Mk1 & 2 front suspension interchageability

Not really a new topic as when I asked sometime back I got no replies.

Basically can I fit Mk2 top wishbones to a Mk1 car, the compatibility table I have says no unless you change the uprights.

So is this correct and if so why? Is the taper different or is it a clearance/dimensional issue.

The reason I am asking is that I would like to do a refurb on the front suspension and I can get Mk2 copy parts for half the price of OEM and before you say won’t last as long, with the mileage I do and my age I don’t think that will be a problem.

Thanks in anticipation of an answer this time.

Dave

 

See:

Miata Suspension Interchange - Race & Track Driving (formerly Win HPDE)




I’d rather get refurbished OEM than Chinese copies in this case, not because “they will last longer”, but because they are less likely to break due to some ham fisted welding in Shenzhen. The aftermarket in the US is a lot more sophisticated than over here in Europe. Here, you will rarely know who actually makes the part (who actually makes ILM pattern parts?). Go look at Rock Auto, and you will find several different manufacturers (Beck/Arnley, Moog, Dorman, Mevotech etc), a mixture of Chinese and Mexican manufactured. From the brands, you can do the research, and determine if these are a “good” manufacturer, or one to run away from. The Americans do see the same issues as we do; where previously old and trusted brands have gone broke, or near broke, and then re-emerging with a new owner, but not the same values. In addition, the prefitted bushings to these parts can be highly variable. So, ok, you take these bushings out, and fit with quality Mazda items. But then, you might as well spend the time on refurbed Mazda parts. Lots of issues about the quality of the aftermarket balljoints; it seems buy Japanese or Taiwanese, or not at all.

Pattern parts have a place on my car, but I would draw an arbitrary line on some safety critical parts.

Fitting NB top mounts and springs/shocks though is definitely a great upgrade on the NA.

 

In your previous posting, you did receive a reply, though evidently, not to your satisfaction:

https://www.mx5oc.co.uk/forum/yaf_postst116658_NA-NB-Front-Upper-Control-Arms-Ball-Joints.aspx

 

I also recommend joining miataforum, a far larger forum, which has been running many many years. Its difficult to think of a technical question on the NA MX5 that hasn’t been asked and comprehensively answered over there. Its a bit blinkered to rely on one source of information only.

[quote=saz9961] [quote] Front upper control arms are different between NA and NB due to ball joint taper. Using NA arms on an NB or NB arms on an NA requires upper control arms and spindles to be matching (either both NA or both NB). [/quote]

The requirement to swop arms and spindles I had ascertained from sources other than here as you recommend. The joint taper I suspected was the problem but could not verify, so thanks Saz for pointing me to the facts.

Dave

 

It is difficult to find the actual reason why the MK2 front upper control arm cannot be used on the MK1. The other way around is rreasonably clear, because the threaded part is too short and it cannot effectively be secured. Thread taper makes a lot of sense.

Rear uppers are directly swappable. Front and rear lowers fit pefectly but the drop link fixings are different. MK2 has a twin support whereas the MK1 is a single. General consensus is that the earlier links were the best. Welding on these from OE is very poor to the point that a customer’s car in Belgium failed their equivalent of the MOT where the part was deemed to have been badly repaired. I have a welder so would probably cut off or fabricate MK1 style drop link mounts and use MK1 fixings.

You could probably get the MK1 upright taper machined to the MK2 tolerance and I imagine the quarter inch extra length would then not be an issue.    

Yes machining the taper is an option but I will probably look into replacing the ball joint now that replacements are available from MX5 Parts.

Dave