Control Arm Bushings: Polyurethane or Rubber

[1970FuryConv]

Due to lack of funds, college tuition due for a kid, end of year, etc, I have been reading old Mopar magazines as a way to stay connected, but not spend any money. For control arm bushings, has the problem with the poly bushings deforming, that Steve Dulcich describes in this article, ever been corrected. See the black magic marker bracketed area. High Performance Mopar, January 1994

 

[thrashingcows]

Personally I will only run poly bushings on my sway bars, the rest I want to use rubber simply to try and maintain as quiet a ride as possible.

 

[CanCritter]

..lm with thrashing..rubber for me...found poly a little to stiff on a truck l did..like quiet and smooth

 

[Davea Lux]

Poly bushings are probably ok on the sway bar. If you run poly on control arms and strut rods, you car will be very tight on corners but ride like an ox cart. Poly bushings were a good option for high performance road racing but lousy for anything else. They also tend to squeak and and transmit every road noise imaginable.

Dave

 

[CBODY67]

From the start of the "poly craze", promoted by magazines with advertisers of such (it seems), after consideration, I came up with a "mix" orientation. For suspension parts which just pivot (as in GM or other upper control arm bushings), then poly might help locate them better for a little better handling precision. But for bushings which absorb road forces, as in the lower control arm bushings (typically GM and such), then rubber is best in those locations. I suspect that all replacement bushings are of higher durometer (stiffness) than the OEMs might have been, too. Front leaf spring bushings should be rubber, but the rear shackle bushings can be poly, as with the mounting pads for the rear springs-to-axle housing.

Key thing is that there are places in the suspension and body structure that NEED to have absorptive capabilities so that these forces are not transferred to places they were not designed to be (in the chassis and/or body).

On the cars with link-bolt sway bar attachments to the lower control arms, POLY finds a great place there. Supposed to make the sway bar act 20% stiffer, than with the stock rubber bushings from the factory. Moog sells them in the complete kit (blue bushings), which seems a bit softer than the white bushings which GM sold for the WS6 '79 Firebirds.

Enjoy!
CBODY67

 

[70bigblockdodge]

Rubber on the pivots, poly on the sway bar. The tension struts is a toss up, it will make sharp bumps in the road (like uneven pavement) hit harder, but it will stabilize LCA under hard braking reducing wander.

 

[Turboomni]

I put poly on everything when I built my Omni glhs. It rides like a steel wheeled skateboard because of it and the stiff autocross coilover adjustable Koni shocks. But it handles well with NO lean. You really have to be in the mood to drive though. I would advise the sway bar only with poly on a C body. It will really help the cornering without hurting the ride.

 

[1970FuryConv]

Thanks for all the answers. If I decide to rebuild the front end on my 1970 convertible, I'll keep your suggestions in mind.

 

[Gerald Morris]

Thx for the data here. I like the idea of poly bushings for my swaybar links, but want NO part of anything that would just TRANSMIT IMPACT IMPULSE to the frame! These WWI cratered paths they misname "streets" in southside Tucson barrios wreak unholy vengeance on my suspension repairs as it is....