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Posted by: MikeM Aug 10 2011, 12:44 PM

Hi guys..I've posted about this before but still haven't cured it.
I have a vibration/shimmy at 30 mph and 60 mph. Seems to be the whole car that shimmies as opposed to just the steering wheel. I have balanced several times, switched wheels front to back many times, and recently tried a friend's wheels with brand new tires with always exactly the same vibration. I have adjusted wheel bearings, tightened and loosened them, same problem. There is NO play in the ball joints or tie rods,I've had the car aligned and I've had wheels repaired.
What should I be looking at in the back of the car? Seems likely that something is wrong back there.
I don't really want to throw a bunch of money at replacing parts unless I know it will fix it.
BTW...car is a 74 2.0 liter.
Any suggestions appreciated....
Mike

Posted by: SirAndy Aug 10 2011, 12:50 PM

- Trailing arm bushings or ovaled mounting hole.

- Cracked suspension console.

Jack up the rear and see if there's any side-play in your trailing arms ...

Posted by: MikeM Aug 10 2011, 12:55 PM

Thanks Sir Andy...I'm not sure how to check side play in the trailing arms....
Mike

Posted by: r_towle Aug 10 2011, 01:19 PM

jack up the rear so that the trailing arm is hanging free and grab the wheel and shake is in every direction.

Rich

Posted by: MikeM Aug 10 2011, 01:28 PM

Thanks Rich...

Posted by: Ian Stott Aug 10 2011, 02:12 PM

I had a slight vibration, tires were balanced right to zero not just in the green on the balance machine and my rims are straight and true, got the concentric centering rings from Chris Foley and problem was solved. If all of the above posts/suggestions check out OK maybe they would help.

Ian Stott
Moncton
Canada

Posted by: underthetire Aug 10 2011, 02:29 PM

Check your CV's. Those will cause it if coming loose.

Posted by: MikeM Aug 10 2011, 02:35 PM

Checked CV's...all are super tight. Thanks.

Posted by: MikeM Aug 10 2011, 02:41 PM

Does anyone know the proper size for the rear hub centering rings for Mahle wheels? I'm going to try to find them locally...Chris Foley is a loooong way from me.
Mike

Posted by: r_towle Aug 10 2011, 02:56 PM

get a set of calipers and measure the hole in the wheel, and the diameter of the hub...that should show you the difference.

I believe that Foley is the only one who makes them and keeps them in stock...

Go to a high end wheel shop...one that has alot of bling wheels.
They know where to get these things.

rich

Posted by: r_towle Aug 10 2011, 02:57 PM

have you ever had a four wheel alignment?

Rich

Posted by: MikeM Aug 10 2011, 03:03 PM

Rich...yes, I had it aligned by a reputable guy. He did a nice job, the car is straight and true. BTW, I checked the trailing arms...nice and tight with no play.
Not sure what else to do at this point. I have tried other wheels with the same result but I guess that doesn't completely rule out the need for hub centering rings...
Mike

Posted by: Drums66 Aug 10 2011, 04:48 PM

.....Are lug nuts torqued?.........say what?

Posted by: 9146986 Aug 10 2011, 06:01 PM

Has any of the tires been plugged?

Wheels/tires balanced on the car?

Venting clearance on rear calipers?

Adjusted slack in front wheel bearings?

Rear wheel bearings?

Shocks?

Rotors?

Posted by: kg6dxn Aug 10 2011, 06:16 PM

If it happens at 30 & 60mph, that is harmonics from the wheels. Get the concentric rings or balance all 4 wheels.

Posted by: jmill Aug 10 2011, 06:19 PM

Can you clarify this whole car shimmy? Does it happen at one certain engine RPM as opposed to 2 speeds?

Posted by: jk76.914 Aug 10 2011, 07:07 PM

Mine was doing something kinda similar. It was pretty good when I started out, but as the suspension warmed up, a similar shimmy started. Mine was in the front, at about 70 mph, but curiously the steering wheel didn't shimmy, only the body. In my case, the strut insert was shot. I figure that maybe as the shock warmed up, what little damping it had left it as the oil thinned. Then it was susceptible to minor imbalances that normally would have been damped out.

Maybe no connection, but thought I'd throw it in.

Posted by: MikeM Aug 10 2011, 07:27 PM

Guys....thanks for all the suggestions. I'll try to answer some of the questions that have come up.
I must admit, I don't know what venting clearance on calipers is...
On car balance is something I have not done. There is a shop in town that used to do that so I'll call them.
The shimmy is not rpm dependant, it is speed dependant. I can feel it around 30 mph and then I can really feel it at 60mph.
I have had the wheels balanced several times, but have not purchased the hub centric rings from Tangerine Racing.
Thanks, and keep it coming!!!
Mike

Posted by: MikeM Aug 11 2011, 04:21 PM

Hi all...I have ordered the hub centering rings from Chris Foley,who is a super nice guy BTW, and I'll report back.
Cheers,
Mike

Posted by: 76-914 Aug 11 2011, 07:24 PM

I chased this same thing for over a year. One place even trued the tires. I was sure the ball joints and tie rods were fine. I was wrong. After rebuilding the front end it was perfect. I was relying on my front end experience with heavier cars. Mistake.