1987 300sdl - car was driving perfectly.

Left front tire replaced - blow-out while doing 5-10 mph- replaced with spare immediately. Care drove perfectly with spare.

Both front tires replaced using same rims at local tire shop. Front end vibration at 55-60 mph. The 'jiggle' is barely noticable at lower speeds. It can be felt in the steering wheel.

Rear tires replaced as well. Problem persists.

All tires rebalanced on a Hunter balancer. Twice. Tires were only very slightly out of balance first, perfect second time. Problem persists.

Back to local tire shop- removed front tires and replaced with used tires for comparison- problem persists.

Had front end checked- ball joints replaced and aligned.

Borrowed two rim/tire combinations from a friend and put on front- problem persists.

Problem seems to be worse when it is colder outside. It feels exactly like a knot on one of the tires, but no matter what I do the problem doesn't go away. As long as I don't drive in the 55-60 mph zone it is hardly noticable.

I don't know what to do. The car used to drive so great and now it has the &)(*^&_ vibration. I have tried to correct it to no avail. Is it possible that the rotor(s) are warped? Any other issues? Any tests to diagnose where the jiggle is coming from? Could a bad strut cause this?

I am going to try another set of wheels/rims from another friend. I thought that the tire shop may have overtightened the rims and warped them, but so far haven't been able to pin down the problem.

Also, the 'jiggle' seems more pronounced at certain points as the steering wheel is turned. For example, half turn to the right seems worse than in straight line or to the left.

Any suggestions appreciated.

What make and model tires were they?

These vehicles are very sensitive to out of round tires. The "typical" American tire is out of round by 1/8" or so and the M/B is a bit intolerant of that.

Drive the vehicle on a perfectly smooth road at 6-7 mph.....steady. See if you feel you head bobbing up and down slightly. It's not objectionable but you'll notice it if the tires are out of round. You need a perfectly smooth road.

The alternative is to setup a pointer or a piece of chalk on the surface of the tire. Rotate the tire to find the point where the tire pushes the chalk furthest away. Then rotate the tire 180 degrees and measure the gap between the chalk and the tire. This is the amount that the tire is out of round. If it's 3/32" (est.), or more, it's probably too much for an M/B.

I suffered with out of round tires on all my American made vehicles for years. They really don't care much. But, the M/B does and I run Michelins on it for that specific reason.

all of what brian said. i am a michelin man too.

but it seems a puzzle that it remains a problem (on the left front?). so that leaves the rotor or brake disc which seems very very unlikely to have been caused by the blowout.

unfortunately i have no other ideas.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

check you steering dampner (horizontal shock absorber between the front wheels) rubber bushings wear out easy. Also, check for any cracked or broken grease boots in yr suspension (excessively worn bearing?

There is a slight bobbing at 6 or 7 mph.

Are the cars sensitive as to the rears being out of round also? The tires are bfg's. I'd hate to replace all 4 of the practically new tires but I really do hate the wobble.

I'll check the steering damper and related components.

Thanks a million for the suggestions and I'll repost as I progress.

..........as I suspected.........

Problem is all too common.........most tire manufactures.......BFG, Goodyear, Firestone, et al........produce crap.........and people buy them because they are cheap.

tires have good tread maybe you can sell them to a friend who doesnt drive on the highway much.

sorry

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Are all of the Michelin tires 'round'?

Again, Thanks.

Well, I can't say that anyone has run every tire that Michelin produces, but, the general consensus from most Michelin users is that you get what you pay for.

Personally, I've never been able to detect an out-of-round condition on the Michelins, and, therefore, you can probably conclude that they are round to less than .062".

No tire is perfectly round.

A longshot perhaps, but check the front wheel bearings.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

michelin out of round yet. i have prob had dozens of sets.

usually if i have any trouble with them it is from ham fisted balancers!

i had one blow out once but that was cause it was low on air and i didnt spot it.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Oh, they are out of round......alright......it's just that you can't feel them.