Honda CRX Forum banner
1 - 20 of 28 Posts

·
Registered
Joined
·
1,061 Posts
Discussion Starter · #1 ·
Hey, can someone add to the FAQ where to add polyurethane bushings to your suspension, and where not to? I think it would make life easier. :)b
 

·
Administrator
Joined
·
16,557 Posts
Well we can just put it here and then I'll put it in the FAQ.

Poly is ok:
Shift linkage bushings
Engine mounts
Steering rack
Front upper arms
Sway bar mounts and end links
Lower control arms to shock forks
Upper shock mounts (top hats)
Front crossmember/radius rods

Poly is NOT ok, use OEM or Mugen hard rubber:
Rear trailing arms
Lower control arms to body (front & rear)
Rear lower control arms to trailing arms
Compensator arms
Rear upper arms

The problem with poly is that it lacks the elasticity of rubber, so when it is forced to deform it tears. I don't have to tell you that a broken bushing is a bad thing.

On a related note, I think the poly ball joint boots, like the ones that come with the Energy master set, are junk. Some people don't think they're so bad, but they're a PITA to install because they don't have a groove for the retaining ring, and there is no inherent advantage in using poly for a ball joint boot. The boots just hold the grease in. If you need to replace a ball joint boot, most of the time you need to replace the whole ball joint anyway.
 

·
Registered
Joined
·
6 Posts
I have an 89 DX and installed poly on the front lower control arms, the rear lower control arms, the trailing arms, the front swat bar, and added an ST rear which comes with poly bushings as well. The difference was amazing. Some guys fuss about the real trailings arms when they put poly there. You do have to lube them up with silicone grease so they don't squeak, but they do help positively locate the rear suspension on a variety of road surfaces and under braking and acceleration.
The next time you have your hands on a set of rear trailing arms out of the car, try to wiggle the bushing. You should be able to move it 1/2 inch or so. Imagine what kind of suspension geometry changes this allows. By all means, if you enjoy bump steer in the rear suspension, keep it stock. If you like they components to retain their design parameters under dynamic conditions, poly is the logical choice for an enthusiast's car. These cars are 20+ years old by now, and the rubber there wasn't all that stiff to begin with. 20 years later, it probably is far worse.
This is not an opinion. This is based on science.
 

·
Administrator
Joined
·
16,557 Posts
You're not the first person to try to make this argument, but it's not correct. There is no science in binding up the suspension. Poly bushings are designed not to deflect, which is fine if something is only rotating on one axis, but the rear trailing arms and lower control arms especially must rotate and pivot at the same time. You can easily see this if you push the suspension through its range of motion. In addition to pivoting up and down, you'll see the rear trailing arm rock in and out a little bit, as the unequal length control arms force it to. Likewise, the mounting points for the control arms and compensator arm on the trailing arm follow an arc through their range of motion, and that forces the arms to deflect laterally. Poly just does NOT work there. If you need proof, here's what happens to poly where you shouldn't be using it:




If you can't tell, this is worse than a worn rubber bushing, it's almost like not having a bushing there at all. If you refuse to use rubber bushings, then use something like MFactory spherical bearings, but don't use poly where I told you not to.
 

·
Registered
Joined
·
961 Posts
wow a picture is worth 1000 words. i take it this is from personal experience. so from what i have read, order on the POLY bushings that are listed in the OK section, and if re-vamping entire chassis order new oem bushings for the others. Next question are POLY ok for body mounts and tranny mounts? or are they an important enough bushing to mess with
 

·
Registered
Joined
·
149 Posts
There's a reason he's site admin and gets the big bucks..... :)b
 

·
Registered
Joined
·
345 Posts
I hope that this is the best place to ask this instead of just starting a new topic. But what bushing is this exactly and what do you guys recomend Poly or oem rubber? I had been told to replace them like a good four month's ago thankfully never got around to it...



Based on what you all have said it seems OEM rubber would work best here...
Can someone clarify this for me? thanks
 

·
Banned
Joined
·
347 Posts
I see a lower ball joint. And as Jfro mentioned, if you have to replace the ball joint boot, then it's likely time to replace the whole ball joint.
Ball joints were also a recent topic on here and the gc was go OEM for the best quality.
 

·
Registered
Joined
·
253 Posts
SleapFast1 said:
So am i understanding Correctly that there is no full kit that includes both the Poly bushings needed and rubber ones since poly is used some places and rubber in other places??Whats the best way to purchase??
I believe you are correct.
The only kits I see are the full poly kits.
So you would have to replace your bushings as needed. Hopefully your car isn't like mine, where each bushing needs to be replaced :(
 

·
Registered
Joined
·
15 Posts
Damn it, unfortunattly with all of us Rex owners our cars are damn near twenty years old so yes i see just about all of the rubber needing replaced. Mugen needs to make a poly/Hard rubber KIt!! whats wrong with these companies...?! Thanks for the info Guys
 

·
Registered
Joined
·
9,843 Posts
That's just it, these cars are 20 yrs old, and there isn't enough of a market for these companies to tool up and produce these.

There are no kits that combine poly and rubber in all the needed spots.
 
1 - 20 of 28 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top