a shake from 95kms/hr-120kms/hr* the day I drove it off the lot brand new last year. Could not find what was causing it. Learned to live with it. Swapped out my Cooper STT's at 80,000kms for some Dick Cepeck FC-II and it drives like a dream now. I would have to bet on it being the tires as well. Good luck.

 

well i tried the tires rebalance and rotate even tried another set that i know were fine when i took them off and its still there.

 

With the vehicle still and running, put the trans in neutral. Push the clutch in or 3/4 of the way in and slowly sweep the engine RPM's up. Is this the vibration?

If so, it's simply engine harmonics that are being transmitted through the clutch line to the clutch pedal. No real way to get rid of it. There have been changes to the inline damper to help, but it's gotten worse as power ratings have continued to go up and up. Last I knew, there was a new damper that would be located at the slave that cut it in half, but I don't think it was inplimented. Your system should have the damper under the master cylinder.

 

Unbolt the driveshaft from the rear axle and rotate it 1/2 a turn then reinstall. I had a slight vibration on my 04.5 after the clutch swap. Rotated the driveshaft and all was good again. It seems like these trucks are very sensative to Ujoint wear. MY 95 joints where way worse and had no vibration were the 04.5 would shutter slightly from Ujoint wear that you would never suspect.