Fly or Why? Polyurethane Bushings and Mounts
By Rick Reimundez
I’ve heard that replacing the rubber bushings in your suspension, motor, and tranny mounts with polyurethane pieces makes a huge difference in performance without lightening your wallet much.
The basic idea as we understand it is that poly bushings flex less, which tightens up the suspension. Less flex means more proper movement, or in the case of the drivetrain, more power transferred to the pavement. In both cases you get a tighter driving car and better, more confident handling.
A number of manufacturers make replacement bushings and mounts for a ton of applications. Prothane and Energy Suspension are two of the more well known ones. We hear that upgrade is often made in concert with other suspension upgrades as well.
So do poly bushings offer real performance gains, and if so, is the comfort hit worth it? Let us know in comments.
Prothane [Corporate Site]
Energy Suspension [Corporate Site]
October 12th, 2007 at 11:53 am
I replaced all of my suspension bushings with poly bushings. I noticed better handling in my 98 Dakota. BTW, my Dakota can corner like you wouldn’t believe with my Hotchkis kit. Any way, the only downside I have is the squeaking. Poly bushings squeak unless you can lube them. The factory control arms don’t have zirk (sp?) fittings so I can’t grease them. I thought about drilling a hold and installing one, but haven’t tried it. Now on the sway bars, I don’t have this problem.
October 12th, 2007 at 5:37 pm
Squeaking is the only complaint I’ve ever heard from Poly bushings. They are also often difficult to install depending on what you’re starting with. There are graphite impregnated varieties that are supposed to prevent squeaking but for the most part, if you don’t already have zerks, you’re sol.
October 12th, 2007 at 10:01 pm
As I recall, with regards to the squeaking issue, you want Poly for compression applications (Body bushings, etc) but not for rotational apps (Control arms and such).
I’ve personally used them for pretty much everywhere, but they can definitely stiffen up the ride, and it may well become too harsh for some. And of course, there’s the potential for squeaking.
Supposedly the Graphite impregnated ones don’t squeak nearly as much.
October 12th, 2007 at 10:56 pm
In terms of the comfort hit, I was actually thinking more about the issues of vibration, which is more of an issue with motor and tranny mounts than suspension bushings. My 2000 Golf had a poly dogbone motor mount that replaced the factory rubber pieces. They were two pieces that sat at opposite ends of what looked like an aluminum dog bone. I ended up swapping one of the rubber pieces back in because the buzzing from the engine making its way into the cabin was just unbearable. With one poly and one rubber piece I got rid of some of the vibration, at least it was bearable, and I still got some improvement in the way of less motor movement.
It was at that point in my customizing plan that I came to the conclusion that I ‘ruined’ my car. I decided then that I would modify with what I actually used my car for - and not just purely for performance. Today, my car is my daily driver, so everything I do to it to make it perform better, handle better, etc. is done with every day comfort in mind. It still rides a lot stiffer than stock, but that I’m ok with, but I can cruise on the highway approaching triple digit speeds, and it’s like I have the cruise set at 55.
When I have a track day barn stormer - it’ll have poly all around, cause I’ll have hearing protection and a helmet, so comfort won’t be the goal. But if I have to live with it everyday fuggedaboudit.
What other thoughts you guys got? Come on, three responses? I can’t believe no one else has an opinion on this. (gosh, I hope we don’t just have three readers
)
October 12th, 2007 at 10:58 pm
Hey Vincent -
Tell me about your Hotchkis kit? What do you have installed? Is it lower, or stock ride height?
I’m thinking of installing the Hotchkis sway bars on my (wife’s) Trailblazer. It’s already got Ground Force lowering springs and Bilstein’s all around, but I’m not happy with the lean.
October 13th, 2007 at 8:49 am
I have a full energy suspension kit on my DD and hate it with a passion. For a full on track car it’s fine but for a DD the squeaking will drive you to the edge of insanity. No matter how much lube you put on the bushings they wil still squeak. I blew the suspension apart and relubed it 3 times trying to kill the squeaks and no dice. Next time I’m due for an alignment I’m blowing everything apart again and going back with rubber.
Abe
October 15th, 2007 at 8:36 am
Hey Rick,
The Hotchkis kit is a 2/3 lowering kit. I have the full kit which included new coil springs in the front and new leaf springs in the rear. The front sway bar was replaced with a larger one and a new rear sway bar came in the kit. I didn’t have a sway bar on the rear. It also included new Bilstein shocks all around. I love it. It does stiffen the ride a lot, but that is what I wanted.