Vibration when de-accelerating

[Danodaman]

Hey,
I went on a 400 mile road trip this weekend and my coach started vibrating at the rear axle when I let off the pedal at highway speeds. Last week I replaced my front tires and discovered some damage on one of my back tires so had my old front put on the rear. Could this be the problem? No vibration at speeds up to 50 mph ....but I like to go faster than my age...9 years ago. Dano

[OneRVer]

Have you checked the U joints on the driveline?

[justimagination]

Quote:

Originally Posted by OneRVer Have you checked the U joints on the driveline?

........Times two, tired will vibrate whether accelerating or coasting if their out of balance. As OP stated...........drive line or u-joints. Might look @ the center bearing support if so equipped. Good luck & travel safe.
David G.

[Danodaman]

The coach is new to me and I didn't consider that a pusher may have u-joints. I'll crawl under and check it out though.

[wa8yxm]

When it happened to me it was U-Joints.. So I'll join the U-joint team.

That was a Dodge Maxi Van, the book showed 2 U-Joints for that ride, Clerk at parts store said which one.. one was 10 bucks one 30, I handed him 30.. it fit. (The other one would not have, prices are rounded)

[OneRVer]

Quote:

Originally Posted by Danodaman The coach is new to me and I didn't consider that a pusher may have u-joints. I'll crawl under and check it out though.

Yep, you have a transmission and a rear end so you have to have a drive line. The difference is the drive line comes out of the back of the rear end instead of the front.

Please let us know what you find.

[Danodaman]

U joints don't clank when put in drive or reverse I greased them well and still get the vibe. Maybe it's time for the cummins shop.

[GOLDWINGER2]

They don't always clank when you change gears. Drop the shafts and do a visual check.
J

[Danodaman]

Quote:

Originally Posted by GOLDWINGER2 They don't always clank when you change gears. Drop the shafts and do a visual check. J

Check for out of round? Or any thing abnormal? Would they sell new joints at a Napa?

[GOLDWINGER2]

Quote:

Originally Posted by Danodaman Check for out of round? Or any thing abnormal? Would they sell new joints at a Napa?

The bearing needles can run dry and leave imprints on the mating surfaces. When you pull apart the joints you will see the damage. NAPA may have them, not sure, but they should be able to point you in the right direction.
J

[Twinsberry]

I'm sure its the u-joints. It just happened to me this weekend. Drove 1000 miles no problem. Started on my last leg and whamo, vibration in the rear. I knew one of the u-joints just went out. I just learned that I will put a grease gun in the RV and lube frequently. Before Cummins, I would take the driveshaft out and replace both u-joints. This will still be cheaper than Cummins telling you they couldn't find anything.
Chuck

[Danodaman]

Was your vibration at certain speeds or was it consistent?

[Danodaman]

Quote:

Originally Posted by Danodaman Was your vibration at certain speeds or was it consistent?

I got her fixed! Turns out my balance on the rear axle was way off due to the linkage not being attached. It threw the angle of the driveshaft off. Rides like a new coach now. Thanks everyone.