Replacing Rubber A-arm Bushings

[jkolk]

Is it possible to replace the old rubber with new? Are they available? Can they be installed?

Thanks in advance.

[Wavey]

Not a DIY peoject. The rubber is bonded to the hole in the control arm and to the center bushing, so that it twists with arm movement. Someone (I think Smart Racing?) offers a service where you send your arms in and they install new bushings, but it's pretty pricey ($400?) Other options are new arms ($$$), polyurethane bushings (have to be custom fit, tend to be squeaky) or Elephant Racing's PolyBronze bushings (expensive, custom fit, but work really well). Unfortunately no cheap or easy fixes. A search will yield more information.

[Rot 911]

Wavey pretty much covered it. I went with the Elephant polybronze.

[88911coupe]

I was wondering about this myself and have a question. Does the fact that the original rubber is bonded to the inner and outer sections serve any purpose? It seems the alternatives would allow the two parts to move a little more independently of each other but I'm not sure if that's good or bad or irrelevent. Also, why do these require "custom" fitting, are there substantial variations in the two pieces.
TIA

[RallyJon]

The stock rubber doesn't slide like poly or the Elephant bushings, it deforms to accomodate the few degrees of rotation.

Having seen the pics people have posted of older rubber bushings deformed to one side, I wonder if the rubber is even firm enough to handle larger torsion and sway bars without degrading quickly?

[MotoSook]

The tolerance of the A-arm ends and the carriers (front and rear) for the A-arms is not that good. The rubber is more forgiving, so the tolerance is not critical.

The polygraphite bushings have some elasticity, but not nearly as much as the rubber bushings. They will make up for the poor tolerance, but forcing them on can sometimes lead to squeeks. Fitting them (machining the OD of the bushings relieves some of the compression on the A-arms. The bushings are not perfect out of the box, not perfect in the sense that they don't fit perfectly in the not-so-perfect A-arm carriers and on the not-so-perfect A-arms. So sometimes a little has to be shaved off!

One trick that I have yet to try is to machine a groove on the ID of the bushings, in the middle. I've heard this prevents the squeeks. In my mind, it makes sense.

Fitting them is not a great science, and there is enough slop in the suspension to make up for some less than ideal methods.

Here is my method. I do the same thing for the rear with a modified springplate (part of one) as my lathe fixture.

Front Suspension R&R with polygraphite bushings ala Souk!

[MotoSook]

Originally posted by RallyJon
The stock rubber doesn't slide like poly or the Elephant bushings, it deforms to accomodate the few degrees of rotation.

And we worry about a few tenths of a degree of suspension setting when on the alignment rack


It's a wonder our cars ever travel in a straight line or turn with any urgency with all the rubbery stuff involved in the suspension...rubber bushings...rubber tires... Ha!

[Superman]

I disagree. There is an inexpensive, DIY repalcement method. If you don't have the cash for the Elephant units, there are at least a couple of hardnesses of rubber/plastic replacement bushings. I used the "street hardness" which is like a hard rubber. I cut the OD of the bushing, but I don't think that's really necessary. I say goop a bunch of silicon grease on them and mash them on. that's what Paul did, and I think it works just fine. I also cut grooves on the ID of the bushing and installed zerk fittings, but I think this is similarly unnecessary if you use silicon grease. I don't think they'll ever squeak.

Burn the old ones off. Outside.

[MotoSook]

Jim, I'm not sure to what you disagree. I am all for the low cost polygraphite bushings. Heck, even a belt sander can come in handy when fitting them...you just gotta know what not to screw up. I would put my polygraphite bushing car up against a "more expensive" bushing car any day...provided we come up with a good performance test. But then again, my car isn't so slow on the track...with it's cheapo bushings

[RallyJon]

Rubber and polyurethane (or polygraphite) have completely different properties. Rubber compresses and deforms, poly displaces and flows. It really amazes me that people think they can be used interchangeably.

[MotoSook]

OK. I'm confused now....

...maybe I helped confused myself, with the attempts humor (but I did use the smiles)

[safe]

I'm in the process of installing Elephant PolyBronze right now.
They are very unforgiving for missalignment, mine is binding right now.

I will try to chim the mounts in line or I will have to send Chuck an order for his control arm mounts...

[randywebb]

Souk - who's Jim in your reply above?

Was it a reply to Superman?

[MotoSook]

Yes, Randy.

[MichiganMat]

Are you sure you guys are talking about A-ARM bushings and NOT spring-plate bushings? There should be no need for any kind of burning or pressing of rubber bushings on the a-arms, mine pulled apart just fine. The rubber is a tight fit, but its not bonded to anything.

I replaced mine with poly-graphite and the results were mixed, no squeeks but plenty of popping as the bushings shifted around in the mounts. A little JB-weld has shut them up, no problems. I used a dremel on the ID to open them up a bit to let them breathe, and had to machine a bit on the OD of the rears to fit in the crossmember.

Dig right in my my friend, there is nothing to fear but fear itself.

[MotoSook]

Mat: I believe we are talking about A-arm bushings (see topic title )

The rubber bushings are vulcanized onto the A-arms....and I use a torch to heat the A-arm...it'll smoke and sizzle, then I stick a screw driver between the bushing and the A-arm and it slides right out. It's terrible smelling, so don't do it in a small enclosed area.

[MichiganMat]

Souk: yeah, oops, I worded it wrong. Huh, thats strange because mine were not vulcanized at all, came off perfectly clean.

[MotoSook]

It's possible, with age, that the bushings broke free. All four...maybe someone went Dukes of Hazzard airborne with your car at some point and the suspension moved more than it is typical, so the bushings lost their grip on the A-arms. Heeee Hawwww!!!!

[juanbenae]

Originally posted by safe
I'm in the process of installing Elephant PolyBronze right now.
They are very unforgiving for missalignment, mine is binding right now.

I don't get what you are getting at? you would really have to misalign them to get them to bind. i pretty much threw mine at the front of the car and they went on right. could something be bent ?

i grooved the OD of my poly-graphites that i put on the rear spring plates with a table saw, a saw curf wide and about 1/8" deep. i then placed a zirk fitting on the spring plate cover aligned with the groove and drilled about a 3/8" hole in the bushing to accept the zirk. i grease them once a year or so. no squeak, yet.

[Wil Ferch]

Toby:
OK...this works for the outer unit of the rear spring plate bushing...what about the inner unit, I can't think of a way to zirk fit that one, right?

If I'm wrong, please post a pic or dwg.

- Wil