Frame / Springs: Rear spring change out for '61 Hawk

[Al Kurz]

All. I have a '61 Hawk 4 spd. Years ago the springs were sagging and I had them re arc'ed. Since then, my rear ends sits about 2" high. I want to ask the forum if anyone has any experience replacing the leaf springs with a lighter fiberglass spring. I figure if I am going to replace the rear springs, I could reduce the rear sprung weight a bit and improve handling a smidgen. Also, any suggestions for aftermarket shackles and delrin bushings to further tighten up the rear sway and wiggle? Many thanks. Al K

[chet445]

I replaced my rear springs with new ones purchased through SI. I am satisfied with the new springs and the car sets level as intended. My complaint is with the new shackle bushings as they allow the springs to shift ever so slightly and you feel the effect. I would love to put in the Delrin bushings if I could find a person willing to cut them; they would be cut from 2" stock according to a post I received. Not sure this helps but this has been my experience. Chet 445

[DEEPNHOCK]

Changed the rear springs on John S's '59 Hawk as they were sagging a bit.
Ordered new HD Eaton Detroit springs that were 1" taller than 'stock'
They were perfect. Nothing like new spring steel.

https://www.eatondetroitspring.com/findmyvehicle/

[JoeHall]

All. I have a '61 Hawk 4 spd. Years ago the springs were sagging and I had them re arc'ed. Since then, my rear ends sits about 2" high. I want to ask the forum if anyone has any experience replacing the leaf springs with a lighter fiberglass spring. I figure if I am going to replace the rear springs, I could reduce the rear sprung weight a bit and improve handling a smidgen. Also, any suggestions for aftermarket shackles and delrin bushings to further tighten up the rear sway and wiggle? Many thanks. Al K

How far have you driven the Hawk since the springs were re-arched? They tend to drop fairly quickly, once placed in operation. So quickly, I don't care for them. I have had excellent results from SASCO (now SI), and Dave T-bow. I always buy the HD version, because the standards were too wimpy for me. For now, you could put 100 pounds or so of weight in the trunk and drop that 2" down easily. I am gonna try delrin bushings next time around, especially in the frame bushings, but hoping not to have to deal with that anytime soon. They are a royal PITA to get out. The ones in the springs only take about five minutes though.

[Mike Van Veghten]

To actually answer the original question -

I think a couple of people have looked into the plastic spring thing, including myself.
So far, for one reason or another, everyone has stuck with OEM style springs.

You need to watch for the different ways that the sprig connects to the body. Some springs just don't look up to the task without breaking. Some springs have an aluminum fitting as part of the eye, that sandwiches the spring. This would be a good method. Looks bad, but is stronger than many other spring eye methods.

Another hint of back when I looked into this, many of the fiberglass spring manufacturers...have gone out of business.

Good luck in your search.

Mike

[Al Kurz]

All. thanks for all the tips. A few answers.

Chet: If I ever get another lathe, (on my list since my last move) I will be happy to make a set up. Unfortunately, I have don't have access for the time being. So it seems that I may just go with the original rubber. Probably nothing wrong with that.

Joe: I had my springs adjusted 25 years ago and I when I first got them back, I thought they would sag. Never did. In fact, I left 200# of sand in the trunk when I worked out of the country for a few years and when I took the sand, out, the springs popped right back. I guess that the problem with good quality work!
As for replacing the frame bushings, it was not hard for me. After I cut out the old bushing using an inside hack saw (carefully) I used an old mariner's trick and soaked the new bushings in a container of sub zero boiling refrigerant. They shrunk enough that I could slide them in. Pro tip. You only get one shot to get this right so you need to be lined up and sure it will work.

Mike: thanks for the tips on the fiberglass springs. I am not interested in testing, just getting my car working better and better. I will stick with HD steel springs.

[bensherb]

My springs weren't sagging and the rubber in the bushings was good, but I replaced the bushings with ,a good design, delrin bushing set I made. The stock bushings only contact the shackle with a very thin wall tube. That tube had distorted allowing the thin stock shackle to "Z" and shift from side to side. To get the stock bushing out of the frame I heated the rubber until it easily pushed out then kinked the outer tube with a chisel and drove it out. My new bushings fill the gap between the spring and shackle to fully support the spring laterally. I made new shackles that are twice as thick that fit the bolts snuggly further curbing possible lateral movememt, I also made the shackles 1" longer to raise the rear of the car as I wanted a bit of rake. It now handles very well with no rear end wallowing.

[Jeffry Cassel]

Replaced my rear springs with Detroit- Eaton springs last year (64 Hawk) Totally satisfied. They arrived before the promised date ,had bushings, and fit. That doesn't happen too often thesedays. Hint --change one spring at a time.

[JoeHall]

All. thanks for all the tips. A few answers.

Chet: If I ever get another lathe, (on my list since my last move) I will be happy to make a set up. Unfortunately, I have don't have access for the time being. So it seems that I may just go with the original rubber. Probably nothing wrong with that.

Joe: I had my springs adjusted 25 years ago and I when I first got them back, I thought they would sag. Never did. In fact, I left 200# of sand in the trunk when I worked out of the country for a few years and when I took the sand, out, the springs popped right back. I guess that the problem with good quality work!
As for replacing the frame bushings, it was not hard for me. After I cut out the old bushing using an inside hack saw (carefully) I used an old mariner's trick and soaked the new bushings in a container of sub zero boiling refrigerant. They shrunk enough that I could slide them in. Pro tip. You only get one shot to get this right so you need to be lined up and sure it will work.

Mike: thanks for the tips on the fiberglass springs. I am not interested in testing, just getting my car working better and better. I will stick with HD steel springs.

25 years ago, but how far has the car been DRIVEN since the springs were re-arched? My experience, even new springs, front and/or rear, will settle in nearly an inch within the first 1000 miles.

[Al Kurz]

Joe: About 25 K I think. Again, thanks all for the help. Al K