I recently purchase a MX5 - 2.5model on 05 plate, 41000 miles from a Mazda dealer. Car came with a new MOT. Has been re-inspected by the Mazda dealer to no avail. I have also had a separate equivalent MOT check at another MOT station, without the Cert.
I’ve also had the wheels balanced - twice.
Yet still the whole car wobbles whenever I go over a bump, dip, manhole cover or any form of road deflection at all speeds.
However, at all speeds on a smooth road surface the steering is straight, unless a slight camber, with no steering wobble at all.
It has been suggested by the 2nd garage to have 4 wheel alignment to see if that cures the problem. But reading the various posts this is not the best way, but the full geometry seems to be the only one.
The supension needs a thorough check for any play or softness in the bushes and joints. Use a pry bar to be sure. Check the anti-roll bar mountings and drop links. The steering should also be checked, track rod ends, broken/loose rack mountings etc. Try changing the wheels back to front in case one of the wheels is distorted.
Thanks for your reply. Wheels were swapped after the second balance. I understand your comments regarding the bushes, but would they have been checked at both MOT’s.
Mine is not a MK1 but I had a slight wobble on mine on those seams with patch and repair and the back used to twitch which was slightly unsettling.
Like the above poster Blink sorted mine with a full geo setup to their optimized settings “road warrior”. Interestingly there were only two things out the camber at the front drivers and the rear toe was out but it feels so much more planted now.
It would depend on the tester, it does take time. Each bush/bearing needs checking with a pry bar for any play and or perishing/softening of the rubber. You need to be methodical and meticulous if you are to isolate the cause. The suspension bushes may be worn or may have gone soft or perished, giving rise to movement which should not be there. Pay particular attention to the lower and upper ball joint. Do not forget the anti-roll bar mountings, bushes and drop links. Good Luck!
Have you had an MX-5 before this one? If not, then maybe you’re dismayed at what all Mk1s and Mk2s do to some extent, which is shudder a bit over some particular bumps that cause the body to twist. Do the dashboard, steering wheel and side windows seem to shiver a bit like a jelly over some bumps? That’s the famous ‘scuttle shake’ common in open-top cars whose body structure isn’t very stiff. One very effective way of reducing it, given that your Mk2.5 will already have a good number of underside braces, is to fit the Performance 5 Sportdrive reinforced frame rails. They stop much (but not all) of the twist.
I remember driving a brand-new Mk2.5 from Mazda UK’s own press garage in 2004 or thereabouts, having not at that point driven any MX-5 for around six years, and being shocked at how shuddery the structure felt. When you own one, you tend to get used to it but the car is significantly nicer when it does it less.
All this assumes that all four dampers are in good shape. It’s possible that one or more have failed or gone weak despite the low mileage. Worth a check. Any signs of fluid leakage?
Firstly, seems this may well be the characteristic ‘Scuttle Shake’ as you descibe.
The second garage could find nothing wrong with the car even tho I highlighted my concern. I will consider an alignment check. I am aware of two garages that do the ‘4 Wheel Alignment’, but yet to locate a garage for the full Geometry setup, in Dorset or surrounding areas.
This is my first MX5. I also drive a VW Tiguan and a Ford Focus. I did have a BMW Z3, 2.2 Sport, but that was a totaly different piece of kit.
Four-wheel alignment is the same thing as a full geometry set-up. Or should be.
My memory of the BMW Z3 is that it, too, had hardly the stiffest of structures although probably better than an MX-5’s. The Mazda should handle much better and more predictably than the BMW, though, not least because it has proper double-wishbone rear suspension rather than high camber-change semi-trailing arms.