Polyurethane front end

[cubanmoparnut54]

Hey guys, I am in the middle of rebuilding the front end on my 71 RR. I have ac delco sway bar links and rubber bushings on the sway bar. The rest of the suspension has polyurethane bushings including the rear sway bar. Will it make much of a difference to swap the new front sway bar rubber bushings & links with polyurethane? Thanks

 

[steve340]

The sway bar will be more effective with the plastic bushings as it does not have the "give" that rubber does.
Lubricate the plastic so it does not squeak or wear out prematurely.

 

[Don Frelier]

Short term I doubt you would notice any difference.
Perhaps after a few years of use you might.

 

[Kern Dog]

The main difference is in the immediate response since the urethane is harder to compress.
Sway bars and strut rods are the only places that I use it. For bushings, it does increase vibrations for very little improvement in performance.

 

[ckessel]

Urethane does not last very long on the lower control arm. Gets beat out pretty quick. Not resilient enough like rubber. Other areas are groovy.

 

[snakeoil24]

Rubber = less headaches

 

[cubanmoparnut54]

The main difference is in the immediate response since the urethane is harder to compress.
Sway bars and strut rods are the only places that I use it. For bushings, it does increase vibrations for very little improvement in performance.

Interesting. This thing was very sloppy and all over the place even after an alignment. I welded the plates on the LCA's and installed the sleeveless bushings. I'm curious to see how the car will handle when I'm done with it. Tubular uppers with urethane bushings as well.

 

[cubanmoparnut54]

Urethane does not last very long on the lower control arm. Gets beat out pretty quick. Not resilient enough like rubber. Other areas are groovy.

I thought it would last longer. Will it make it handle better?

 

[ckessel]

Debatable. You can get Delrin/Nylon from a couple of suppliers. They require different shafts that are greasable. Less deflection out of them but...they transfer more NVH[ noise, vibration, harshness] to the car. I got some from Firm Feel for my 65. Have not used them yet but I know the tradeoff compared to rubber which I'm fine with. I have Urethane for the uppers, sway bars and rear springs. Again I'm fine with the NVH tradeoff as I'm shooting for max handling with oe based stuff.

 

[RJ Squirrel]

I put poly bushings in my leaf spring hangers and shackles- big mistake can not get them to stop SQUEAKING

 

[ckessel]

My 65 already had the urethane on the springs. Pulled them out of the old springs, cleaned/greased them and the new springs, slid them home. Never heard any squeaks from them on the old springs when driving the car.

 

[RJ Squirrel]

Did you use the silicone grease? I did that plus good locking nuts on the shackle bolts to leave them loose enough for room for the grease, lasted 150 miles and started squeaking again.

 

[cubanmoparnut54]

Did you use the silicone grease? I did that plus good locking nuts on the shackle bolts to leave them loose enough for room for the grease, lasted 150 miles and started squeaking again.

I greased the bushings with the supplied grease thoroughly, I am doing this on a budget so I have to source each part properly. Strut rod bushings are prothane as well. Lower control arms were welded together with boxing plates as well as Tubular uppers & stock torsion bars (for now). New idler arm as well as ball joints & tire rods. New manual steering box. I live in los angeles at the moment and drove the car every other day for the time being. What kind of handling can I expect?

 

[cubanmoparnut54]

Did you use the silicone grease? I did that plus good locking nuts on the shackle bolts to leave them loose enough for room for the grease, lasted 150 miles and started squeaking again.

The rear leafs have new rubber bushings which I will leave in place. Rear sway bar has polyurethane bushings and links.

 

[ckessel]

I used some Marine spec silicone grease recommended by Tom Condren? from his book. Have had it sitting for many years and finally put it to use. Not sure what the PO used but it was still working fine.