Truck shimmy

[Wick]

Jason,
I have a 1999 Century Class Frieghtliner that Show Hauler converted last June. It has a 32ft box on it and since day one I have had a shimmy or vibration in it that starts around 65 mph and gets worse the faster I go. I took it to a well know truck alignment shop in July (I took the drive tires off and replaced them with new ones first, it had recaps on it). They replaced 1 u-joint and aligned the front end. ($900.00+) That made no difference. I have tried changing the air ride height in both directions and driven it after each change but it seems to make no difference. I put it in my shop (I have owned a trucking co for the last 25 years) and pulled the back rear because I could hear a loud roar coming from it. We went thru that and found some wear but nothing really wrong. We rebuilt it anyway. The noise went away but no change in the vibration. I recently took it to a freightliner dealer and asked that they check it for rear axle angles and air ride height. They told me that they could find only the right front steer tire out of round. I do not believe that could cause what I am feeling, as I don't feel anything in the steering wheel. Do you have any other suggestions? I don't know if you guys streched the frame or not. Lonnie would know. What should the ride height be set at? Or the rear end angles be? Any help would be appreciated. I will have most July off so I can get some work done.
Wick Copland

[KAYERIVERCITY]

....how close are you to Cincinnati....try John's Spring Service up on Duff Drive 513-860-1200 ask for Tony or Rich....they will find it if you are near here....all they do is trucks-springs-alignments and problems associated with those issues.....you got any ConterAct in your tires?....forget the Centermatics-I sent mine back after a year of fooling around with them-long drive shafts present their own set of problems...get that egg shaped tire off there and get a good set of round tires on the front or at least have it ground round at a truck tire shop......geof

[Bigfoot Leveler Staff]

Man I need to get on the stick, I forgot to check this sight latley. sorry about that.
Well I am not certain if we did the stretch on your motorhome or not but the vibration you are talking about sounds alot like a driveshaft being out of balence, sometimes what happens is the little weights they put on or washers as they look like get spun off and once it hits a certain rpm it can start to vibrate, so that is what i would do, is take it to a place that does drive shafts and have them check the balance on them. let me know what you do find out.

Thanks Jason