Engine/Transmission (1998.5 - 2002) Bad Vibration

[LSchick]

: Vibration Problem. 99 3500 auto 4x2. Loaded (no engine mod. s) approx 55000miles, vibration starts at 38 to 42 mph then around 50 to 55 mph. no other range and is very noticeable. The truck was fine until a new pinion seal and yoke were replaced all at the same time. Work was by an excellent dealer and staff who i know. Heres what has been done to correct the problem to date. The tires were balanced 4 times (Mich. tires)last time by a road force balancer. 6 brand new tires again installed, balanced 3 times,U joints inspected, another new yoke installed ,drive line checked for being in sink. This has been on going for 12 months, as i am over 200 miles from the dealer i cant spend the time i like to there, Have tried the old way of balancing the drive train by installing hose clamps on the drive shaft and rotating them, 3 clamps later each roted 8 times didn't make any changes in the vibration at all. This was on brand new pavement. HELP has anyone else run into this problem, or any ideas?

 

[Southwind]

You might look into installing a set of Centramatic continuous wheel balancers. They install behind the front wheels and between the rear duals. They will dampen most wheel vibration and extend tire wear by 20-40%. The company is located in Texas and I have used them on a previous truck and they work great. I have not installed them on my 99 because I don't have vibration problem. They can be found on the WEB or call them at 800-523-8473 or 817-332-3636.

Another company that sells a similar balancer is Sun-Tech at 818-882-8431.

 

[Dane]

"The truck was fine until a new pinion seal and yoke were replaced all at the same time".



99% of the time when a problem shows up right after doing work it's something done during the work. Forget about the tires and rims, they would not suddenly start causing problems out of the blue. You can verify this by having someone drive next to you on the freeway at the speed the vibration is felt. If the tire(s)/rim(s) is the problem they will see it wobbling compared to the others. This has to be done on a smooth road of course.



Focus on what they removed and replaced. You didn't mention center support bearing? Maybe they "tweaked" it getting the driveshaft out? Can you see what's vibrating with the truck on a rack running in gear?

 

[Whitmore]

My guess would be the carrier bearing just like Dane says



cheers, Kevin

 

[Motorhead]

I would look into having the driveline removed and spun balanced by a driveline shop.

 

[LSchick]

Have been unavailable since requesting imf, on the vibration problem, my thanks to all who answered . Will spend some more time on it as soon as time permits. Again my thanks.

 

[Vaughn MacKenzie]

I. shick,



Is the vibration a bouncy, shaking type of motion? Like in an unbalanced tire? I had this on my '98. Turned out one of the wheels was off center, IE, it had excessive runout. Have your wheels checked to make sure the center of the wheel is really truly center (load balancing should reveal this though). Another thing, make sure none of your wheels have a wobble (side to side motion, even in the slightest).



Is the vibration more of a low hum, such as the frequency of an out-of-balance driveline? Could need balancing or the carrier bearing is shot, like suggested.



Another thing, take a good look at your suspension and make sure there are no defects, like loose shackle bolts, U-bolt nuts, etc.



Take a look at your U-joints, maybe one is on the way out?



Check driveline phasing, which is checking the angles of the driveshaft relative to the transmission output shaft and the diff input shaft, as well as at the carrier bearing joint. These angles should cancel out.



Another quick check: Free rev your engine to the right speed and make sure it's not contributing to the problem by being uneven due to incorrect valve lash or injector/pump problem.



Good luck,

Vaughn

 

[LSchick]

thanks for the reply Vaughn, vibration is like a tire problem. I had a pinion seal and yoke replaced then went approx. 100 ft and had 6 new tires installed,Mich. same size that came of the truck. Left there noticed a bad vibration and returned in the a. m and had all 6 tires rebalanced on a road force balancer. saw the balancing done all at O. Had to leave to pick up my wife 600 miles away. Truck was the same, had 4 more balances done nothing changed. Replaced all 6 tires again road force balanced still no change. Had the rear yoke replaced again, still the same problem. The U joints were checked??????? and was told they were fine. Tried the clamps on the shaft as mentioned in the first post which didnt change anything. The wheels are abousletly perfect with no runout etc. Nothing loose underneath,have run in all gears(auto. )and problem still there ,have reved the engine to diff. R. P. M. s and there is no engine vibration. Even had the driveline checked for being in sink. There is no bearing noise that i can hear in the carrier bearing. Have a manual that suggests it could be the angle of the drive line is off or U joints. When time permits will remove all rear wheels, block the axle and run the truck, even remove the drive shaft and see whwt happens. Its bad enough my wife doesent even want to ride in it any more. This should have been found under warranty but wasnt ,same old story i guess. Will let you know what developes. Sorry for the long post.