87-93 Rear lower control arm. Help identify!

ryankenn

New Member
Jun 4, 2007
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87-93 Rear lower control arm. Help identify! *NEW PICS*

I recently purchased an 88 Coupe with what was advertised as a Coilover suspension. I didn't really care as I was more concerned with the condition of the car. Well I've got it now, and it rides extremly rough. I want to change the spring rates of the setup, but I can't determine what make it is. The front are definitly true coilovers, with Koni adjustable and blue springs.

The rear however, is a standard setup, with a HD lower arm with sway bar mount and adjustable perch, blue springs and a Koni shock. It looks very much like the Maximum Motorsports setup, but the lower arm is a box type tube, not round tube like they show on their site. I also found at my oil change with Ford, that the rear springs have no isolators, top or bottom, which explains the squeaky ride.

Can someone identify these for me so I can order some lower rate springs. Side: when I take the tires off, will the spring be stamped with their current rate somewhere? I'd like to know so I can adjust when I order.

Thanks,
Ryan

rearlowerjn9.th.jpg
 
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Sweet

That's what I'm hoping. Then I can order a set of specific rate springs for the front coilover from MM and get a lowering spring set for the rear, and raise the perches to get the height I want, while still using the factory isolators.

I havn't done a hard search, but do companies ( Eibach, H&R etc etc ) make specific rate springs for the Coupe lighter ass end?
 
Only Problem

I face is the the rears are a standard spring, and the fronts are coilovers. So I need to be able to purchase only the rears of all these sets, then get some appropriate hypercoil ones to match up front.

Ryan
 
Well

I talked to MM today and they indicated that if its using Koni 30's ( which mine is ) it is actually a Griggs setup. He also indicated that having coilovers up front, with a standard Lower A arm out back is an odd choice, and no matter what I do with the spring rates, the shocks even set to minimum will larger contribute to the rough ride.

Now I'm going to pull the car apart and get the spring rates from the front and rear and see if Griggs has a recommendation for me to make the car smoother.

In the end, this is a GR40 Track setup and I may end up selling the whole thing and starting over, as the more I read on the Koni 30's the more I think they were intended for racing, not for daily driving.
 
I actually have a cheaper solution. Just get different shocks. The Koni 30s can be used with any control arms, not just Griggs. I have Competition Engineering 3 way shocks on the back of my car and it says to only use them for race applications. I still use them anyway and I don't race. We could easily swap shocks and I have Steeda control arms.

From what I've read over the years on these and other forums I get the indication that plenty of people mix coil overs up front with standard control arms in the rear. One of the main reasons they go to a coil over is to reduce weight on the front end economically.
 
Koni's

Do the Koni 30's have a reputation of providing a harsh ride, even on the lowest adjusted setting? I've never really experienced a "harsh" ride that was mainly due to a strut, even a stiff one, like I have right now, so I'm hoping when I get the springs out the rates are as high as I think they might be.

Here are some pics from tonight. The guy from MM told me I should be able to get the spring rates off the springs, but neither was legible. The fronts may have had it at the top, and the rears did have it at one point, but the metal on metal had worn it off. Here's the pics.

The car.
img6780il4.th.jpg

The front suspension. I loosened the spring right off to try and read a stamp on the bottom, but it wasn't there, or it was at the top.
img6783qc0.th.jpg

Rear as it was once I lower the axle.
img6784xp3.th.jpg

If you notice in the previous photo, once down the rear spring fall out, as the bottom perch is like a hat sitting ontop of a nut. Its not secured at all and it all basically falls right out. Is that right!!!!?? I don't get it.
img6785fp9.th.jpg

Closeup of the lower arm. I'm confident it is a Griggs setup, so I've contacted them for some tips.
img6787mh6.th.jpg

Ryan
 
Well, the arm may have originally been in another car.

You'll have to contact Griggs about whether the spring perch should be easily removable or not. I don't think that's the problem. Even with a removable perch the spring should still stay under enough tension to hold the perch in place on top of the adjustment bolt even with the shocks fully extended. If you're going down the road and hit a really big pothole the possibilty that one or both springs could pop out exists with the way the car is set up now. That's not the way it's supposed to work. Either the spring is too short or the shock extends too far. You should need to remove the shock to get the spring out.
 
also check to see if you axle is a 7.5 or 8.8, it should be an 8.8 but with those finned rear drums it could be a 7.5, i've never seen the finned drums on an 8.8..you can decode the axle tag pretty easy, it is located on one of the differential cover bolts

~Mark~
 
I hope its 8,8

I'll verify but this is an original 5.0L car, which I understood all came with 8.8's. When I was in the process of buying it, I did get brake prices from Canadian Tire and they offered a "premium" drum that was finned for double the price of a standard one, so that could be what's on here.