I’ve determined that at least the rear suspension bushes on my '03 Mk2.5 need replacing, might as well do the whole lot whilst I’m at it.
Question is should I go with the original OEM ones (rubber I assume) or ‘upgrade’ to poly bushes and if so which ones, I understand that the different colours mean different hardness, is that right, if so where can one get a colour chart ?
I love the ride quality and handling as it is, I would not want the ride to be any harsher or noisier. I’m not doing track days etc, I just cruise, pootling around country lanes with the top down and a bit of Mike Oldfield tinkling away is perfect, not thrashing it around seeing how fast I can get round the lanes.
Another vote for OEM , yes I have fitted a full set recently and my reasoning was that if Mazda spent a lot time and research in deciding they were right for the car then that was good enough for me …
There are a number of poster on the Mazdamenders board and their Facebook site who have changed the complete set of bushes.
It is a long job and the general feeling of the guys was that it was not worth the effort but the designer of the MK1 advised owners to change the bushes at 60,000 miles.
A good few of those used either OEM or the aftermarket rubber bushes from MX5parts.
Some of the people who used the polly bushes use then on their daily driver and advised they were happy with the results, others found them noisy and need lubed.
I would not change then unless there was play in the bushes or the rubber was disbonding from itself.
As always your money, your choice but ask there or on NUTZ as there appear to be more users that change them on those forums.
Both MX5parts and Autolink(UK) offer Mazda OEM bushes, other suppliers my also supply.
From time to time the Mazda dealer can be less expensive on some parts but that does vary depending on the dealer or if you may have a discount with a specific dealer.
Most dealers will try and price match the delivered price.
There are US dealers that might be worth a try. I think though Mazda doesn’t sell the bushes as a set, instead, you have to look up all the part numbers, and there are a lot. Maybe someone on a forum has listed out the part numbers needed for a “master bushing set”.
I think the answer with bushes is. if it ain’t broke don’t fix it especially if you enjoy the general feel of the OEM rubber bushes. The problem with rubber bushes, OEM or MX5Parts(IL Motorsports), only 2 choices I am aware of, is the price of the parts as well as hassle of fitting.
I would probably buy good wishbones and refurbish rather than change bushes. Please note that the usual best method of refurbing wishbones is powder coating which generally requires curing heat that will melt/damage the bushes left in place. Apparently there are colder than standard cure powder coat processes that do not destroy the bushes. As far as I know Removed rubber bushes cannot be effectively refitted.
Someone asked why OEM is recommended - quite simple really considering the original question - it is by far the best solution.
Yep. If you read up on the R&D of the MX5 the project designer stated that the only mod he would carry out at 60,000 miles would be to change the suspension bushes. Not because of pending failure but because they will have lost their original suppleness.
Poly bushes are great for track duty but original age old bushes are really not far behind unless they have failed. That is quite rare in any case due to the very light weight of these fantastic cars and the fact that the suspension works fantastically well in any case.
The point being that you can install harder bushes as a mod. but the thing of doing that is you could be changing hardened bushes for harder so not improving the original exceptional suspension dynamics at all.
Of course it’s “Horses for courses” but have a read and a think before spending loads of money on changing perfectly serviceable components. Honest. I’m not making this up.
Lets be clear, the 60,0000 mile claim came from Norman Garrett the Third, in his MX5 tuning book, paraphrasing a question he as “one of Mazda’s top suspension engineers”. Norm then goes on to show how to change bushings with some old bits of pipe, a MX5 tiedown, bolts and washers. Norman wasn’t the guy who designed the MX5, nor likely the engineer he apparently spoke was the guy who designed the MX5 suspoension. He might have been one of 100 suspension engineers, doing bits and bobs.
He’s a Georgia Tech graduate who shows up on the Miata project I guess around 1985, with some authors describing him having substantial motorsport experience. I’m not sure how. He describes himself as a “studio engineer” on the project, other sources describe him as a packaging engineer. He’'s become well known in the MX5 world as he founded the Miata Club of America (before the car was launched, astute move) and founded Miata magazine (the whole club/magazine story went a bit south later on). I guess if he didn’t write the book etc, he would have been less remembered.
Anyhow, I’m not sure “60,000 miles” means anything. You might notice an improvement at 40,000. Over the years, I have seen plenty of MX5s, with lots of miles, and the bushings are all in good condition . It varies from car to car. My S-Limited 2 has lead a hard life, for 270k kms. The bushes, all original, are “fine”, in terms of condition. No rattles. If I changed them out; would I notice the difference? Maybe, maybe not.
