mx5cartalk.com

Hi all,

First post in the tech section (probably not the last!)

Car is my partners, my background is Nissans (180SX x 2, 84 300ZX, 89 300ZX TT etc)

Long story short, handbrake failed and NA6 rolled down steep driveway, hit a low wall, caught exhaust tip and pushed muffler into subframe...

Weirdly enough, bent the subframe, pushing the right rear wheel into the wheel arch, but the arms ended up being fine.

Swapped to an NB subframe, but re-used NA upper and lower arms and swaybar links with the NB swaybar and d-bushes.

Went to get an alignment the other day, and he said he couldn't put much, if any, camber on the rear because it's sitting too high. I hadn't noticed but it does seem a bit higher than normal.

Is it due to tightening the bolts (to proper torque spec) whilst the car was still on stands?

I had a jack under the lower arm to raise it up until it lifted off the stands, but presumably this wasn't as compressed as it would be on the ground.

BUT - how are you supposed to get in there with a big torque wrench once it's back on the ground?

I would have thought at the factory torque specs they would still have enough play, but the two alignment guys reckon they both tried to push it down to no avail.

Sooooo... should I be finding a sympathetic mechanic with a hoist that has ramps not swing arms, loosen and try again? Or is the alignment guy not correct here. He suggested 'a set of Kings' but I'd rather find the source than go for a 'solution' like that.

I can attach the alignment readout if that makes any sense...?

Thanks

did you change over to NB shocks/springs also?

from memory the stock NB gear in a NA will make it sit higher (or is it the other way around? haha)

No I didn't use the NB shocks/springs, but given the subframes looked identical except for the added provision for some bracing underneath I don't know if that would make any difference? The only other difference I noted was the exhaust hangers were slightly different...

Frames should be the same, other than little things like what you've said.

I think off the top of y head the NB had about 5mm more track than the NA, but I think that's more in the arms than the mounts.

Tightening while jacked up shouldn't be am issue, after a few days of driving the usual bumps etc from the road will jiggle it where it needs to be anyway.

Does the back of he car look especially tall?

As for camber, have a look under and see where the eccentric bolts are for the rear lower arms.
If the volt head is to the outside of the car it increases negative camber.



Of course, there's always the possibility that the accident bent the subframe mounts on the body and it's not sitting properly.

If you've not already seen it, here's what Miata.net reckons:
'Subframe braces
NA and NB subframes, front and rear, are interchangeable w/ their attached assemblies.
http://www.miata.net/garage/compatibility.html