Coach vibration and shake

[Unplanned Tourist]

Originally Posted by Dsallach

I have a 40' 2000 Monaco Windsor. At speeds usually between 60 and 70 the coach has a shake/vibration that rattles the coach. The shake vibration is fairly rapid and seems to me to be almost an up-down hop type shake. The rear view mirrors shake, the gps mount loosens and the cabinets rattle. The vibration is similar to what used to occur with a bad u-joint in a 70s car. The vibration seems to be worse in the front but, I always drive so I don't know that for a fact. The vibration is noticed more though the coach rather than the steering wheel. The steering wheel does not vibrate left to right again it is more of an up down shake. This does not appear to be a shock issue. The steering linkage, kingpins etc have all been professionally checked as have the u joints. The tires are new and have been spun balanced and checked (twice) for 6 way trueness. Shocks are good. I am very mechanical and have worked on my own vehicles for 50 years. I bought the coach used and the problem has existed since I bought it, previous owner is deceased so I cannot track it back further. This one has me stumped. Any thoughts?

Is the vibration there but only maybe 1/2 as bad at around 30-35 mph? If so definitely check the driveline phase. It's harmonics, and would take a book to explain! If it just gets worse the faster you go, probably u-joint. Sounds like you have some test driving to do! Be safe.