Rear shackle bushings Rubber or Polyurethane ??

[HotRod20]

Opinions requested please,: using S/S springs, what is the census for shackle bushings, rubber ? or polyurethane ? and why you have a preference. Trying to decide what to install and would like opinions of those who made a choice for either one. This is going to be mostly a bracket racer, with occasional street time. Thanks to everyone who comments,
HotRod20

 

[BergmanAutoCraft]

Urethane is a better choice provided they are lubed properly. The rubber ones are super soft and don’t hold the correct shape against the shackle.

 

[CUDA69]

Polyurethane, still good after 44,000 miles and 20 years of hard use (autocross, 1/4 mile and road courses).

 

[Locomotion]

With only occasional street use, consider poly or even aluminum spring eye bushings for the front as well. Soft rubber is wasted motion & energy and most locations benefit from the firmness. Transmission mounts, however, should not be solid/aluminum, but good with poly also.

 

[72bluNblu]

If you can weld you might also consider a set of spring sliders. They can be used in the stock location with a pretty easy to fabricate bracket.

 

[HotRod20]

Wow, very cool,.. nice work. Installed Poly bushings ..thanks

 

[French demon]

Is a special tool required to replace the shackle bushings (rubber or polyurethane)..?

 

[Car Nut]

Is a special tool required to replace the shackle bushings (rubber or polyurethane)..?

Not really, I’ll beat mine out with a hammer and an old screwdriver. Bought new springs with rubber bushings, I went with poly bushings from PST.

 

[French demon]

Hello Car nut
I don't want to replace my springs, but only the bushings. Will upgrade to poly too.
Are poly bushings easy to go in? Just screwing the shackle nuts? Or do I have to press them into the spring and the hanger before?

 

[junkyardhero]

Is a special tool required to replace the shackle bushings (rubber or polyurethane)..?

that depends... do you consider beer and making up new swear words special tools?

all kidding aside, you can get the new bushings in with a vice, jack screw or even a really big C-clamp

use LOTS of lube. helps install and with the squeaks.

 

[Car Nut]

Hello Car nut
I don't want to replace my springs, but only the bushings. Will upgrade to poly too.
Are poly bushings easy to go in? Just screwing the shackle nuts? Or do I have to press them into the spring and the hanger before?

Even easier, they just pop out with a press much easier.

 

[Car Nut]

all kidding aside, you can get the new bushings in with a vice, jack screw or even a really big C-clamp

Thinking of it now, I did use a big C clamp to press them in.

 

[French demon]

In theory, replacing the shackle bushings seems to be an easy job.
Theorically...
Today, I began the replacement
The 54 years old bushings are dry, stiff, blocked by rust and have been very hard to remove. It took me two hours to completely remove the hangers, shackles and of course the bushings (and in accordance with Junkyardhero, with a lot of swear words ).
Some of them were surprisingly in good shape, but the others were totaly cracked and/or destroyed.
Left side spring bushings, those on the right side are a little better :

Tomorrow, I'll clean all the parts, especially the shackle studs : the original grease, still present, has turned into a hard deposit covering the studs.
I'll take some photos....

 

[French demon]

Today
Dirty parts

Really dirty. Old and dry original grease

After some cleaning

New polyurethane bushing pressed in. I used a vise, but it has been hard to install full way. Even with some prothane grease.

It's easier on the spring leaves. Large C-clamp, and grease.

Next step : reinstalling the shackles

 

[French demon]

Not a fun part, the shackles studs are very hard to press into the bushing (and here, under the car, I do not have a vise)
Anyway, with a little persuasion they went in and it's over...

Now, it’s time for a good beer