Polyurethane A-arm bushings - are they really that bad?

[CarreraS2]

Need to replace some worn/squeaking A arm bushings.

Doesn't seem to be a lot of options. Elephant seems good, but is more than I think I want to spend at this time on this particular car.

Did a search, there seems to be a lot of different opinions on the only other alternative, polyurethane/polygraphite bushings.

Do you really need a lathe to install them properly?
Are they prone to squeaking?
Do they make the ride a lot rougher?

Really wish there was some kind of an intermediate alternative between the plastic bushings and Elephant!

[mede8er]

Mine are squeaky..........

[tom1394racing]

The squeaking with poly bushings can be avoided by installing zerk fittings and keeping them properly lubricated.

The ride is very firm however. I had them on my 912 years ago and it was like driving a roller skate.

The Elephant Poly-Bronze bushings provide a much more tolerable ride IMHO.

[MotoSook]

You don't absolutely need a lathe, but it is the preferred method for poly-g installation/fitment...for anal retentive types like me

I recently helped Ed in Cali (Edward993) with some pointers for an install w/o a lathe...

[juanbenae]

i did not use a lathe, i used sand paper and a buddy's drill press with a drum sander for the inner surface. i did install the zirks and i went a bit further. i figured where the zirk would be lined up on the outer bushing surface and used my table saw to put a groove around the entire outside of the thing a blade width wide. this allows me to pump grease into the zirk, and in theory it will travel in the recessed cut and travel around the thing. no squeaks yet, mine is not a daily driver so your results may vary. a squeak on the inner surface and spring plate would be out of the grease zone with my method.

[CarreraS2]

Sounds like they all around suck.

Looks like I'll have to spring for Elephants.

[89911]

No problem with mine, 5 + years and most of them track miles.

[PorscheGuy79]

I have put probably 2k miles on mine without an issue, but I know thats not a whole lot. Souk did the install and did excellent work on them(he used a lathe though so no help for those who dont).

I cant tell if it rides like a rollerskate because the 23/30s keep gettin in the way.

[Walko]

I had poly bushings in my 75 which had a 3.6 and a full cage I used the car for eight years as my daily driver approx 50 miles a day as well as using the car for Porsche cup in Australia. It didn't squeak except for when i would degrease under the car before a race meeting. and then it would squeak for approx one or two days. I didn't use a lathe or install grease nipples.

My two cents

Michael

[juanbenae]

Originally posted by SoCal911SC
Sounds like they all around suck.

Looks like I'll have to spring for Elephants.

well pony up then and leave us alone.....

[MotoSook]

There are flaws in all the bushing designs...all.

[pwd72s]

Originally posted by Souk
There are flaws in all the bushing designs...all.

I agree with this. My car now runs poly on the front A arms. But I did the job by checkbook. Had the suspension completely taken apart and redone at ROTHSPORT. New shocks, turbo tie rods, other goodies. Anyway, ZERO squeaks. I didn't ask Jeff what magic was used to prevent them, but he does have a basic machine shop on site ... When I expressed a squeak worry, I was told they wouldn't squeak, and if they EVER did to bring the car back.

[CarreraS2]

Originally posted by Souk
There are flaws in all the bushing designs...all.

Please explain!

Given the big price difference, maybe I'll give the polys a try.

How can you tell what needs to be ground down on the polys, and how much? E.g., when you try to fit the bushing onto the A-arm, it won't go on, so the ID needs to be ground out some until it will fit on the A-arm? Then when you try to put the caps over them, they won't go on, so the OD needs to be ground down some?

You can't reasonably do that grinding with a Dremel, sandpaper, or something more pedestrian than a lathe?

I suppose once I can visualize what machining operations need to be done, I can take the arms and bushings to a machine shop.

[88 Club Sport]

Brian,

Are you sure your bushings are worn after only 27k or so? Sure the rubber may have hardened but for a daily driven car, I would have thought them to be ok.

I did poly's in front and after 2k or so the did squeak but I als added zerk's so that I can give htem a

[DByers]

I went with poly bushings in my 71 when redoing my rear suspension a couple of years ago. I have had zero squeeks. I also did not need a lathe or did any sanding to get them to fit properly. Being on a budget I opted for the poly and for some reason if I didnt like them, then I would pony up some $$ and look at other options. Many people recommend and use the Elephant Racing product, and they all seem extremely happy with their choice. I dont think you would be wrong in using the ER product. It becomes a matter of choice and $$.

Your choice, your $$, my .02

[88 Club Sport]

Ok... sorry about that, fast fingers (and no spell check).

Also a brain fart.....you are talking about the 914...right, not the 911...duh!

As I was saying, I added zerks so I could add grease and that seems to have solved my sqeaking problems. In fact when I did the 29 rear torsions, I replaced the bushings w/Neatrix. I am now going to 31's and will be going with Poly's w/zerks due to the cost of Polybronze.

As for fitment, know going in that you will have to spend some time on them. I used a broom handle and sand paper on the ID and with time, the fitment was great.

In F class PCA out here, most of the fast guys have Poly's.

[MotoSook]

Know that the polygraphite bushings will deform (yes, a bit) to fit the shape of the chassis, front cross member and carrier (front and rear). The A-arms and springplates are more round than the other parts that contact them.

The problem is that the bushings can be too thick (I.D. minus O.D.). It causes the bushings to "grab" the a-arms and spring plate with more force than you need when everything is in place, and sometimes enough to grab (stiction) and release leading to squeaks and too much stress on the parts involved.

There are ways to reduce/prevent stiction and prevent the squeaks. You can put a groove on the ID of the bushings to relieve some of the stiction, you can grease the bushings (zerks appropriately installed), or you can take away some of the material to reduce the drag/stiction...of course you can do all of this in combination!

Unfortunately, there is not enough uniformity in the parts that one can just machining the bushings so that it works on any of our cars. The tolerance of the parts is not ideal, and they were intended for rubber bushings which deform and take up the slop better than the plastic bushings.

I've logged a number of the dimensions on a few cars, and I suppose I could machine bushings to get them close. But it's hardly worth it since a careful tech or DIY installer could fit them with a belt sander and careful hands.

Mike and I are working on a solution that may allow for an easier installation, but it's not a priority as it will cost more than just the polygraphite bushings with a very small margin.

The polygraphite bushings are simply the best bang for the buck, and when installed properly will perform well for a long time without squeaking or other problems.

[MotoSook]

Originally posted by DByers
I went with poly bushings in my 71 when redoing my rear suspension a couple of years ago. I have had zero squeeks. I also did not need a lathe or did any sanding to get them to fit properly. Being on a budget I opted for the poly and for some reason if I didnt like them, then I would pony up some $$ and look at other options. Many people recommend and use the Elephant Racing product, and they all seem extremely happy with their choice. I dont think you would be wrong in using the ER product. It becomes a matter of choice and $$.

Your choice, your $$, my .02

Yep, I've installed rear bushings that didn't need machining. Tolerance! Not perfect or close to perfect in all case with our finely built German cars

If you perform a search, there has been discussion on the problems that can occur with all the available solutions (upgrades).

[88 Club Sport]

Brian,

Below are a few pics of my polly/zerk install.

[CarreraS2]

Craig, thanks for the pics. I wasn't quite sure how the Zerk worked in this application, but that helps.

Although wouldn't a groove in the other direction be better?

What a PITA this is!

Also, did you feel a difference in the ride? As you know 914s (errrr, 911's shhhh!) ride hard enough as it is.