Suspension bushing, the right way

[dougcl]

I'm a little confused here. Is the intention to fit the bushing so that it is tight in the bracket, but frictionless against the A-arm?

Regarding the zirc, are you confident that the hole you drilled in the bushing will stay lined up with your zirc fitting?

-Doug Clauder

[CamB]

doug - that is what I was told by someone who ought to know.

[Bo]

I did my suspension last winter, both front and rear, and the squeeking is driving me nuts (even though it IS kind of cool, and "racey" ) - this thread tells me what I got to do next winter!
BUT - what about the rear suspension? Same technique? Most of the squeeking in my car is from up front, but I also have noise coming from the rear.

[dickster]

chuck

excellent tech post.

this is something i need to do. i got original soft, worn, rubber bushes. its difficult deciding what to go for - i do not want a sqeaky ride!

i'd definitely be interested in a bushing service (would you consider shipping to uk?). but would you be able to do it on an exchange basis? i need my car (only driver) so i would want to buy the bits already preped, then send you my old bits when i'm done. obviously, you could take a deposit until i return them.

you need to put together some idea of cost.

[ChrisBennet]

Great post Chuck. I've had the street hardness bushing for years with nary a squeak but I probably got lucky. I might recommend a 4th option - rebuilt exchange. I.e. Like you do for rebuilt parts where you get the "new" one and replace it and then ship the old "core" back so your car is not out of service waiting for the rebuild.
-Chris

[jstgermaine]

Count me in as a customer for the 'Extra Value Meal Deal #3'.

Chuck as you know I'm in the process of obtaining all of the parts for my suspension upgrades. Let me know the price!!

[HawgRyder]

Excellent pics of the mod Chuck....
I had not considered Delrin for the bushing material....but now that seems very attractive.
Fortunately, the company i work for uses Delrin everyday...sooo ..I have a good supply!
I made new bushings for the shifter coupler out of Delrin...and they work great.
Also....Would pinning the bushing be correct?
Perhaps using a longer zerk fitting to go through the metal and into the bushing to stop any possibility of rotation?
Would a spiral inside be a better way to distribute grease (like a slow thread)?
Or...perhaps if concerned with outer rotation..a groove on the outside to allow grease to travel around the circumference to find the hole to the inside?
Bob

[Jdub]

Doug:

That is my uderstanding for the Poly bushes. The original rubber bushes were vulcanized to the arm and the clamp would catch the rubber well enough that the rubber bush worked by the natural give of the rubber itself.

The zirk is meant to interfere into the Poly bush, ideally into the channel you have cut for the arm-to-bush-side of things. It would seem that it is all about using a zirk that is long enough to pin the bush between the clamp and the bush proper.

Great thread. I have a set of rubber bushes and am wondering exactly how this are going to work when I go about this business. I have some concerns but HATE a squeaky suspension.

John

[dickster]

chuck

you still considering doing this bushing service??

[Gunter]

Thank you, Chuck. What size is the drill and tap for those grease fittings?

[dickster]

does anyone know if the front and rear a arm bushings are the same parts??

thanks

[sayah]

They are not. Why they are not is a total mysterey. The size difference is infinetesmal and just adds to the confusion of trying to maintain a car propertly. The arrogance of the porsche designers knows no bounds.

[Jdub]

If you have purchased "original" rubber bushes from the Jerry Woods outfit (they provide a bushing replacement service for the A arms) you will find it is a "one size fits all" item.

That said, I believe anyone replacing the bushings with these will have to vulcanize the bush to the arm, and then capture the outside of the bush by heating the clamp and laying it on the bush hot, forming the bush to the bracket so at to emulate the original technique.

I am in a quandry about going with the rubber or just putting up with the nylon bushes, which I don't like. Neatrix bushes are not an option as they decided these were too loose for the front end (the material proper is too "rubbery").

John

[dickster]

I am in a quandry about going with the rubber or just putting up with the nylon bushes, which I don't like.

i know the feeling! theres so many options here.

i feel more comfortable about customising the harder ones to fit now i've read chuck's threads etc, so i'm swaying towards that.

the weltmeister street seem to be a good compromise. the reason for the question is that i was going to order the bushes from performance products (20% sale) but could not find the rear a arm bushes listed.

(wayne, couldn't find them at pelican?)

[Argo]

I'm dealing with this as well (squeak in right front A arm). In the March 2002 issue of Pano, there is an article on 911 bushings wherein the tech editor says that factory bushings for the front are still available (part # 914.341.422.00 - superceding the 911 part # - for the bushing in the front of the A arm and part # 901.341.421.03 for the rear of the A arm). Supposedly these #'s are still good although he states that none of the later model parts catalogs list them. Anyone know anything about this? If they are really available, it would be a nice option for those of us without lathes/drill presses/grinders handy.

Argo
88 Targa

[Jdub]

Argo:

Even if we could purchase the originals it is the process of heat-bonding the rubber to the A arm that (for me anyway) would be out of my realm.

Thanks mightily for the part numbers though. I may try to score a set just to see if I can. I mean, how expensive can a Porsche bushing be (ha ha, choke choke...)?

John

[Argo]

Hmmm, I thought only the rears trailing arm bushings were vulcanized on (since mid-1968) and that the fronts were hard to get off just because of age/compression. That raises the question - does it matter if the front bushings are not "permanently" fastened/vulcanized on? Wouldn't they be held in place by the clamp/pressure, especially after they had weight on them and/or had started to "flow" or would lateral movement from braking/acceleration eventually move them out of position? The street hardness/poly/zerk fitting solution counts on them not being completely fastened in order for the grease to circulate around the shaft. And if they did need to be "vulcanized on" isn't there a glue/epoxy that could do the job? As you can probably tell, I'm still learning about this - so far I've just greased the sway bar bushings hoping that they were the source of my squeak and haven't laid a wrench on the control arms yet. It just seems that there has got to be an easier way to address what appears to be a really common problem. Hopefully someone with real world experience beyond my internet research can help out here ...

Argo
88 Targa

[KTL]

Well, I had mine redone by SmartRacing who are a good bunch of fellas from what i've seen in talking to them.

Replacing the bushes required SR to send them out to someone for installment. If it was just a matter of slapping the bushings in place and putting the brackets back on, they would have done it in-house. Wasn't cheap either.

[89911]

A couple additions: Yes you can add a zirk fitting to the rear spring plate, but only at the outer cover. Use the same drill hole through bushing and add fitting that Chuck described earlier. Also if you don't have a lathe, a more cruder but effective means to reduce the outer diameter is to fit the inner portion on a power drill and push against coarse sand paper. Make sure the bushing cools completely before determining more needs to come off. A hot bushing will add a few millimeters of circumference.

[dickster]

i don't believe the front are vulcanized on? i understood that they are just a very tight fit.