I've had a chronic vibration in the rear wheels of StaRV II; the onset is sproadic, shoeing up at around 60 moph.

Several attempts at balancing have yielded no cure. The last-done "fix" was to replace the two right rear tires (which both showed signs of cupping at the same area of about 80°), but the vibration is still there. Like before, it comes and goes, and balancing beads didn't eliminate the issue.

The cupping on the two tires, being in the same place led me to move on from the rubber. Although Conrad (the PO) installed Bilsteins all around in '02, the symptoms mimic those of a shock failure. Since the rear brake pads were down to 1/4", I figured I'd replace the shocks as well when I take it in.

Shocks and pads should be here Wednesday.

Stay tuned.

This might sound a little stupid Rusty, but have you ever checked the wheels for perfect roundness?

quote:

Originally posted by Rusty:
I've had a chronic vibration in the rear wheels of StaRV II; the onset is sproadic, shoeing up at around 60 moph.

My P30 does that, too. Right at 61 or 62, a cyclic vibration sets in. Sort of a tramp, going in and out at a little faster than 1 per second. New Bridgestones, Bilsteins and a balanced and rebearinged driveshaft made no difference.

This is not a matter of great concern, since CA has a 55 mph limit when towing, and 60 is about as fast as I like to drive a potato-chip truck, anyway.

quote:

Originally posted by Danny Z:
This might sound a little stupid Rusty, but have you ever checked the wheels for perfect roundness?

Checked for roundness (perfect) and runout - I replaced 1 wheel that had 3/16-1/4" runout a month before replacing the tires.

Hi Rusty, Don't know if this will help you, but thought I would throw it out there for you. Have you ever heard of centramatic wheel balancers? I just went to there web sight, and they make these for motorhomes, looks like around $165.00 per axle. they make them for steer, and both drive axles. Here is the story on these. In the commercial truck industry, weve been using these for years now. Our semi is a 379 peterbilt, we had everything done in the world to the front end you can think of, alignment ,wheel balance, checked for worn parts etc. Could only get around 40 to 50 thousand miles on steer tires. Also had a noticiable vibration around 45 to 50 mph, could actually feel it in the steering wheel. After installing the centramatic wheel balancers, no vibration, last set of steer tires went well over 100,000 miles, and then moved on to trailer. The drive tires on our truck now are over three hundred thousand, and the wear pattern is normal, no cuping on the tires. might be something for you to check out.

Good advice from Bill H on the 60mph. Those darn potato chips crumble into little pieces above that.

The rear tires have balancing beads, and that moderated the problem somewhat, but the vibration still comes and goes.

The balancing beads you have mabee are like what the centramatic does then. We had are wheels balanced with the weights on the rims, and we tried the balancing compound that goes in the tires, none of which worked. We were told by many different shops,truck drivers, and centramatic that the weights only start to work and speeds over 45. The centramatic balancers keep a true balance through out the mph range. I know duel tires on a axle are hard to get balanced, and even harder with drum brakes!!

The balance beads do the same thing as the Centramatic, and are much simpler. Disc brakes all around. Due to the local roads. I could only get up to 65 mph, but the problem is either much moderated or gone. The shocks (Bilsteins) were worn out (60+K miles). Brake pads were 1/8"-1/4".

I used anti-freeze in my new tires when I installed them. About a pint per tire. Works for me.

Anti freeze is also popular as a stop-leak in farm and construction tires. Not being a chemist, I can only guess that it works by softening the rubber.

Actually works just like centramatic, Balance masters, and Equal (the stuff they put in the tires). In all cases the weight shifts to the light spots in the tire, therefore it is an active balancer.