Strange Vibration from front wheels.

[phn]

Hello,

I have a 1972 Opel GT with aftermarket 15" TSW alloy wheels on.

Between 60 & 80 mph a really bad vibration comes back through the steering wheel. It only occurs at these speeds.

It feels just like when the wheels are out of balance. However, I have had the wheels balanced 3(!) times by 3 different reputable garages and the problem is not any better.

Can anyone think of anything that could cause such a vibration that is not coming from unbalanced wheels?

Thanks in advance,

Philip.

[opelwasp]

Get a front end alignment. The tires may be trying to roll at different angles and it can cause all kinds of weired things to happen.

[coolchrisp]

You might want to check the wheel bearings to, just jack up the front end grab the tire and try to woble it back and fourth. im not sure worn wheel bearing would cause so much of a shake but more of a pull.

[guyopel]

Your tires can be the problem ( Road Force Vari . ) this is uneven tire sidewall stiffness .
Check your tie rods for wear ( inner and outer ) these adjust and hold your toe in alignment correct .Your front end bushings need to be checked also front shocks . HTH

[jordan]

All ball joints should be checked, upper and lower balljoints that are worn can cause a vibration camber-wise. Extremely worn bushings in the front end can make enough slop to cause a vibration, also the steering rack bushings. Lots of stuff to check, but I would start with a front end alignment

[kwilford]

Sounds like a typical case of "GT/Kadett" front end shimmy. The lower A arm bushings are too compliant (soft) and even with the tires balanced, the front end vibrates. It was particularly bad until Opel changed the design midway through 1971 on the GT when they went to a thicker inner sleeve in the bushing (the bushing material became thinner, and hence less pliable). But worn bushings also behave the way you describe. OEM bushings are rubber, and new ones will help, but after-market polyurethane bushings are much better at controlling the shimmy. Worn upper bushings can have the same effect, as can worn ball joints.

[phn]

Thank you for alll these helpful repies - I will certainly get this checked out when I get the chance. It would improve the car 100% to get rid of the annoying wobble!

Philip.

[phn]

Is it a big job to fit new bushings? Can it be done easily by a DIY mechanic, or should it go to a garage?

Philip.

[soybean]

There is a couple of good threads on this subject. One is Here. There is another by
Stanley P called "Get rid of the shimmy" Do a search in the suspension forum and you should find it. If it's bushings, OGTS has everything needed to rebuild the whole front suspension. Hth, Jarrell

[hrcollinsjr]

If it's bushings, OGTS has everything needed to rebuild the whole front suspension. Hth, Jarrell

OGTS is also good about supplying an instruction or tips sheet with some of the parts that are less than straight forward to install.

Harold

[phn]

Thanks for the extra info!

I have used Opel GT Source before, and have also found them to be helpful - it would be hard to run my car without a shop like that - there aren't many GT parts stockists in the U.K.!

Philip.

[kwilford]

Can anyone think of anything that could cause such a vibration that is not coming from unbalanced wheels?
Philip.

Another thought, although a bit out there. Did you check your brake rotors for roundness? I don't mean run-out, as that would cause brake pulsing, but "out of round". Try using a run-out gauge on the outer edge; perhaps they are out of round or perhaps missing a piece or something that would cause an out-of-balance. I think that some shops can balance wheels on the axle, so you might also try that to see if they can see if the combined tire/wheel/rotor/hub/bearing is in balance.

[phn]

Thanks for the additional information!

You people certainly know your Opels inside out! I love driving my Opel, but unfortunately I'm not much of a mechanic!

Philip.

[gr_diver]

I have had the same problem before, and the problem was not balancing the wheel-tyre pair itself. I had the tyres balanced/rotated whatever possible, but with the wheels off the car, on the special machine.

Then I found a garage that could balance wheels on the car. It was a kind of machine that the operator sat on it like a horse's saddle. This cured the issue I had been fighting for some months... He even balanced the wheels with the cosmetic rings on. he told be that this way the whole rotation assembly is balanced not just the wheel-tyre combination.

Of course this kind of balancing is only recommended for front-end, since rotating a single wheel on the rear end might cause some serious damage to the differential... Or so I was told...

[namba209 (R.I.P.)]

When I was a teen-ager, working in my Uncle's garage, we had a "Bear" wheel balancing system that balanced the whole rotating mass that way. There were 4 rings on it, two would add or substract weight, the other two would move the weight around the wheel. IIRC we did all 4 wheels but had the rear completly off the ground. We'd also have the doors open so we could see the smallest vibes being transmitted out to the doors. I've always wished the shops would use that system today.

[Dmcbrass]

The best way to balance narrow wheeled tires is on the car. In the old days " ", we balanced the front tires by putting an electric driven wheel against the tire, (car jacked up of course). There was a spring loaded sensor that would be placed under the car (against the frame). This sensor supplied a signal to a meter that read the amount of unbalance (actually an arrow pointing to red, yellow, green) and fired a strobe light that the mechanic aimed at the side of the wheel. This allowed the mechanic to determine the amount and location of wheel weights to add to the rim. The rear tires were balanced the same way, except the car's drive train was used to turn the rear tires. This method took care of all unbalance including rotors, hubs, drums, etc. Unfortunately, this only allowed for single plane balancing (the static component). With the advent of wider rim/tires, it is now more important to also remove couple. That's why you now see weights being added to both sides of the wheel. The vibration you described is always caused by either bad tires or unbalance in the tire/rim/rotor combination. Wheel alignment will not cause vibration by itself. It will eventually cause odd tire wear that can then cause vibration. Likewise, loose front end components don't cause vibration. They simply allow the source of the vibration (probably tire balance in your case) to be amplified. Even an extremely well balanced tire will cause unacceptable vibration levels if there isn't enough dampening in the front end due to worn frontend parts, shocks, etc. I had a 1974 Manta that I could never get the tire balance good enough until I replaced the front shocks.

[opelgtworld]

that the operator sat on it like a horse's saddle...

Yeeehaaa!

[gr_diver]

Yeeehaaa!

That's right opelgtworld, that's the kind of machine I meant!

By the way, is that Alfa "Spider" yours? Sweet machine!

[opelgtworld]

That's right opelgtworld, that's the kind of machine I meant!

By the way, is that Alfa "Spider" yours? Sweet machine!

It is not my car.
I have a prettier, sportier, coke bottle shaped German car...

[zhaniac]

sup man .i had the same problem with my corsa b .after fitting my 15 inch a line mags
after getting it rebalanced 4 times and taking it to an opel dealership they couldn't find the problem. Untill one day when i decided to check my brakes in front and found that my spickerings in front was damaged and it was plastic i replaced it with alluminuim ones and the vibration was gone. just check yours if u have spickerings .hope it helps it did for me.