On going vibration issue

[Vickie 4369]

Originally Posted by A1A JOE

What I thought was both a air ride suspension issue, (now fixed), then a bad ujoint issue, (now fixed), still leaves me with a vibration which occurs at highway speeds when I accelerate or decelerate or even just slightly change pressure on gas pedal.
I'm kindly asking anyone with a Newmar DP, with the Cummings 5.9 260HP tied to a Allison transmission that has had similar problems, resolved or not, to call me. 6142707633. Two repair shops later and no resolution is making me regret purchasing this 2000 Kountry Star.

Right height affects driveline angles that can lead to vibration, it cost me over $3000.00 to figure this out, first rebuilding then completely replacing my driveshafts chasing this.

Hindsight is always 20/20 the vibration was worse when I had my trailer on which lowered the ride height.

In my case Front engine Diesel I had to Rotate the rear end under the leaf spring by removing the block and machining 3 degrees angle in to it to roll the pinion down to correct the driveline angles, 30,000 miles later all is well.

So ride height and suspension bushing wear can both change driveline working angles that can put the driveshaft in to a whip like a jump rope.

Ted.

[A1A JOE]

I just had a reputable person advise me the trouble is in Pinion gear/gears and rear axle issues. Makes sense since avg. Warranty covered to 36,000 miles and coach now registers 41,000 plus miles. Sounds like a common issue with product obsolescence.

[Filthy-Beast]

Originally Posted by A1A JOE

I just had a reputable person advise me the trouble is in Pinion gear/gears and rear axle issues. Makes sense since avg. Warranty covered to 36,000 miles and coach now registers 41,000 plus miles. Sounds like a common issue with product obsolescence.

product obsolescence? On a 20 year old coach?

[Bigd9]

I feel uncomfortable with that diagnosis with only 41,000 miles.

Just wondering, did you have this vibration before you fixed the air ride suspension and the bad u-joint?

Has the differential oil been changed recently? Wondering if the coach has been in a flooded area where water could have gotten into the differential.

[A1A JOE]

41,000 .miles on a 36,000 mile warranty. To me, that is product obsolescence. Time is an illusion

[A1A JOE]

Very good information. Thank you

[A1A JOE]

Before air ride and ujoint was repaired, I had a total violent shudder throughout coach. After repair to ride height and drive shaft, only got a momentary shudder when changing load on and off rear end at highway speeds. I'm convinced there is slop in pinion gear to drive shaft. Advised accordingly. That is my next move. Rear axle examination. Thanks for your reply.

[mackwrench]

Joe, it's your loot, but I'd be hard pressed to believe you'd have a rear carrier failure that lead to driveline vibration with out a few other signs.

A sloppy, worn or failed pinion gear/bearing is noisy, you'd for sure hear it even from the driver seat, and the input seal (behind the yoke) would probably be pouring oil as the vibration beat the seal out as well.

The rear axle/carrier assembly in your coach is a stout piece that I've seen run a million miles in a truck

..... you sure the ride height is right? It ain't gonna cost much to find out.

What brand of chassis is your coach and rear axle weight rating? I'm thinking people here can come up with the procedure to check it ... it'd only have to be out of spec a little to cause the vibration you described....

[Bigd9]

"total violent shudder throughout coach" sounds like a U-Joint all right. Now I'm wondering if your driveshaft has a carrier bearing somewhere maybe in the center of the shaft? As has been asked before, what chassis does your coach have?

[A1A JOE]

I have a Spartan chassis. In addition to the vibration, I'm now getting a rotational "growl" and howel that grows louder at a higher speed and lower at a lower speed. I'm taking to a third shop next week. Sooner or later I'll get to the bottom of this.

[A1A JOE]

The violent shudder stopped upon replacement of ujoints. No more like driving on the roads side rumble strip.

[guardrail53]

Originally Posted by Bigd9

I feel uncomfortable with that diagnosis with only 41,000 miles.

Just wondering, did you have this vibration before you fixed the air ride suspension and the bad u-joint?

Has the differential oil been changed recently? Wondering if the coach has been in a flooded area where water could have gotten into the differential.

I agree with Bigd9 on this! Sounds like it has been in a flood! These rear ends are very heavy duty, and rarely fail in a MH use! If it was used to pull a very heavy trailer, maybe, but still? Where did this MH come from, was it from south Texas area? Has the differential oil been changed lately, if not, drain it and inspect it, pour it through a cheese cloth, see what kind of stuff gets caught in the cheese cloth! With only 41,000 miles, not likely it would fail, unless it had water infiltration! I hope it is not the rear end, as it will be costly to fix! Good luck! I would call Spartan and see where they suggest you take this, so you have someone that knows MH's check this out!
Rail!

[A1A JOE]

Thanks for your reply. I am digesting every response. This diesel pusher is pushing my buttons for sure.. regardless, I will take your advice on draining differential oil. I have only owned it two months. Have no idea of its prior residence, maintenance, or repair history. It cosmetically is in almost new condition - wish that was indicative of great maintenance schedule. Prolly wouldn't be having these issues if it was...

[John Jones]

It sounds like you've checked your ride height. That would have been my guess. My coach was riding a little low in the rear, when I would peddle the throttle I would get a rumble strip sound in the coach. I took out my driveline, had the U joints checked, reinstalled the driveline, adjusted the ride height and the problem went away.