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Posted by: MikeM Aug 17 2015, 01:40 PM

Hi all...many of you have helped me try to find a vibration/shimmy in my car in past posts. Today as I was studying my records for this car, I looked at the last alignment printout. It shows NO front toe. As in - 0.12 degrees. Both sides. I think spec is like 20 minutes, or about 0.33 degrees.
Could this be the cause of my shimmy? What does NO TOE feel like?
Thanks,
Mike

Posted by: SLITS Aug 17 2015, 01:49 PM

The car will wander on the road ... straight line stability.

We ran the race cars with no toe in to gain a tad bit of speed as with toe-in it could scrub some speed off. For better turn in in corners we would set toe out, but again this could scrub speed.

Posted by: jd74914 Aug 17 2015, 01:49 PM

I'm not sure what stock spec is, but it is definitely not 10 degrees. It may be 10 minutes (more precisely arc-minutes) which corresponds to 0.17 degrees.

Generally less toe makes a car feel more unstable.

Posted by: MikeM Aug 17 2015, 01:52 PM

You're right of course. Not 10 degrees, I think that's 10 minutes.
Mine is actually -0.12.

Posted by: MikeM Aug 17 2015, 02:05 PM

Jeff Bowlsby's specs say 20 min. plus or minus 10 min.
20 Minutes converts to 0.33 degrees.
Mine is at -0.12 degrees.
Experts, should mine be adjusted? Or are we talking about insignificant amounts?
Mike

Posted by: SirAndy Aug 17 2015, 02:17 PM

I run 2 mm toe out in the front and 1 mm toe in in the rear

Measured at the edge of the rim on a 15" wheel, no idea what that translates to in terms of degrees ...

Posted by: Dave_Darling Aug 17 2015, 02:19 PM

What are you doing with the car? Track, autoX, street driving, other?

What does the negative number mean? Toe out? (If it's a "toe IN" measurement, negative would be toe out.)

For autoX, I'd pick a little toe out. For the street, I'd pick a little toe in. For the track, possibly zero like Herr Slits said.

--DD

Posted by: Mark Henry Aug 17 2015, 02:22 PM

Toe would not cause the shimmy.

Unless it was camel toe....

Posted by: MikeM Aug 17 2015, 02:37 PM

The car is a street only car. Yes, I assume the negative number means its toed out.
If that number.-0.12, wouldn't cause a shimmy/vibration at 30 and 60 then I'm pissing in the wind...again.

Posted by: DBCooper Aug 17 2015, 03:31 PM

I worked in an alignment shop when I was young. No, toe by itself won't cause shimmy, that's true, but it will exacerbate anything loose in the front end and let it vibrate in a harmonic, or shimmy. For example with wheel bearings a little loose the zero toe will let the tires track freely, so any bearing movement will let the tires hunt just a bit from side to side as the slack in the bearings allows, and at certain speeds you'll get a shimmy. In that same car with all else equal and a good bit of toe added the bearings will be slightly stressed from the bit of tire scrub that was added, which will put pressure on the bearings and you won't get the shimmy. It'll still happen occasionally when you hit a ripple in the pavement or whatever, but it'll be occasional.

Look, the only reasons for shimmy are something being loose, out of balance or not rolling true. You can guess and replace parts, and invite other people to guess all day long, but until you get someone involved with the car who understands alignment everything you do will still just be guesses. Go to a GOOD alignment shop, they're the people who deal with everyone's "shimmy" problems, and have them diagnose it for you. No guessing.

Posted by: MikeM Aug 17 2015, 03:37 PM

DB...good points and I thank you for them!!
Problem is there are no good 914 alignment specialists in my city.
If there was, I'd be there!! Maybe I should have the toe adjusted so that there is some toe in, see what happens.
Thanks,
Mike

Posted by: MikeM Aug 17 2015, 06:59 PM

Bump please....

Posted by: johnhora Aug 17 2015, 07:14 PM

Stock specs....

Posted by: Mark Henry Aug 17 2015, 07:15 PM

QUOTE(MikeM @ Aug 17 2015, 05:37 PM)

Posted by: johnhora Aug 17 2015, 07:23 PM

Mike....pm me your email and I will email you a home alignment guide...
Really any alignment shop should be able to do the front...it's just a McPherson strut...nothing complicated....the rear is a little quirky...I understand some having a problem with it...

Have you checked all of the suspension mounting point bolts etc for correct torque...has the car ever been wrecked in the front....any signs of metal fatigue or cracks in the front trunk floor at the mounting points???

Posted by: MikeM Aug 17 2015, 07:51 PM

Nope...no Canadian Tire for me.

Posted by: DBCooper Aug 18 2015, 08:03 AM

You don't necessarily need a 914 specialist, just someone well experienced and good, a true alignment specialist. Believe me, if they're experienced they've seen it all. One of the oddest ones I remember was a bad ball joint that worked well except at one particular angle, when it would bind. That threw out its alignment from the other wheel and produced a shimmy until the ball joint got past that angle and moved freely again. Usually it's play in some part, this one was the opposite, a lack of play.

There's no real point to that story except that after you get past the obvious things like wheels, tires and play in the suspension things get more complicated, so the more experience looking at it the better. And to be clear, I wasn't the alignment guru, I was the kid who put the cars on the rack and set it up for him, then watched.

Posted by: MikeM Aug 18 2015, 08:14 AM

I think I'll take it back to him and get him to dial in some TOE IN. Right now it has slight TOE OUT. Nothing to lose.

Posted by: Geezer914 Aug 18 2015, 12:30 PM

Take it to a good tire shop and have them speed balance the tires. Any weights missing? Double check the wheel bearings.