Community Forums

Marca · 04-08-2016, 11:42 AM

Between 40 to 50 mph, my motorhome is experiencing a mild vibration/sound in the drive line particularly under load. All other speeds seem to be OK. It kind of acts like minor lugging of the engine when one is learning to drive a stick shift car and shifts too soon.

Thinking the ride height might be causing it, I took it and the ride height specifications to Freightliner Truck here in Tampa, FL. I asked them to check the ride height and never did get to talk to the actual mechanic performing the work. I was only ALLOWED to talk to the service writer who ran back and forth between us relaying information. I hate this!

She said he just keeps saying it is not a Freightliner and he doesn't know what to do.

Well with the instructions I gave him from the technical library and posts on this site, I think I could have done it but wasn't particularly keen about crawling under the coach.

So he finally measured the ride height and said it was within the specs I gave him. Then he says he needs the drive line angle specifications due to some excessive yoke deflection on the drive shaft to rear angles. He did measure and record the angles but since he only knew Freightliner and I didn't have the specifications he didn't know if they were correct or not. So I called Keith at Redland's Truck and told him my predicament.

Keith strongly suggested (won't actually use his exact words on here) that I have them button it up and get to another shop because he was concerned they might really mess it up. He recommended Josam Alignment in Orlando and to have them call him if they have any questions. Does anyone know of any drive line specifications that I need to take with me for my appointment with them next Tuesday or have any other suggestions? Thanks in advance!

chrisancher · 04-08-2016, 04:23 PM

You won't need any specs at Josam in Orlando. They are the best in the business,

But you will need a big check book

They are worth every penny

Chris

wolfe10 · 04-08-2016, 05:43 PM

Have never seen drive line specs published for a motorhome.

But measuring ride height is quite easy, and that determines drive line angle!

Brett
2003 Alpine 38FDDS

JLMunsil · 04-11-2016, 12:48 AM

The pinion angle on my 08 is 2 1/2 degrees. Pinion angle should be greater than 0 and not more than 3 degrees by design. This should only be used as a reference. Jo SAMs will do what's necessary to correct your problem regardless of spec.
They corrected my coach from pulling to the right even though it was set to spec, by shimming to change the right side caster angle. Ride height should be verified first.

08 34-ft fdds

Rusty Bear · 04-12-2016, 11:33 PM

Have you checked the U Joints? I had to replace mine this January. Mine started as a minor vibration and got worst. Have you had this problem for a long time, and if not why would ride height change suddenly?

dhschultz39 · 04-13-2016, 08:17 PM

Quote:

Originally Posted by Chuck & Marca

Between 40 to 50 mph, my motorhome is experiencing a mild vibration/sound in the drive line particularly under load. All other speeds seem to be OK. It kind of acts like minor lugging of the engine when one is learning to drive a stick shift car and shifts too soon.

Thinking the ride height might be causing it, I took it and the ride height specifications to Freightliner Truck here in Tampa, FL. I asked them to check the ride height and never did get to talk to the actual mechanic performing the work. I was only ALLOWED to talk to the service writer who ran back and forth between us relaying information. I hate this!

She said he just keeps saying it is not a Freightliner and he doesn't know what to do.

Well with the instructions I gave him from the technical library and posts on this site, I think I could have done it but wasn't particularly keen about crawling under the coach.

So he finally measured the ride height and said it was within the specs I gave him. Then he says he needs the drive line angle specifications due to some excessive yoke deflection on the drive shaft to rear angles. He did measure and record the angles but since he only knew Freightliner and I didn't have the specifications he didn't know if they were correct or not. So I called Keith at Redland's Truck and told him my predicament.

Keith strongly suggested (won't actually use his exact words on here) that I have them button it up and get to another shop because he was concerned they might really mess it up. He recommended Josam Alignment in Orlando and to have them call him if they have any questions. Does anyone know of any drive line specifications that I need to take with me for my appointment with them next Tuesday or have any other suggestions? Thanks in advance!

Chuck & Marca: After checking to ensure the U-joints are okay (if this phenomena just started, U-joints possible suspect) and the drive-shaft slip joint is okay (requires dropping drive shaft and pulling back the shaft seal to inspect slip joint), and bolts tight on flange to parking brake, you also have to check the drive shaft to pinion shaft at greater than 1.5 degrees (to get the needle bearings in the U-joints to "roll" ever so slightly), but no more than 10 degrees according to Meritor specs. The drive shaft angle is controlled by "tipping" the differential carrier with the strut brace (looks like a big steering tie rod) connected between the diff carrier (top) and the frame. If all of that is good, to eliminate a low speed (3 - 5 mph) shudder, I had to align the knuckles of the drive shaft sections (see my several posts this forum re: "low speed drive train shudder"). 1st pic is DS as removed; 2nd pic shows seal at splined area; 3rd pic shows right-hand section of DS rotated 90 degrees to align the knuckles and the U-joints. Now runs perfectly smooth at all speeds.

jacwjames · 04-13-2016, 08:30 PM

Is this a recent problem?

Did you have any work done on your RV. Did you have it towed?

I had to have my coach towed to Cummins Crosspoint. When they finished the work I had several major issues, one of them being that they didn't put the driveshaft back in phase. I corrected myself, the driveshaft was marked so it wasn't rocket science.

Marca · 04-16-2016, 03:59 PM

UPDATE:
I took the Apex to Josam Truck Alignment in Orlando and here are the findings:

Last summer I had new tie rod ends installed, new Bilstein shocks, a rear adjustable torsion bar replaced, and the steering reinforcement kit installed in Mishawaka, IN. Also, the ride height was checked and it was aligned. I had to take it back the second time because it rode like a log wagon. They admitted they never test drove it and readjusted and realigned it. The problem started sometime after this work was done on the way to Florida late last year.

Then a couple of weeks ago I took it to Freightliner in Tampa and they checked the ride height and said it was within the specs I gave them from the Alpine Technical Library. They couldn't help any more because they said it was not a Freightliner chassis and I needed to get the drive train angles. They did not change anything.

Upon Redland's advice, this past week, I took it to Josam. The tie rod ends were not installed correctly as the bolts were hitting something and causing a clunking sound on hard turns to the right. They fixed that. They checked the U-Joints and said they were fine. They checked the ride height and it was not correct so adjusted it to the same specs from the Alpine Technical Library given to Freightliner earlier. They aligned it and took it for a test drive. Problem was still there. They next adjusted (shortened) the new adjustable torsion bar and test drove it. Seemed better so they had me drive it. It was much better, not perfect but almost. By adjusting the torsion bar, it changed an angle slightly in the drive train. I have to let them know if it needs further tweaking but so far so good.

Now here is the real kicker......Josam said that I don't have a Peak Chassis but rather I have a Freightliner.

Chuck always said this 2006 APEX didn't handle as well as our 2000 Alpine with the PEAK chassis and questioned WRV about it several times. After my latest experiences, I think he may have been right. I have all the years' brochures from WRV and they all say PEAK chassis. Can someone enlighten me regarding what makes it a PEAK chassis and not a Freightliner? Or did a few Freightliners sneak through the production line?

In addition, the Service Manager at Josam said the new Tiffin Powerglides coming through his shop are Freightliner chassis. I understood they were as close to a PEAK chassis as one could get.

Thanks to everyone who responded to this post. It sure drives a lot better than it did!

Old Scout · 04-16-2016, 06:43 PM

Hello Marca--sorry to read about your drive-shaft issues. Probably not related but didn't you and Chuck have some significant problems with your differential pinion bearing a few years back?
I think it is highly unlikely that a Freightliner frame got on the WRV production line--the Peak name plate should be on the side of the frame, under the driver's position. Could be that someone else is building the new Tiffin Powerglide chassis but it is definitely a Tiffin proprietary frame.
Wasn't sure what you call the forward facing link bar [as opposed to side to side track bar]. Given the design of our trailing arm suspension, I guess the bar would work in parallel with the suspension arms--like a trapezoid?????
Look forward to hearing about the final outcome on your drive-line.

Marca · 04-19-2016, 01:52 PM

Hi Old Scout,
Thanks for your response. Yep, we were the ones who had the differential failure on the way to the Calgary Stampede and I had wondered myself if there could be a connection. My understanding is that the pinion gear bearing hanger started disintegrating. We caught it early before a catastrophic failure occurred. A sound in the rear kept getting louder and louder. A new differential was installed and paid for by Good Sam CSP after I produced my maintenance bills showing we had the differential grease/oil changed a couple of times during our ownership. The last time was 700 miles before the failure. This sound/vibration was not like that sound. Trying to decide now if I want to return to have it tweaked a little more or leave well enough alone. It is so much better than it was. Sometimes with these animals it is better to leave well enough alone or close to well enough alone.

Old Scout · 04-19-2016, 04:28 PM

Marca--appreciate the feedback--the rear axle set-up is a bit different on my 03 [19k] vs 05 and new coaches with 20k axles. Most noteably, my 19k axle doesnt have the forward-facing "track" bar. Having said that, the axles on both models are square and bolted solidly to the trailing arms. Accordingly, I really cant see how "adjusting" the forward-facing bar on top of the differential, changes the pinion angle. Clearly, changing the ride height [air bags] would have an effect, but not the upper bar. Seems like you would have to put shims in the shackles between the axle and the trailing arms to tilt the axle foward or back???? Hopefully, someone will explain how they are "adjusting" the pinion angle via the upper bar.......dean

dhschultz39 · 04-19-2016, 07:29 PM

Quote:

Originally Posted by Old Scout

Marca--appreciate the feedback--the rear axle set-up is a bit different on my 03 [19k] vs 05 and new coaches with 20k axles. Most noteably, my 19k axle doesnt have the forward-facing "track" bar. Having said that, the axles on both models are square and bolted solidly to the trailing arms. Accordingly, I really cant see how "adjusting" the forward-facing bar on top of the differential, changes the pinion angle. Clearly, changing the ride height [air bags] would have an effect, but not the upper bar. Seems like you would have to put shims in the shackles between the axle and the trailing arms to tilt the axle foward or back???? Hopefully, someone will explain how they are "adjusting" the pinion angle via the upper bar.......dean

Evening Old Scout,
To help you see how tilting the differential carrier changes the drive shaft to pinion angle, find attached a .pdf file of 3 pages from the Holland Maint & Parts manual depicting the rear suspension on my '06 Alpine. On page 2, part #13 (looks like a very big tie rod) permits controlling the tip of the differential carrier by changing its length (note that the torque tube ties into the carrier at the top of the carrier [slightly to right and down from the #21], exerting a "twisting" force on the carrier. On page 3, note how the pinion shaft c/l is moved relative to a ground plane, and of course, relative to the input drive shaft. On my '06, the engine transmission assembly is down by the output end (DS end) by a couple degrees, so with my carrier tipped slightly down by the pinion, I end up with about 1.5 deg between the transmission and DS, and about 2.5 deg among the DS and the pinion. These numbers are good according to Spicer [my U-jpoints] to get the needles in the U-joints to roll ever so slightly to prevent a wear set occurring. Note that rotating the carrier in this manner changes the ride height adjustment significantly, so setting the proper diff angle preceeds setting the ride height. Incidentally, setting ride height changes the DS angles (lifts / lowers engine), but the effect on my coach wasn't so pronounced as setting the diff carrier angle. Hope this helps.
Happy travels.
resp/dhs

Old Scout · 04-19-2016, 10:18 PM

DHS--OK--I see the differences between the early and later Alpine axle configs. My 03 axle is u-bolted directly to the trailing arms so no pivot point to adjust pinion angle. Also explains why I dont have a second adjustment bar on top of the differential. Appreciate the education--I learn something new about Alpines everyday.....
PS--this begs a second question: I have heard owners indicate they had their rear axle "thrust angle" adjusted during a 4-wheel alignment [ie to cure "dog-tracking"]. Doesnt seem possible once pivot arm bolts are welded in place--ref page 3 of your attachment.

dhschultz39 · 04-20-2016, 10:42 PM

Once the frame bracket assembly (Item 1a, p.2) is bolted / welded to frame, and the equalizing beam (Item 3) is bolted up, seems like the fore / aft position of the carrier is set. Probably what is anecdotally being reported is the adjustment of the Track Bar (Item 12, the "anti-sway torque tube) to move the carrier left or right under the frame of the coach. If that adjustment were grossly out, "dog-tracking" could certainly be observed by Mother driving behind the coach, reporting to Pop, "What the devil is wrong with the coach?" - i.e., rear wheels not in line with front wheels.
WRV set my coach up with exactly the same left and right rear wheel clearance to the frame - I have no idea how that tracks relative to the front wheels..., but since the coach handles so well, leaving that sleeping dog lie quietly.
r/dhs