Rubber vs. Poly

[wantone]

So, If I'm rebuilding a Bronco w/ stock suspension that will see mostly on road w/ an occasional trip to the beach or a mild trail, should I use rubber or poly bushings (rear leaf, C, and radius arms)? I guess rubber gives a softer ride, but costs more, and poly is a stiffer ride, handles better, but costs less. I'm leaning towards poly, but was wondering how stiff it would be. Is the ride change that noticable???

 

[broncnaz]

I dont think you'll really notice any ride or handling differance. Unless all your current bushings are just shot. I prefer the poly C bushings they are just made better they have flanges so the bushing doesnt slip out and probably hold true longer than the rubber will. then I think rubber for the radius arm ends, poly for the trac bar and shackles and rubber for the spring eye bushings would be the way to go. That said my 73 is all poly but my 71 is still all stock rubber.
I also think the poly bushings are a lot easier to install.

 

[blubuckaroo]

I just throw the poly radius arm bushings away when I get the sets. They aren't worth the trouble of putting in. It may not matter if you just stay on the street, but the poly will crack with a lot of articulation. The rubber ones outlast the poly ones by at least 2 to 1. As a matter of fact, I've never wore out a set of rubber donuts.

 

[surfer-b]

I do the same as others have stated, use the rubber on the radius arms, the donuts, and poly for the c-bushings and track bar.

 

[gjrock]

Poly and use rubber on the end of the radius arms.

 

[66Bronco]

So, If I'm rebuilding a Bronco w/ stock suspension that will see mostly on road w/ an occasional trip to the beach or a mild trail, should I use rubber or poly bushings (rear leaf, C, and radius arms)? I guess rubber gives a softer ride, but costs more, and poly is a stiffer ride, handles better, but costs less. I'm leaning towards poly, but was wondering how stiff it would be. Is the ride change that noticable???

Use all rubber except for the track bar.


-Terry

 

[Broncobowsher]

I would actually recomend rubber for the track bar. At least on this vehicle.
Rubber bushings flex the rubber. As long as the travel is minor the rubber will flex. No real movment. When you get into lots of travel then the rubber rips.
Poly track bar bushings are completely different in there operation. Where the inner and outer sleeve of the rubber bushing flex the rubber, the poly is more solid and the bushing rubs the sleeve. Now you have a wear point.

Good rubber bushing in the leaf springs are the same way.
If you tighten the bolt holding a rubber leaf spring bushing in place, then try to move the spring you will feel the rubber being springy and trying to return to the nuetral position. That is why you do final bolt tightening with weight on the suspension. but with poly you have a bushing spinning on a sleeve. Lots of travel will rip the rubber to pieces. Poly will spin on the sleeve.

My problem with poly is the bushing squeak on the sleeve, sometimes with all kinds of lube they still do. I have also had issues with poly wearing itself, but that is generally high travel suspension.

The C's I would probably do poly just to dial in a little more caster.
The ends of the radius arms, I could go either way.

 

[ep67bro]

I have used poly in all my suspensions and never had a problem with them. There may be benifits of rubber but unless you use your bronco daliy or under extreme conditions I dont think you will ever see the differance!

 

[BajaBronco]

My last few sets of urethane C-bushings pushed way too far out on the sides, so I've got with all rubber except for the track bar like 66. I was using black energy suspension brand.

 

[wantone]

Use all rubber except for the track bar.

Sounds like a good place to start. Then if I have any problems, I'll replace what's broken or making noise. I don't like the idea of a noisy suspension.

 

[wantone]

The C's I would probably do poly just to dial in a little more caster.

For a stock suspension, I'd just want the 2deg bushings right? Is there anything else I should know about the caster?

 

[broncnaz]

Do you have power steering? if so then I'd go with the 4 degree as handling will improve. If you have manual steering then yes it would probably be better to stick with the 2 degree bushings. For the best choice you could get the alginment checked to see what the current specs are then decide what bushings you need.

 

[av bronco]

If this thing is going to see mostly street I would take it to a alignment shop and see where your caster is, 4 to 6+ is good on the street, the more +caster
you have the more stable it is on the freeway, most of these things have less then +2 stock. the bad part is if you dont have power steering it gets harder to steer at low speeds with more+ caster.

 

[wantone]

Yeah, no power steering yet. Possible upgrade for the future. I guess I'll buy 2 and then go from there. Since I don't know whats in there now, I have to start somewhere.