Wheel Alignment

Have a 2000 Miata SE with 6000 miles. Had 4 wheel alignment done by dealer even though I did not see anything wrong, no pulling or abnormal wear. The dealer did it under warranty. They said my alignment was way off but since they did it at 30 mph I get a shake I did not have before. Any ideas.

Tires will wear into an alignment, to match the suspension angles. Change the angles, and the tires will no longer match. The shake may or may not cure itself as you accumulate more miles on the new alignment. You might try rotating the tires to see if that helps. If the old alignment was bad enough, it may have worn the tires so abnormally that they are effectively ruined, and will need to be replaced. Think of it as an opportunity?

Or they may have dislodged a balance weight. Tell them your problem, and ask them to check your tire balance.

Frankly, a dealer is the last place I'd go for balance or alignment. It's too important on a Miata to be entrusted to knuckle-draggers who don't understand a wishbone suspension.

On all my other cars I would be able to tell if it needed an alignment by the way the car pulled or tires wore, but on the Miata the tires wore perfectly & no pull. Maybe I should have left well enough alone.

I find it very hard to believe that a new car (6K) could be that far out of alignment. Sounds like you mechanic put it out of alignment. Find another one.

Minimizing tire wear is not the only purpose of an alignment. On a Miata, you can actually improve the car's handling significantly with a more aggressive alignment. Light, well-balanced vehicles are particularly sensitive to tiny changes in suspension angles.

It's most likely that the tires are causing the shake. Have them balanced by a shop that uses a hunter 9700 balancer that is described below. The miata or many other cars using similar suspensions are more prone to this when the alignment is correct. The radial tires are not completely uniform, and usually have a 'stiff spot' due to the way they are made. Tires most prone have a visible 'dent' in the sidewall, due to the way that they are made. Tire wear can easily change things. http://www.hunter.com/pub/product/balancer/4159T/ index.htm

<< OTOH, any dealer alignment will be full of random error because the OEM specs have so much slop in them to make his job easier. You could have one front wheel at positive camber and the other at negative and still be in 'spec!' Don't accept such a crappy alignment. A Miata deserves better, and so do you. >>

Is there any standard criteria for who would likely do the best alignment?

Look for a shop that races formula cars. Ask your local club members who

Check with your local/nearest Miata club, see if anyone from there can recommend a shop that knows Miata alignments, and if they will use the alignment specs from http://www.hummingbirds.net/alignment.html .

Rod Gonzalez, Sacramento, CA '96 Montego Blue

thanks for all the advice. I will check with the Mt. Hood Miata Club and see who they recomend.