Coil spring changeover

So this is my first technical post. I was told to post this because someone may not know how or whay this happens........so here it is !

when I bought my T, it came with an air bag rear suspension. Here is a pic of the frame that Clark took ( that I snagged here on the HAMB ) during construction. You can see that the air bags mounted on the trailing arms and fit into a bracket on each side of the frame. The bags were Air Lift units.




I found that I could screw up a steel ball with a gl*** hammer. I over inflated the bags and ruptured one while i was out in the car. Hated the bill to get home on a roll back so coil springs were the answer.

First thing to think about was springs. I had no idea what worked and what didn’t. I ended up talking to my buddy and he says I got a set you can have. They came from a 76 4 cyclinder Capri. And to help things along, he had already cut one full wrap from the coil springs. The price was right !
We determined that the rear valance of the car was to be 15 1/2 inches off the ground. We used another set of air bags to get the rear valance to the desired level. Our measurements showed our spring had to be 9 inches at ride level. Our springs brought us to about 10 inches. We retrimmed the spirngs by 1/2 wrap and put them back in the car. The springs which measured 11 inches high with no load provided a static ride height of 9 inches. There is 4 inches in between the cups but the rear end will contact the frame snubbers with 3 1/2 inches of travel.
My buddy gets a lot of dumpster s**** from his work. My coils springs cups came from the s**** heap. We had thick wall mild steel tubing in 5 inch diameter. We also had 4 stainless 1/4" plate that was cut in 6 inch circles that were also drilled with a 1/2 " hole in the middle. These became the caps for the cups. There was nothing special about welding these other than it had to have great penetration. so here are the cups on the springs that will go into the car.



These became the bottom cups




We decided to use the same frame brackets that had been built into the car for air bag suspension.


This is the top view of the air ride bracket. There are 4 pilot holes that will be the mounting holes for the new coil spring cups. The holes in the middle were the schrader valve hole in the middle and the mounting holes on each side. The brackets were already placed almost dead over the mounting plates that were built into the trailing arms. We started, thinking we would use a 2" x 2" square tubing to mount the top cups. We also thought that we should be using something on the top of the tubing as a mounting plate. So we used 1/4" plate and made mounting plates and welded it to the tubing. The holes in the mounting plate would allow us to bolt the crossmember to the bracket. This allowed a return to air bags if we so decide.
In this photo, the marked hole shows the dead center spot on the trailing arms.



After putting the bar into the brackets several times, we determined that the cross member was not a good idea. It would contact the axle on a heavy bump. After a lot of conversation, we decided that we could cut the ends off the bar and use individual cup caps. So we did



So the top cup, spring and rear cup are in place.

We are not completely finshed with the rear suspension. There will be another installment on the shock mounts as well as the panhard bar.

I drove the car for the first time on the new suspension this last Friday. What a difference. I’m not sure which of the three changes had the biggest effect but a combination of three has produced a real fun ride that is very quiet.
Next tech will be how to clean the underside of your car prior to posting pics

 

Looks good man.
You could even install overload bags inside the coils if needed.

 

Nice and clean. I'm liking those trailing arms. Kinda look like the "truck arms" used on 67 Chev trucks. How does it handle???

 

Clark built using that truck arm style. With the changes, it is really like a go kart...........a really loud, cool, go kart

 

what is keeping the springs in place when the suspension is unloaded?

 

Shocks have 3 1/2 inches of up travel so they are the main thing keeping the springs in the cups( 5" dia x 4 inches high). At the bottom of each lower cup is piece of 1/4 " steel
( 1/4" x 1 1/2" x 5") held in place by the bolt that holds the cup in place. That piece of steel goes over the spring on one side so the springs are bolted into the bottom cups

 

I may have to get some measurements from you on that one. Might have to build my own. If your's works, I may as well try to copy it.

 

Nice tech, love the white suspension pieces.