Another A-Arm Bushing Question

[jjeffries]

Greetings All from New England,

I'm planning for a suspension refresh on my 190K mile 82 SC this coming winter, and as such have been reading and asking questions on some excellent threads,,such as Craig_D' s superbly documented suspension overhaul story, and CGARR's elegant modification of stock adjustable spring-plates to add easier adjustability.

I'm looking to keep my car street-friendly, so rubber parts are what I really want but you'll all know there are many other choices, and some concerns with today's rubber parts. How so? On one hand, it's been said here that today's rubber compounds are better than ever, such that pieces like Elephant's Sport Rubber compound are BETTER (or at least as good?) as what Porsche used when the car was new. But then I have been told (the opposite), that today's rubber compounds are necessarily compromised by the environmental laws controlling the ingredients used and, like lacquer paint and that ferocious carb cleaner we all miss, what was permitted 30+ years ago is now missing from the recipe to the point that today's rubber bushings are less durable and won't last more than a couple of years. That's why I asked in Craig's thread how his and other's bushings are holding up; everyone seems to be saying "just fine". Granted today our 911's are likely being driven less miles.

The choices among rubber bushings seems to go from URO, the accounts of which are very poor, to equivalents from Elephant, Rennline and Rebel. I already have Elephant "sport" rubber in the trailing arms of my car, done "while I was in there" with the motor and 915 out when I first got the car. I'd go for Elephant's A-arm bushings in a heartbeat (have watched all the videos, etc) but at $80/per and thus $320 for a set I just ask myself "Really?". I will pay for good parts for my car but that price in particular feels like admitting I'm an idiot (something with which I require no extra help, thank you very much).

That $320 would come close to buying Rebel's cartridge/alloy trick set. But that's not really the way I want to set up my car, neither would I want polybronze or poly-anything.

The point of this inquiry? In a thread started in 2010 when Rebel released their cartridge a-arm bushing set, the always interesting Chris Seven from Fenn Lane Motorsports in the UK asked why we aren't using the original Porsche part? Because Porsche no longer makes them, everyone said. But Chris provided a P/N, which I checked here on PP again today and it shows as in stock: 914 341 422 01 @ $22 each. Pelican also states "this will fit your 1982 911 SC".

Hmmm. Has anyone used these OEM Porsche bushings to rehab their A-Arms? There are numerous parts in a 911 with a 914 prefix (shift bushings come to mind), so we're not missing these just because we think they're 914 applications, are we? The pricing is closer to URO than Elephant. Are the Porsche OEM bushings and everyone else's all from the same rumored supplier? Is the rubber used in today's parts worse/better/same as what OEMs used in the golden days of manufacturing? Any/all feedback welcomed. Best regards to everyone, John.

[RSTarga]

I installed the elephant sport rubber bushings several years ago and they are holding up quite well. We evaluated them against URO at the time and URO was quite a bit looser fit.
Chris is quite knowledgeable though and you might order a set of those to compare with Elephant. Probably worth it it to compare.

[HaroldMHedge]

I put in Elephant Racing rubber bushings in my SC. They worked great.

While researching a suspension rebuild for my Carrera I came across this thread where chris_seven has used the 914 busing numerous times, Front Control Arm Bushings - Which ones?.

Originally Posted by chris_seven

I don't like PU Bushes on Front Control Arms and having to re-grease is a pain.

Once the grease washes out the friction of the PU is way too high and will affect static ride height.

The URO 'Slip-In' bushes are just wrong.

When you fit the bush there is no radial compression which has a significant impact on the static and dynamic modulus of the material which will affect stiffness and hence alignment of the arm.

They are easy to fit but don't align the front very well.

The description offered by ER about the need to fit the bush with significant force is absolutely correct.

The ER Bush does, however have a slightly larger ID than the Original part used by Porsche and hence has just slightly less compression than the stock part.

Bushes are available from Porsche with Part Number 914.341.422.00 at around $15-$16 each

They are listed as a Rubber Stop and shown as the front bush for the 1965 Control Arm but this is also an error.

The 1965 Car used a bush that was similar but longer by around 10mm longer (The replacement bush does work but isn't 100% correct)

The current bush is 35mm long and fits into the outer housing and then presses into place over the control arm.

As it presses into place it stretches to around 50-55mm long and fills the housing.

They are a PITA to fit but we have made tooling.

We have used them for 7 years now with good success and have fitted more than 50 sets.

I have never used the ER Parts but would assume that they are very good.

[jjeffries]

I'll just really be surprised if there has in fact been a Genuine Porsche solution for this all along, and at 4 x $22 = $88, to boot. Or, 4 x Genuine Parts bushings for the price of one Elephant bushing plus $8. Maybe the Elephant bushings are better than Genuine Porsche items? If so, how? Are the Genuine Porsche bushings any good? John

[Edoyle]

I bought Rennline bushings. Factory bushings are designed to deflect with no pivoting movement on the arm or in the brackets. The Rennline units, as I found out, are meant to slide within the A arm bracket and on the arms as they are much too stiff to deflect. I greased them well but they have lots of resistance as the stamped surface of an a-arm bracket is far from a smooth bearing surface. I have yet to install everything on my car but I'm thinking that the minute these bushings start making noise they are off the car and I will install factory bushings that do deflect.

[Mark Salvetti]

I always thought it was strange that the ER rear spring plate rubber bushings are only $100 for the full kit, but the front A-arm rubber bushings are $225.

Oh, by the way John, the early cars are $320 for a set of four. Your car they are "only" $225. And if you are a PCA member and haven't used your Pelican 10% discount yet, you can get them down to almost $200.

Mark

[jjeffries]

Thanks for the feedback guys, incl that correction on the pricing Mark; I don't want to be spreading any misinformation. I still need to join PCA. John

[sugarwood]

I've also not summoned up the courage (or recently motivation) to do a suspension refresh.
I planned on trying the more basic front first.
Stock is for me, so I will go with this OEM Porsche bushing.
914 341 422 01

[jjeffries]

Can any of the experts advise whether the Genuine Porsche bushings should be glued and set-up with an angle-finder, as with Elephant’s product? Thank, John

[Tbone1209]

I just did both front and rear and went with Rebel. I like the fronts because the kit includes all new anodized billet mounts for not much more. The car is transformed. Very responsive and more compliant because all the stiction from the rubber bushings has been removed.

[Craig_D]

I called Chuck Moreland at Elephant Racing and discussed my build with him, including new factory rubber bushings versus poly bushings, versus poly-bronze and other similar (ie Rebel) products.

I know that he wants to sell his products, but he was very very knowledgeable about the competing products, and after these conversations I decided to go with his ER Sport rubber. I did it because his explanations mades sense, and because I believed that his products would last longer and perform better for MY SETUP (ie not a track car, but a competent, balanced and improved street car). I figured that a. I didn't want to redo the work in a year or two, and b. that if it didn't hold up, I knew how to replace them.

Give Chuck a call and see if that helps your decision one way or the other. As I've said before, I'm extremely happy with the way my car handles, stops and transitions with the ER rubber (and PolyBronze springplate bushings), and I do DRIVE my car the way it's meant to be driven. At speed over washboard corners, it handles like it's on rails and super smoothly.

Cheers,

- Craig_D

[sugarwood]

Originally Posted by Craig_D

MY SETUP (ie not a track car, but a competent, balanced and improved street car). I figured that a. I didn't want to redo the work in a year or two, and b. that if it didn't hold up, I knew how to replace them.

Why did you think factory rubber would need to be replaced in a year?
On many cars, it has lasted many years from the factory.

[DRACO A5OG]

Something of note, I upgraded to Rebel Bushings and new thicker T-bars 6-7 years ago, loved them but recently developed an annoying Squeek and the T-bars were rubbing inside the tubes. WTD

I took the front apart to discover the squeek was coming from the front of the arm pivot at the bushing where it was rubbing against the chassis' two bolt mount bracket and strangely the t-bars rubbing inside the tube at the cross member end. If you see signs of wear or exposed metal where the front mounts are rubbing you have to add some shims/spacers ( I used Rebels conical spacers ) or the new rubber type bushings will soon compress and arm will rub.

I also added some home made 1.5" Delrin shims/sleeves inside the tube to keep the T-bars centered at the cross member, to keep it from rubbing on the cross member. I had Velios rebuild the cross member where the caps wore a groove in it and I installed new Dansk Arms with factory bonded OEM style bushings.

[jjeffries]

Appreciate everyone's thoughtful repsonses. John

[manbridge 74]

Originally Posted by sugarwood

Why did you think factory rubber would need to be replaced in a year?
On many cars, it has lasted many years from the factory.

The rubber does last but can cold flow causing bushing to go out of round in around 10 years. Even from sitting due to weight of the vehicle.

I went with sport hardness bushing from elephant, (you can feel difference over small bumps)and will check in in eight years!

[KTL]

Experienced the same as DRACO Jim describes. When you put the front suspension under heavy loads like canyon driving or track driving, the original rubber will compress and your fatter t-bars can rub on the crossmember. In my case, I had 22mm torsion bars and the bushings are new original Porsche bushings installed on my A-arms by Smart Racing back in the days before Elephant and Rebel had their offerings. I think it was 2001 and at the time I figured it was the best way to go since I wasn't going to install "plastic" bushings.

I built up my crossmember with some steel pieces that I epoxied in place with JB Weld

Bushings shot at 110k on 85 Carrera

[jjeffries]

Maybe there is some psychological benefit to being cash-poor: you get to obsess about how you'll spend the shekels once you have them. When I got married in 1990 and took my lovely bride to meet family in England, my Mum's best friend gave us some advice for newlyweds: "It's better to want something than to have it." Then I must be in good shape because I really want SSI's, sport muffler and all the do-dads to overhaul my suspension!

I just did another search on PolyBronze then re-read the installation directions on Chuck's site. Nice stuff.

I will have to look for the wear shown in Kevin and Draco's photos when I eventually get to this project.

I do find it interesting that most of the popular wisdom here (not saying that facetiously) is that there's no factory replacement parts for the front a-arm bushings when it appears there is. I don't know when the part number (courtesy of Chris_Seven) became available but I figured there'd have been some folks who by now had tried them and written about it.

Either way, it's all good. I/we are fortunate to have this distraction. Cheers, John