vibration at speed !

[OneLapper]

I had the same vibration on my 4106.  After doing all the normal stuff it turned out to be worn spline shaft on the drive shaft.  At higher speeds the sloppy shaft swung like two people using a jump rope.  It didn't move much, 1/4" at most, but it was enough to cause the entire coach to vibrate.

I put a new driveshaft in and it's been smooth as 25,000 pounds of silk going down the road ever since.

Mark

[TomC]

Drive at 65mph (LOL). Pull the drive shaft and inspect off the bus along with the Ujoints. Ujoints are not very expensive. Good Luck, TomC

[Lee Bradley]

I find it odd that the bus has to warm up before the vibration starts.  Could be a rubber mount that is not controlling a rotating load that as it gets warmer or a shaft that is losing alignment
as it warms; pinion shaft? But it does sound like a road speed vibration vs engine speed vibration; engine speed vibration would show up at a given rpm in each gear or out of gear. I'm with TomC the u-joints should be checked disconnected; most failures are from seized bearings that will not be detected by wiggling the shaft.

[sledhead]

Ya at 65 mph and 1650 rpm smooooooth ride but every now and then you need to clean out the carbon .                   dave

[TomC]

Every time you go up a hill you're cleaning out the carbon. Good luck, TomC