Tranny Tailshaft Vibration?

[B25guy]

Here's a long shot...when I read that your mirrors shook...thirty years ago or so I had a 1/2 ton Chevy pickup that at around 45mph the mirrors shook (kinda like my Harley now, but it wasn't a v-twin HD motor doin' the shakin'). Higher or lower in speed and it was fine (sound familiar?). I had a GM shop manual and tore into the rear end, not a full-floater like your moho but similar enough perhaps. Long story short is that I found there was a crushable sleeve between the two pinion shaft bearings that provided a pre-load and kept the bearings snug up against the cups/races. Tightening the yoke bolt more than once or twice rendered this pre-load sleeve used up and required another. When I put a new sleeve in and tightened the yoke to spec, I never had the vibration again. BTW, this truck was a long bed and had a two-piece driveshaft and everybody thought tailshaft and/or hangar bearing....not this time.

good luck

[GlenCoombe]

I'm a little behind on my posts so let me catch up.
I took Airstream One into the shop last week to have the U-joints checked. We've been chasing this chassis vibe for quite a while now.
Found earlier after a transmission service that the vibe was about gone after that service but it returned by the time I got to Orlando. The crossmember supporting the tranny had been removed and reinstalled to do the service.
Well they found that the front joint was a bit worn but the remainer where o.k. But what was found was a broken tail shaft mount! I've not been on the road since but am expecting not to have the vibration I've been chasing.

[swebster]

Glen,
Intersting that you mention this. I was just pricing new engine and transmission mounts. I'm not sure I think that they are part of the problem....but since I have almost 200K miles on the coach and the mounts are cheap (less than $60 for everything) I thought about replacing all of them for good measure.

I do feel a fair amount of vibration in the steering column even at idle and given the other [lack of maintenance] items I've found on my coach since I bought it I would not be surprised if they've never been replaced.

Of source it looks like it will be a terrible job to do - right up there with the u-joint/carrier bearing replacements.

[GlenCoombe]

Steve...et.al. I'm happy to say the road test yesterday had no vibe time will tell if we got it though as we thought so and it came back after the tranny service. Mounts control so much with the big blocks I'm certain that with the mileage on your rig being as high as it is that new mounts will help to reduce if not remedy your vibrations. The only obstacle is installation. Good luck.