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BoxheadTim GRM+ Memberand UberDork
3/24/12 10:52 p.m.

I'm trying to change the "coilovers" in my Miata from the NA to a set of used NB ones. Keith's performance projects book suggests to disconnect the top A-arm via the removal of the long bolt. Of course with me being lazy, I looked for an easier way and found one on the Interwebz, basically by disconnecting the lower arm at the balljoint.

Once I had everything apart and got the old strut out, I noticed that the NB strut is just a tad longer so it won't go back in this way, at least not with my puny weight and strength, because I can't move the top arm down far enough.

So that was another 2 hour round trip to the closest HF to get a couple of 21mm sockets. Oh well, next attempt tomorrow...

92CelicaHalfTrac MegaDork
3/24/12 11:04 p.m.

I actually did this today on a friend's car... a spring compressor works wonders. Didn't have to disconnect the top A-arm.

That said, it might have been EASIER to do so, but i'm still pretty new to working on double wishbone cars.

BoxheadTim GRM+ Memberand UberDork
3/24/12 11:09 p.m.

It's actually the top mount that is a little taller. I guess I could try a spring compressor. That'll be another trip to HF then, though...

Keith GRM+ Memberand MegaDork
3/24/12 11:26 p.m.

Spring compressors should only be used away from the car. They're not a band-aid to get the parts into the car. Just do it the right way.

On an NA, the easiest thing to do is pop the upper ball joint off. The bolts on that lower one are more prone to corrosion and I find them to be a hassle to realign. But it won't fit with an NB, which is why the book recommends the big bolt on the upper control arm

If you've got coilovers with an adjustable perch, the cheater method is to drop the perch down and compress the shock. Bonus point if you have AFCOs without internal pressurization so the shock stays compressed on its own. I can yank a set of those out real quick.

BoxheadTim GRM+ Memberand UberDork
3/24/12 11:32 p.m.

The lower ones actually came out OK. Doesn't help with getting them back in . No coilovers, these are standard MSM struts with non-adjustable perches.

EvanB GRM+ Memberand UltraDork
3/25/12 12:09 a.m.

I popped the upper ball joint off to do it when I put the MSM suspension on mine. A long crow bar to pry the arms down when putting the shocks in is very helpful.

ZOO GRM+ Memberand SuperDork
3/25/12 9:58 a.m.

I have used both methods. The long bolt one is now my preferred. Saves time all around for me.

BoxheadTim GRM+ Memberand UberDork
3/25/12 5:11 p.m.

Well, once I put the lower A-arm/balljoint connection back together and took the long bolt out, I was surprised how quickly I could swap out the struts. Oops. No need for crowbars and other implements of torture, either.

Both fronts are in but I guess I better take my wife to our anniversary dinner now .

92CelicaHalfTrac MegaDork
3/25/12 6:07 p.m.
ZOO wrote: I have used both methods. The long bolt one is now my preferred. Saves time all around for me.

We broke the long bolt yesterday.

Keith GRM+ Memberand MegaDork
3/25/12 6:43 p.m.

Wow, that's one rusty car. It's a hefty size - 16mm in diameter, maybe? Might want to stock up on PB Blaster for any further work.

92CelicaHalfTrac MegaDork
3/25/12 6:50 p.m.

Heh, we did. Luckily, AIM Tuning had a replacement, so all is finished and well.

Wish i was installing something nicer than Rokkor coilovers, but meh, not my car.

simplecat New Reader
3/25/12 8:47 p.m.

I can swap out my fronts using the long bolt method in ~40 mins without a lift, it seems fast enough for how smooth it goes.

DaveEstey Dork
3/25/12 8:50 p.m.

This is why I keep Keith's book in the garage with me.

JoeyM SuperDork
3/25/12 10:16 p.m.
DaveEstey wrote: This is why I keep Keith's book in the garage with me.

I have his locost book on the kitchen table next to some seat mounting hardware

BoxheadTim GRM+ Memberand UberDork
3/26/12 12:03 a.m.
Keith wrote: Wow, that's one rusty car. It's a hefty size - 16mm in diameter, maybe? Might want to stock up on PB Blaster for any further work.

I'm really enjoying working on a SoCal car that's lived in the desert here for the past five years.

Bolts actually undo without any help from an angle grinder. A little different than wrenching on a Miata/MX5 in the UK.

BoxheadTim GRM+ Memberand UberDork
3/28/12 12:13 a.m.

And here we go again - three of the new used shocks & springs are in, but for some reason I seem to be unable to get the driver's side rear shock out. I've already done the passenger side - unhooked the sway bar, unbolted the shock, leaned on the pry bar, job done.

Only on the driver's side, I don't seem to be able to push the suspension down far enough, even when I lean on the pry bar with more or less my full body weight. I have a suspicion that the bolt that connects the top A-arm to the upright is hitting the spring.

Any suggestions how to proceed? Disconnect the knuckle from the upper A-arm?

Keith GRM+ Memberand MegaDork
3/28/12 12:46 a.m.

Pull the bottom of the shock free first, not the top.

peter Reader
3/28/12 6:37 a.m.

On the rears, I've always found it dead easy to remove the bolt that holds the rear upright to the upper A-arm (I think you called this the knuckle). Dead easy and then the lower will fall and hit you in the nads. Be careful of the brake assembly, it will fall over and stretch the brake lines.

Edit - Keith is right, pull it out bottom first.

BoxheadTim GRM+ Memberand UberDork
3/28/12 10:20 a.m.

I tried pulling out the bottom first, but that didn't make the shock budge either - for some reason I don't seem to be able to pop the shock out of the lower A-arm. It almost feels as if it is longer than the (also stock) one on the passenger side.

I'm not too worried about stretching the brake lines as I have a set of shiny FM braided hoses to go onto the car, but I'm rather concerned about damaging the ABS wire. I'll try to lever it out again tonight and if not, carefully disconnect the knuckle and see if that helps.

peter Reader
3/28/12 11:28 a.m.

Seriously over muscling this. Just pop out that top bolt. It's not like the front arms where it's seated on a tapered bolt. Unless it's a rusty car.

Hold the hub with one hand, slide the bolt free with the other, throw the bolt into some dark recess of the garage, lower the A-arm until the shock is free, drop shock on foot, lift hub, reinsert bolt, done.

Keith GRM+ Memberand MegaDork
3/28/12 10:34 p.m.

If possible, make sure the suspension is in ride height position when you torque that bolt back up. There's a rubber bushing in there, and torquing it down when you have the suspension hanging means it'll be preloaded.

I never have to undo that bolt, though. Put a long pry bar across the head of said bolt and the end of the inner bolt on the upper control arm. Hold the shock up against the body. Push down on the pry bar. Move the bottom of the shock sideways and drop the shock out. Done. Leverage is your friend.

BoxheadTim GRM+ Memberand UberDork
3/29/12 12:40 a.m.

Yeah, I preloaded the suspension at each corner with a jack before I torqued up the various bolts to avoid preloading any bushes.

I did end up having the disconnect the upper A-arm - once I had done that the rest of the job was really easy, but even with the long pry bar I have I couldn't get the suspension to move down far enough.

When I put the suspension back together I noticed that there is something wrong with the upper A-arm on the drivers side. It doesn't line up with the upright and the upright actually has worn away some material on the inside of the arm. You can see that the arm is not sitting right on the upright on this photo:


And here's what the passenger side looks in comparison:

It's probably not really visible in the photos but the inner bushes (where the arm is bolted to the A-arm) are similarly off center.

It looks like the misalignment is restricting the movement of the suspension, hence me being unable to move the suspension down far enough to pop out the shock.

Any suggestion how I check which part is bent? Looks like I will have to change the upper arm due to the damage, but I'm not sure if that alone is the culprit or if there is more damage somewhere else. Eyeballing the lower and upper arm doesn't seem to help, they look unbent but clearly, at least one of them isn't.

Hal Dork
3/29/12 12:37 p.m.

I am not a Miata person but looking at the pics I would say you have a problem. I don't think the upright (being a cast piece) is bent.

I would say that the outer bushing is definitely shot and maybe the bushings on the inner mounts also. Hopefully the inner mountings are not bent.

I would replace the whole A-arm and bushings.

dean1484 GRM+ Memberand SuperDork
3/29/12 1:42 p.m.

The first photo clearly shows that the bushing in the cast piece has moved / slipped to the right. The metal outer piece of the bushing looks to be about 1/8" away from the cast piece. I would start by replacing it and see if it puts things back to where they belong.

BoxheadTim GRM+ Memberand UberDork
3/29/12 1:56 p.m.

The problem is actually that the upper arm has to be levered towards the front of the car (towards the left) in order to even get it over the cast piece. If they're disconnected the left bottom corner of the arm is actually sitting on top of the cast piece so I suspect that replacing the bushings might not do that much the alignment.

I am currently assuming that the bushings that look like they've slipped to the right (towards the back of the car) basically have been pushed around/out by the bent/misaligned upper arm.

My main concern is that whatever managed to bent this fairly substantial arm might have bent something else, too. I did have a look and didn't find anything that looks obviously out of shape but I'd feel much happier if there is a way I can measure if the arms sit square in the subframe/diff carrier.

Does anybody happen to know if NB arms are interchangeable or the same as NA arms? That might help find a set of good used ones if there's a wider selection. Of course ideally I just get the v8roadster tubular arms but I'm not quite feeling this flush.

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