Sunseeker 2650 CDWS Vibration

[tingefamily]

Our motorhome, on an 2015 E450 Ford chassis with 110,000 kms, has a noticeable vibration, starting at about 65 kms per hour, mostly disappearing at about 90kmph. The tires are new and balanced. My suspicion is something with the driveshafts (3) or steady bearings (2) or the u-joints (3). Has anyone else had this problem and how was it fixed? I am thinking of dropping the driveshafts and checking all the u-joints, but I think it has something to do with balancing the whole drive train, so I am reluctant to wrestle with all that iron just to have it all dropped anyway for balancing. After 2 years, I have got to get this fixed and I have a driveline shop picked out, but thought I would check with this forum first. Am I missing another source for the vibration?

[RamblerGuy]

Originally Posted by tingefamily

Our motorhome, on an 2015 E450 Ford chassis with 110,000 kms, has a noticeable vibration, starting at about 65 kms per hour, mostly disappearing at about 90kmph. The tires are new and balanced. My suspicion is something with the driveshafts (3) or steady bearings (2) or the u-joints (3). Has anyone else had this problem and how was it fixed? I am thinking of dropping the driveshafts and checking all the u-joints, but I think it has something to do with balancing the whole drive train, so I am reluctant to wrestle with all that iron just to have it all dropped anyway for balancing. After 2 years, I have got to get this fixed and I have a driveline shop picked out, but thought I would check with this forum first. Am I missing another source for the vibration?

I had a weight come off the driveshaft of our 2010 E450 chassis Sunseeker, which instantly caused a vibration. If you have yours rebalanced, be aware that if your wheelbase was extended, as most are, Forest River rebalances the entire assembly of the added driveshaft section plus the original sections. If you rebalance only the section that lost a weight (if you identify it), you'll throw the assembly out of balance. Be sure the shop can balance the entire three section assembly together, at least 3500 rpm (about 60 mph), with 4000 rpm preferred. The first shop I took mine to only did a section at a time, and then only to 1800 rpm. That didn't work.

Of course, this doesn't really answer your question, and yes, the problem could just be u-joints or steady bearings. Look very closely with good light and you might find where a weight is missing. Mine were painted after balancing, so the unpainted spot was the clue where the weight was missing. If you can find a good shop to rebalance it, it may be worthwhile to have it balanced and replace the u-joints and bearings all at once, considering the mileage your chassis has. The balance was about $125. I replaced the u-joints with new ones that had grease fittings, even though none seemed to be bad.

Here's a link to my full, and quite long, discussion.

https://www.forestriverforums.com/fo...oad-67039.html

[JohnandSandiOnTheRoad]

Originally Posted by RamblerGuy

I had a weight come off the driveshaft of our 2010 E450 chassis Sunseeker, which instantly caused a vibration. If you have yours rebalanced, be aware that if your wheelbase was extended, as most are, Forest River rebalances the entire assembly of the added driveshaft section plus the original sections. If you rebalance only the section that lost a weight (if you identify it), you'll throw the assembly out of balance. Be sure the shop can balance the entire three section assembly together, at least 3500 rpm (about 60 mph), with 4000 rpm preferred. The first shop I took mine to only did a section at a time, and then only to 1800 rpm. That didn't work.

Of course, this doesn't really answer your question, and yes, the problem could just be u-joints or steady bearings. Look very closely with good light and you might find where a weight is missing. Mine were painted after balancing, so the unpainted spot was the clue where the weight was missing. If you can find a good shop to rebalance it, it may be worthwhile to have it balanced and replace the u-joints and bearings all at once, considering the mileage your chassis has. The balance was about $125. I replaced the u-joints with new ones that had grease fittings, even though none seemed to be bad.

Here's a link to my full, and quite long, discussion.

https://www.forestriverforums.com/fo...oad-67039.html

We have a 2019 Sunseeker 2500TSF. It had a ‘harmonic vibration’ similar to the sound of driving on the ‘rumble strip’. It would start around 60 mph (96 km) and become substantially less at 66 mph (106 km) but still slightly present. We had the driveline re-balanced and while it helped with over-all vibration, it did not fix the problem. The actual fix was the addition of degree shims added to the rear axle, which corrects the pinion angle to the proper angle. Not particularly a cheap fix but it corrected the problem.

[RamblerGuy]

Originally Posted by JohnandSandiOnTheRoad

We have a 2019 Sunseeker 2500TSF. It had a ‘harmonic vibration’ similar to the sound of driving on the ‘rumble strip’. It would start around 60 mph (96 km) and become substantially less at 66 mph (106 km) but still slightly present. We had the driveline re-balanced and while it helped with over-all vibration, it did not fix the problem. The actual fix was the addition of degree shims added to the rear axle, which corrects the pinion angle to the proper angle. Not particularly a cheap fix but it corrected the problem.

Forest River I think other RV manufacturers had a lot of trouble with the E350 and E450's when Ford switched to their 6-speed transmission. I think they stopped delivery for weeks while FR and Ford figured out the fix. They eventually had to shim the rear axle to adjust the pinion angle. In my case, it ran smoothly before the weight came off, so the pinion angle adjustment should not have been part of the problem. I never got it balanced as smoothly as I would like. I checked the angles of all the driveshaft sections against the transmission and pinion angles, and they were all within the acceptable range.

[tingefamily]

Thanks for the help. I have an appointment to have the driveline rebalanced and will let them remove it and balance it. The cost was not excessive and living in a small town far removed from the big city, more convenient. I'll let you all know if it fixed the problem. The shop also does differentials, so hopefully they will know if its the diff or the driveshaft.

[nic7320]

All it takes is a single crushed needle bearing inside one u-joint to cause a vibration like that. I had one fail on a Dodge class B campervan, while going to see the solar eclipse. Up to 30MPH going up hills it was fine. Over that, it tried to shake itself apart. Going down hills, I could go faster. It was a long drive made even longer by limiting my speed up the hills, and everyone questioned if we would make it. Fortunately, u-joints are a cheap fix.

[briantompo]

RISE, old thread, RISE..!

Hello All,
I recently bought a 2019 Sunseeker 2500TS(F) with 20k miles. I love the floor plan and think it’s a great camping rig but the vibration & resonance at highway speed is eating my lunch. It starts buzzing around 62 and by 64 it makes conversation difficult. First time I heard it I pulled over to check driveshafts and heat shields but everything looked ok. At lower speed it’s quieter but the floor still vibrates.
I’ve altered tire pressure, ballast, balanced tires, rotated tires, replaced tires, added that missing idler pulley then changed the serpentine belt, shimmed, secured & attached dampers to every heat shield, removed the spare, re-hung the spare, changed air bag pressure and finally realized it was the air bags that made a difference in noise level. The noise diminished when I had 40psi or more in the bags. Hmmm….
I checked underneath for clearance issues at various air bag pressures/rear ride heights but found no evidence of anything rubbing or buzzing against the frame or floor. I noticed the 3 driveshafts don’t go in a straight line from the trans to the diff but are offset about an inch to the passenger side by the aft carrier bearing. I’m told the lateral offset is intentional. I’m still surprised by how high the operating angles are between the 3 shafts and also the pinion. It doesn’t look like it’s ever had a wrench on it & I see no seal leaks, u-joint failure nor any sign that a driveshaft weight came off. I’ve measured & recorded driveshaft & pinion angles but have not compared phase angles, yet. Driveshafts come off next week for closer scrutiny and diff fluid checked for metal.

In the meantime, does anyone have drivetrain specs from Forest River or other class C on E450 chassis? Specifically, I’m interested in driveshaft angles, runout, carrier bearing bracket heights, pinion angle, etc. Basically, any drawings, build sheets, bulletins or spec sheets I can use to check mine against. It may be as simple as a sneaky u-joint but if I gotta shim carrier bearings or rear end to change angles, I’d like to do it once & be done with it. I’ve already spent too much time underneath this thing.

I realize this an old thread but it seemed as good a repository as any for E450 driveshaft vibration. I’ll report back when I resolve this.

Thanks, Brian

[TitanMike]

Check any slip joint in the drivelines to make sure they aren't assembled one spline off.

Some have a "blind spline" that won't allow this and others don't which can allow for misalignment and the type of vibration you describe.

A quick check would be to move vehicle fore or aft until one u-joint cap is level side to side then check remaining caps with small level.

Any significant difference can be the culprit.

[briantompo]

Update to my own post above: I apologize for the length but maybe this saves the next guy from reading hundreds of pgs of forum posts that trail off into oblivion without resolution.
To recap, I’ve got a 2019 Forest River 2500TS class C on a Ford E450 that had a vibration & howling noise above 62mph. It also made noise when decelerating through 58mph & again from 54 down to 50 with foot off the gas. I bought it with 20k miles & while I don’t know the RV’s history before my ownership, the foam overspray on the driveshafts, slip yoke & bearing supports made it appear this drivetrain was original.

To stop the floor from vibrating and the howling noise above 62mph required changing the pinion angle, replacing one u-joint that looked & felt fine but had a .050” wobble, having the driveshaft straightened & re-balanced and changing the height of BOTH carrier bearing brackets to change the driveshaft angles. I started with working angles of 3°, 4°, 7° and 4° and finished with 1°, 1°, 1° and 3°.

The initial transmission & pinion angles differed by 2° with no air in the bags but could be brought to within 1° if I inflated the bags to 80psi. I couldn’t SEE the drivetrain changing angles when the bags were inflated but a digital inclinometer placed on the transmission, driveshafts and pinion flange revealed the pinion rotates UP 1° and the driveshafts DO change angles as the bags are inflated. I assume the pinion rotates down during deceleration & that would explain the noise while slowing under no load. For my coach, removing the 1° shims from the rear end matched the trans and pinion angles. I’ve heard other owners have had to ADD shims to correct theirs. I did not attempt to shim the aft transmission mount but there appears to be room to raise it instead of rotating the rear diff.

Matching the trans & pinion angle eliminated the howling noise and SOME of the vibration. Driveshaft repair & balance eliminated MOST of the high freq vibration. Changing the driveshaft angles by re-shimming the carrier bearings was a further refinement. I lowered the front carrier roughly 9/16” and raised the rear carrier roughly 3/4”. The howling noise is gone and vibration massively reduced according to seat-of-the-pants and NVH phone app
.
Moving the two, best (roundest) wheels to the front & having them road-force balanced got rid of the steering wheel & side mirror jiggle. At this point I’m fine tuning driveline angles but feel these changes have resolved the noise & vibration to an acceptable level for this chassis.
For reference, the phase angles over the 9’ length of my 3 driveshafts varied by 2.7° The slip yoke IS “keyed” so it only fits one way & cannot be assembled “one spline off”. There were no metal shavings stuck to the rear diff magnetic fill plug nor to a magnet shoved down in the diff.
Brian

[BehindBars]

Originally Posted by briantompo

Update to my own post above: I apologize for the length but maybe this saves the next guy from reading hundreds of pgs of forum posts that trail off into oblivion without resolution.
To recap, I’ve got a 2019 Forest River 2500TS class C on a Ford E450 that had a vibration & howling noise above 62mph. It also made noise when decelerating through 58mph & again from 54 down to 50 with foot off the gas. I bought it with 20k miles & while I don’t know the RV’s history before my ownership, the foam overspray on the driveshafts, slip yoke & bearing supports made it appear this drivetrain was original.

To stop the floor from vibrating and the howling noise above 62mph required changing the pinion angle, replacing one u-joint that looked & felt fine but had a .050” wobble, having the driveshaft straightened & re-balanced and changing the height of BOTH carrier bearing brackets to change the driveshaft angles. I started with working angles of 3°, 4°, 7° and 4° and finished with 1°, 1°, 1° and 3°.

The initial transmission & pinion angles differed by 2° with no air in the bags but could be brought to within 1° if I inflated the bags to 80psi. I couldn’t SEE the drivetrain changing angles when the bags were inflated but a digital inclinometer placed on the transmission, driveshafts and pinion flange revealed the pinion rotates UP 1° and the driveshafts DO change angles as the bags are inflated. I assume the pinion rotates down during deceleration & that would explain the noise while slowing under no load. For my coach, removing the 1° shims from the rear end matched the trans and pinion angles. I’ve heard other owners have had to ADD shims to correct theirs. I did not attempt to shim the aft transmission mount but there appears to be room to raise it instead of rotating the rear diff.

Matching the trans & pinion angle eliminated the howling noise and SOME of the vibration. Driveshaft repair & balance eliminated MOST of the high freq vibration. Changing the driveshaft angles by re-shimming the carrier bearings was a further refinement. I lowered the front carrier roughly 9/16” and raised the rear carrier roughly 3/4”. The howling noise is gone and vibration massively reduced according to seat-of-the-pants and NVH phone app
.
Moving the two, best (roundest) wheels to the front & having them road-force balanced got rid of the steering wheel & side mirror jiggle. At this point I’m fine tuning driveline angles but feel these changes have resolved the noise & vibration to an acceptable level for this chassis.
For reference, the phase angles over the 9’ length of my 3 driveshafts varied by 2.7° The slip yoke IS “keyed” so it only fits one way & cannot be assembled “one spline off”. There were no metal shavings stuck to the rear diff magnetic fill plug nor to a magnet shoved down in the diff.
Brian

Thank for the excellent, detailed write up. Too bad the unit wasn’t built right to begin with, but your story will help others with similar problems. My 2020 Sunseeker 2440DS had a vibration that began at 62 mph. After I had the Liquid Spring system installed in the rear, the vibration was gone. I suspect pinion angle was the issue, and I just got lucky that when the LS system was installed they just happened to get it right.

It’s a bummer to get a new, or new to you motorhome and then discover it has some annoying drive line traits