Maiden Voyage discoveries - tire vibration & Smart Bed surprise

[Cinequip]

No, that was "Dan Hicks and His Hot Licks".

[Cinequip]

Here is what Mark Harrah says the air bag heights should be:

"Front ride height is 10 and 5/16 and rear is 7 and 1/2, measured in the front from bottom of the frame rail to the bottom of the air bag, the rear is measured from the bottom of the frame to the weld on the axle tube."

I'm headed to Harbor Freight to pick up some heavy duty jack stands (in case the air comes down while I'm under there).

I would curious if Dale can confirm these heights when he is at Cummins.

Les Schwab spun balanced the front tires today, and threw auto-balance stuff in the rears. They also greased the U-joints. There was NO improvement in vibration on the short low speed drive home. I am driving freeway across town in the morning to get the A/C worked on, so maybe the rears will balance better by then.

[dgerstel]

I an not sure how this will work, but here goes. I thought that the info on the suspension on my 2002 showed how to measure the ride height, easier than what I have now. This is just a quick scan of this info I hope it is readable.

[Wally & Debbie]

Dale you are correct the manual is a little different for the 2002. these are the links to holland neway site hope they work. this one is for the rear http://www.thehollandgroupinc.com/NR...df_noorder.pdf and for the front http://www.thehollandgroupinc.com/NR...501RevBweb.pdf if this dont work you can do a search for holland neway and check thier pdf library. now that i have jumped the gun I see that these links are the new version, different from my old manuals. but you still end up with the correct ride hight. I'm not convinced this is the cause for the vibration and will be following to see what you find.

[Mike & Mike]

My vote is for Front End Alignment.

We picked up our used coach on the east coast and developed quite the vibration about halfway home to California. The vibration was only felt in a small range of speeds, like Cinequip mentions. Under that MPH, or over it, the vibration went away. One front tire got so worn by our continued driving that it was a candidate for replacement. BUT, we swapped it to the rear and brought an outside rear tire up to the front (the outside tires have the aluminum wheels), had a front end alignment performed, and life is good!

Good luck with yours!

[Cinequip]

So, as I mentioned above, Schwab spun balanced the front, and threw auto-balance stuff in the rears. After driving about 40 miles on freeways and city streets, the vibration is not better, perhaps even worse. It seems like it is originating in the rear. There is hardly any vibration on the wheel and floorboards, but lots of rattling from stuff in cabinets toward the rear.

Here is the theory:

The coach was parked A LOT in it's first year of life. I am guessing that the balancing "stuff" from original tire mounting, settled and solidified in one location in the rear tires - ie: causing the problem now. Throwing MORE stuff in the rears has just acerbated the problem. So, I plan to go back to Schwab and have them pull the tires and clean out all the stuff.

Anybody had experience with this type of tire balancing? Is it necessary to balance the rears at all??

[Flagelpater]

Hi, I am No Tire Expert, but, FWIW, I have heard of tires developing flat spots to the point of having them re-rounded. Other RVers have talked about it at seminars I have been to. I don't know about where the service is available, but maybe you could check the roundness yourself.

[EngineerMike]

S&M- I don't know how big a static balancer they have; if you can check the OEM balance of the tires they may not be far off.

As to 1st year setting around, that's the norm for a roller home so I don't buy that explanation. Yours moved how many miles in its time before you? Mine just sat 6 months without moving an inch and had zero tire balance/flat spot problems rolling to & from a rally. Flat spots are more a passenger tire story where the flexibility of the tire is larger by proportion, and then the car sets for very long periods. For H-rated truck tires I think you'd have to set for a year without moving at all to flatten the tire; especially since OEM pressure was 120 all around.

[Cinequip]

I bought a niffy floor creeper at Harbor Freight, and spent some time under the coach today. Pretty tight quarters, but I was able to measure ride height on all four, and fill the U-joint with red grease.

Rears are both at 7.25". Book says 7" and Mark Harrah says 7.5", so I'll call this good. Manual also says "within 1/4" for final measurement.

Fronts are at 10.25". Book says 10.25-10.5" and MH says 10-5/16". Again, seems to be within range and matching left to right.

I noticed that there are TWO U-joints. One at the output of the tranny and one at the input to the differential. The tranny end has a zirk fitting, which I filled, but the other one didn't seem to have any fitting.

I also took a good look at the steering gearbox and bracket. Mine seems to be very nicely welded with no evidence of stress. There is some movement on pavement steering, but nothing like I've seen in the scary videos.

I'll do another drive to see if my greasing helped anything on the vibes.

[Ted III]

Scott, if I were you I would be concerned that one of the U joints does not have a zerk fitting. I know that when I got my coach there was one missing in one of the joints which I added. I really would be surprised if the fitting is not missing. If there is no place to put one I would at some point in time take the joint apart and make certain it has plenty of lube. Otherwise how will you ever know?

[tinytom]

Just spoke to Bernie the Ex WRV Peak Chassis Manager. Explained your vibration problem and he told me they had the same problem from time to time. His suggestion was to swap the left and right front tires, according to him this almost always fixed the problem. If you have smart tire you will have to reprogram. PM me if you have any questions

[Cinequip]

Ted,

Your are correct. Upon closer inspection I found a total of 5 zirks! One on the body, and 2 each inside both U-joints. I had to move the coach twice to be able to reach all the fittings. I'm glad I did this myself - I can't imagine a shop taking the time to grease all of them.

[Cinequip]

Tom,

Thanks for the reply! The vibe is coming from the rear. I wonder if it makes sense to switch the rears left to right? I'm taking it to Scwab in the morning to have them REMOVE and check the balance/out of round condition of the rear tires.

[Cinequip]

Upon removal and spinning of the rear tires, Schwab found "flat spots" on one set of duals. They reinstalled that set so the flat spots are 180 degrees opposed. MUCH improvement. I can still feel the vibration between 40-50MPH, but it's a lot less. Dishes were rattling in the cabinets before, not at all, now. We will be driving 4-5k miles this summer, so I hope that the flat spots will ultimately work themselves out.

With this fix, now all of our maiden voyage issues are resolved! It's time to hit the road!

Thanks to everyone who offered ideas and suggestions to this post.