I have a 65mph (and up) vibration problem on an 86 420sel. I replaced the rims and tires with Michelin Harmonies and oem rims from AAArims. The vibration is still present.

So, took it to a GSP9700. Their analysis revealed that 1 tire was bad and two of the rims were "out of round". I left with computer printouts. The Michelin place didn't put up much of a fight and replaced the tire. The rim place is a different story. I faxed them the run out graph that the 9700 did. The total run out was 23 mils. The technician at AAArims (where I bought the rims) said that their "spec" was a maximum of 26 mils and that these rims met their spec. Does that seem right?

So, Mr. Moderator, can a rim that is 23 mils out of round (mounted on a perfect Michelin tire) cause vibration...or should 23 mils be acceptable and be able to produce a smooth ride?

greg

Does anyone have any experience with actual run out data?..and what is tolerable for balancing?

I ran a similar thread a few weeks back and I think our problem was due to a worn wheel bearing. Might be worth the while to get that checked before thinking its the wheels.

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... Kerry

126 tailed by a 203, 129 leading the pack.

go to www.gsp9700.com and do some study. There are many downloadable articles there that give maximum runout specs and all sorts of information. .026" doesn't sound like too much runout to me.

Are you using balance weights inboard AND outboard? If not you will very often have a vibration. Weights ONLY inboard as the wheel shops like to do only provide static balance which means that the wheel does not hop up and down. If you do not have a proper dynamic balance the wheel basically "wobbles" which transmits lots of vibration into the car.

Best of luck,

could be tires out of balance....wheel bearings.....rotors warped....i just solved mine on 1987 420sel....

had guide rods replaced along with assoc bushings and stressed the brake rotors...they were warped....all in all took me a while from doing the front end to where i am at now....but she rides smooth and straight with no vibration at all and smooth braking

lyle

The out of round of the rim can be indexed with the out of round of the tires which will give a better ride, I thought the gps9700 would tell the technician that though.......?
Gilly

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Yep, check out info on the 9700:
http://www.gsp9700.com/pub/features/how.cfm
Look under "Faster Troubleshooting and Repair"

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Dont forget a wheel alignment also. That can go out over a large dip in the road. My 93 400E had all kinds of vibration till I got an alignment only like a degree off from a bad tie rod. All good now. If vibration is center to rear could be flex disks or CV axles.

If you feel it more in the wheel the wheel bearing or alignment is a safe bet.