2006 Monterey Vibration

[Richard Davis]

I have developed a vibration on my '06 Monterey that is speed related.  It starts at about 50 mph, increases until about 55 and diminishes above 60.  At first I thought I had a tire balance issue, so I had the tires inspected and rebalanced.  That made no change, but the rear tires have a slight heal/toe wear pattern developing on them.  They only have about 5000 miles on them, so I find this puzzling.  I am beginning to suspect a driveshaft balance or runout issue, or an axle or bearing issue.  I am not sure where to turn to have this issue diagnosed.  Has anyone had experience in this area and can give me advice.  I live in Tulsa Oklahoma if anyone knows of a shop with expertise in this area.  Thanks for any assistance you can provide.

Richard

[Mike Shumack]

I experienced that on my pickup truck. It was a u-joint on the drive shaft starting to fail.

[Eric Maclean]

Richard
The frequency of the vibration should be the telling factor as the drive shaft spins at roughly three times the speed of the wheels and usually presents itself at a much lower ground speed than wheels and tires.
On the other hand tires and wheels usually present at or near  50 to 55 mph and again at double that but I doubt you'll ever drive the coach at 100 mph lol.
Remember tire and wheel balance is not just limited to the tires and wheels it includes all the rotating parts such as brake drum or rotors axles etc. An out of balance brake rotor can have the same effect as an out of balance tire this can be caused by a welded balance weight falling off the rotor or rust build up in the cooling fins of the rotor this can sometimes be over come by simply having the wheels balanced on the vehicle where the complete rotating assembly is balanced together on the vehicle .
As for your tire wear it's hard to tell what type of wear you have without seeing it but even an abnormal wear pattern can cause vibration problems.
Even in 5000 miles a tire can pickup a wear pattern but usually there is a mitigating factors such as broken belts or flat spoting caused by wheel lockup / long periods of sitting in one position or even an aggressive tread pattern can contribute to uneven tired wear this is why the manufacturers recommend regular tire rotation.other things such as bent wheels or even bad wheel bearings and of course loose suspension parts bad shocks or alignment problems can cause wear and vibration.
With all that said it's hard to believe you would have a pattern develope in only 5000 miles with out a defect of some sort.
Hope some of this helps
Eric

[Joel Ashley]

The Ventura IV has a relatively short driveshaft.  Though limiting straps prevent extreme angles, it nevertheless can be subject to joint stresses that longer shafts don’t encounter.  Though a bent shaft is arguably less likely, the U-joints are still susceptible to wear, and as Mike alludes to, I’d initially suspect that.  The cupping on a tire will vibrate the coach until the tire is replaced.  The question there should be, “which came first, the cupping or some other terminal drivetrain malady?”.   Cupping probably wouldn’t come first, so even fixing its cause won’t likely resolve the vibration until the tire is replaced.

Our service providers list doesn’t include a nearby option for you that I can see.  If you were out West I’d steer you to Henderson’s in Grants Pass, but hopefully another member here can advise a truck chassis facility within a reasonable drive of Tulsa.

Joel

[Fred Brooks]

  I wonder what the mileage is on the shock absorbers, another reason to cause "cupping" on tires.

[Steve Huber Co-Admin]

Fred makes a good point, especially if they are Goodyears, which I have found are extremely susceptible to cupping. That said, I would be somewhat surprised if rear tire cupping caused a significant vibration that was speed sensitive unless the cupping is severe. My first bet would be wheel related and then drive shaft (but once started, it seems it should continue to worsen as rotation increases). Let us know what you find.
Steve

[Richard Davis]

Yes, Fred, I suspected shocks also and that was one of the first things I checked.  They are Bilsteins with about 35,000 miles.  I took all 4 of them loose and checked for leakage and firmness and resistance of travel.  They all 4 look good.  The heal/toe wear pattern on all 4 driven tires is very slight and subtle.  It is not visually noticeable, but you can feel it when you run your hands over the tread.  It is a saw-tooth type of wear, but very slight so far.  I am suspecting driveshaft or U-joint wear.  Nothing looks bad and I cannot see or feel anything amiss.  Since balancing the tires made no difference, I installed a pair of Balance Master's on the rear.  They made no noticeable difference either.  At this point I just need to find a truck suspension shop with expertise in this area to diagnose the issue.  I was hoping someone out there could recommend a shop near Tulsa, but so far no luck.  I am going to call the shop that balanced the tires to see who they recommend.  Thanks for everyone's helpful comments.

Richard     

[Joel Ashley]

Richard, since by default you are a member there before here, you might pose the service providers question on the proper FMCA forum.  The membership is larger and it would get more exposure.  Perhaps a call to Henderson’s would glean suggestions also.  They’ve always been very helpful even if you aren’t a customer.   Just respect their service advisor’s time.    https://www.hendersonslineup.com/

Joel

[George Harwell]

Richard,
             The Blumenthal company in OKLAHOMA City is a driveline specialty business. Contact 405-236-4800 or 888-236-4800. They are a major business on Western Ave. in OKC.

[Fred Brooks]

    Richard,
Was your coach towed recently where the drive shaft was removed by the towing company. Does your coach have a harmonic disc as part of the short driveshaft assembly? Fred

[Eric Maclean]

Richard
This may sound strange and unrelated but just for snickers go under and check your radiator cooling fan for missing fan blades.
Eric

[Richard Davis]

Fred
The coach was towed and driveline removed, but that was about 3 years ago.  Is it possible they reinstalled the shaft incorrectly.  I visually verified the clocking on the U-joints and it looks correct to me.  I have wondered if they put the driveline halves back together 180 degrees from original thereby messing up the balancing (I do not even know if that is possible).  There is no harmonic balancer on the driveshaft.  I have looked at the driveshaft balancing unit sold by Balance Masters and have considered purchasing one.  Do you know if they really work.  Thanks for your knowledgeable input.
Richard