Community Forums

timz61 · 07-12-2006, 06:23 AM

During the course of our return from SoCal earlier this year, I noticed some vibration climbing the long grade on I-5 from Redding to Mt. Shasta. I stopped several times and checked tires and could find nothing wrong. The vibration continued to worsen and we managed to limp into a campground at Yreka. I called Spartan roadside service in the morning and they dispatched a tow truck that arrived within two hours. During the course of getting the rig ready to tow, the tow truck operator removed the driveline and told me he had found the source of the vibration - the universal joint was completely destroyed. There was a truck repair outfit about two miles down the road where he towed us and they were able to repair the driveline, reinstalled it and we were on our way. The U-joint had failed at less than 8,000 miles and there was plenty of lube on the shaft and in the joint itself. The repair shop told us that the ride height was probably out of spec and when we returned home the local Spartan service facility informed us that was indeed the case. When questioned, Spartan informed me that the ride height is set to factory spec when the chassis leaves the factory and is readjusted when the body is placed on the chassis. Newmar arrirmed what Spartan told me. In our case, the ride height was about 1" high in the rear resulting in the driveline failure. My question to others on this forum is how often and when is a ride height inspection admustment necessary?

timz61 · 07-12-2006, 06:23 AM

During the course of our return from SoCal earlier this year, I noticed some vibration climbing the long grade on I-5 from Redding to Mt. Shasta. I stopped several times and checked tires and could find nothing wrong. The vibration continued to worsen and we managed to limp into a campground at Yreka. I called Spartan roadside service in the morning and they dispatched a tow truck that arrived within two hours. During the course of getting the rig ready to tow, the tow truck operator removed the driveline and told me he had found the source of the vibration - the universal joint was completely destroyed. There was a truck repair outfit about two miles down the road where he towed us and they were able to repair the driveline, reinstalled it and we were on our way. The U-joint had failed at less than 8,000 miles and there was plenty of lube on the shaft and in the joint itself. The repair shop told us that the ride height was probably out of spec and when we returned home the local Spartan service facility informed us that was indeed the case. When questioned, Spartan informed me that the ride height is set to factory spec when the chassis leaves the factory and is readjusted when the body is placed on the chassis. Newmar arrirmed what Spartan told me. In our case, the ride height was about 1" high in the rear resulting in the driveline failure. My question to others on this forum is how often and when is a ride height inspection admustment necessary?

tmitchell · 07-12-2006, 02:06 PM

I have 27,000 miles on my 2004 DSDP 3807 Spartan.I went to the dealer Monday to see about changing the 275/70R22.5 tires, on the front, to 275/80R22.5. because I thought I was getting too rough a ride on some of the bad road surfaces up in the NE states. Instead they checked my ride heights and reset them to proper specs. They said my front was 5/16" too low and my rear was 1/4" too high. I will not be able to tell if the adjustment improved my ride until I leave Florida again, since the motorhome always rides great on the Florida road surfaces.
My one concern is that by changing the ride heights it might affect my steering,tracking,handling,etc. I was very happy with the way it was before, except for the harsh ride on rough roads.
I have read about several drive shaft related failures on the Spartan chassis either attributed to ride height or lack of proper greasing.
I assume my ride height wasn't off far enough to affect the angle of the driveshaft.

rebelsbeach · 07-12-2006, 02:10 PM

Left this in Newmar but wanted to note we now have a Spartan Chassis Forum on iRV2...I've linked these posts in the Spartan Chassis forum as well for better exposure.

Ken Roberts · 07-26-2006, 03:17 PM

We were in Harrisburg ,PA Cummins/Coach Care just a week ago and while there for other items mentioned that in last 1,000 miles our rtide quality left a lot to be desired. They agreed to checkit and found a leaking air valve in the rear bags, Spartan recall "Y" harness in trhe dash guages and you guessed it--the ride mheight was not to Spartan specs. All was corrected and we drove the rest of the way home to Crossville, TN totally amazed at the imm4ense improvement in the ride quality. Co-pilot and I are not in total agreement; but, I feel that the ride now is better than it was 2 years ago on day 1. In any event we are happy with both Spartan and the Coach Care folks in Harrisburg, Ken,'04 DSDP....

tmitchell · 07-27-2006, 03:56 AM

Ken,
Did they tell you what your ride height measurements were before they brought them back to spec.?
I was curious as to how far out of adjustment the ride height would have to be before it effected the ride quality.
I know the main concern for proper ride height is drive line angle, but my concern is with ride improvement.

Ken Roberts · 07-28-2006, 02:49 PM

No Tom they did not say and I totally forgot to ask. One of my concerns now is if the ride height will need to be adjusted periodically or was this a one time thing. I guess only time will tell.

My second concern is if Spartan has a given spec. why would Newmar or any other manufacturer change it? Maybe the coach manufacturer knows how best to build a coach; but, I would also think that Spartan is more expert relative to chassis issues including the proper ride height adjustment. Ken,'04 DSDP....

tmitchell · 07-28-2006, 05:01 PM

Ken,
Thursday I will take off on a 400 mile trip. I will stay in Florida,where the roads are real smooth, so unfortunately I doubt if I will be able to tell any difference in ride quality because of my recent ride height adjustment.
I figured I would take this trip before I decide to spring for new 275/80s to replace my 2 year old 275/70s. Everything I hear says that is what's needed to improve my ride on rough roads.
Tom

GaryKD · 07-28-2006, 06:34 PM

Tom,
What is the load range of your 275/70 tires? If they are not load range J, have you considered gettng 275/70 load range J? I have Michelin 275X70X22.5 load range J. There is plenty of carrying capacity, lower tire pressure and a very smooth ride. Just a thought.

tmitchell · 07-29-2006, 07:08 AM

I have the J rated 275/70s. They are adequate for my front axle weight. I put 110 psi in the front and 90 in the rears per the Michelin weight chart. I have no complaints about the handling,track-ability or steering with these tires.

When I drive on rough surface roads, mostly in the NE states, the MH ride is very harsh. I would say 85 percent or more of the roads I have driven, over the last 27,000 miles, the MH ride is very good. When I hit a rough road it feels like I have zero suspension give and cement filled tires.

From what I have read the 275/70R22.5 LRJs are noted for being very hard riding due to the shorter side wall which allows less give when you hit bumps and the fact that you have to go with the J rating
( which adds more stiffness to the tire) and run more air pressure to make up for the smaller tire.
When I switch to 275/80R22.5 LRH tires I am expecting a better ride over rough surfaces due to the H rating versus the J and a taller sidewall to absorb a larger percentage of the bumps. I will also be able to lower the air pressure to 100 psi.

IMHO the reason Newmar has gone to the 315/70s is because of all the complaints they have gotten about their rough riding motorhomes.
Tom