Vibration

[mjlayton]

Bought a 96 Dolphin 535 last fall. Drove it from Flint, Michigan home to Terre Haute, IN ( about 550 miles).

Very sloppy steering and a vibration that started at 40, peaked at 48, and stopped completely at 55. Replaced the bell crank and had it aligned. Removed 6 double coin tires and installed Michelin XZEs, left double coins on the tag axle. Now it's down to more of a hum at the same speeds. You can feel it in the seat at it's peak. Any help would be appreciated.

Thanks,

Mike Layton

[racer99]

I had a slight vibration on our MH coming back from Fl last year and I blamed it on the roads in ILL> then further along after we got home I winterized and took it for one more little ride before it went to storage and the vibration bothered me that night which made me look further the next day-the 4 bolts on the front of driveshaft were 2 gone- one snug- and one tight-Had a bugger of a time finding the right bolts, had to go to Ford dealer with vin number to get them-When I remove them I made sure driveshaft didn't turn so everything went back together in the same place--Couldn't check it out on road test because cover was on already-find out Apr 1st when we head for FL but I am sure that was the vibration--Rich
pauperspride.blogspot.com

[wolfe10]

Thanks, Rickieblue. Good video.

[Rickieblue]

I agree..most likely is improper driveshaft phasing. To understand phasing of a driveshaft, everyone should watch this short youtube video....Click Here

[11178adm]

check the drive shaft for proper phasing. on the section that has the slip yoke if you sight from one end to the other the caps should align perfectly
if it had been towed and the drive shaft removed some wrecker operators will just separate the shaft at the diff and pull the sections apart and the mechanic at the repair shop may have put it back together wrong also could be a bad carrier bearing, bent drive shaft, bad ujoint or incorrect drive line angles
may not be the problem but it's a place to look at

[mjlayton]

The vibration has the feeling of running over worn out rumble strips at it's peak.

[mjlayton]

The rig is on a chevy chassis, I balanced the front tires when they were all double coin. When I went to the Michelin I moved the front tires to the tag axle. Mechanic checked the u-joints & carrier bearings before any changes were made. If you accelerate out of the vibration, let off the gas, and put it in neutral you will coast back through the vibration as you slow down.

[DSDP_Don]

Mike....Feeling it in the seat of the pants is typically an indication of the rear tires bouncing around or a drive shaft issue.

Did you balance the rear tires when you put them on? Do you know if the Double Coins were ever balanced on the tag? Since the tag doesn't carry as much weight as the duals, an out of balance tire on the tag can tend to bounce around a little more.

[enblethen]

Double Coin are premium tire normally used on many over the road trucks. They have a series that is very good on MHs. They have several 8-19.5 tires which some tire companies do not make.

[FIRE_UP]

What in the world is a "Double Coin" tire?
Scott

[BIKERK9]

If steering still sloppy, highly recommend the "Safe T Plus" steering stabilizer. Life time warrantee and two DIU installation videos on You Tube.

[enblethen]

What chassis is the rig on?
I would be checking the center support breaking on drive shaft.
I would have kept the Double Coin tires. Been running them for years.

[fcooper]

If they are the same size, I'd temporarily swap the tires from the tag axle to the front to see what that does for the vibration.

Of course, it could be drive line related also.

Fred