Rear Banana/Trailing A-arms

Whatever you call them, I have the old-style steel ones on the back of my 911, and (since one is bent slightly) I've considered upgrading to the aluminum ones. Now, I know the aluminum ones need to be modified slightly to work with an early 911, but that they're lighter, and the bearings they use are larger.

Are Carrera trailing A-arms the same as the aluminum upgrades? I've found a set that I could buy, but I want to make sure they're the right kind.

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Jack Olsen
1973 911 T (3.6) sunroof coupe

Hi Jack,

All the aluminum arms from 74-89 are the same(except turbo) the only differance is the sway bar mount.the 74-77 use the same style you have on your car now. the 78 and on uses a slightly differant arrangment and gives you more options with attaching aftermarket rear swaybars. the later ones seem to be the preferred ones so the ones you have should be fine.

One word of caution though. If you can,get them checked to make sure they are not bent. A friend of mine replaced his steel ones(removed engine and tranny)and installed them only to discover they were slightly bent. He now has to pay to have the engine/tranny removed to replace.

Also several articles say you can get them out without removing the tranny/engine. Has anyone done this? I have been told by two different people who tried it that you cant do it. I've decided to wait till the tranny needs to be done.

I was bombarded by questions as to if alum.would work on the older non alum. All I could say is yes, but it's nice to know now that the only difference is the sway attachment. The older alum.arms have those round knobs
for the sway link to pop in (real Bi@*$), and
78+ have a bolt.

I was only able to change the banana arm bushings on my 72 by dropping the engine, which was a blast. I have been told that if the bolts are put in the right way you can do it without taking the engine out. This was from 2 good wrenches in out local PCA, but they have SCs. I tried to put them in the other way but this doesn't look like it will work either. How can you check to see if an arm is straight?

Hey Jack,
The trailing arm upgrade sounds like a good idea. I had a '73 and I R&R'ed my steel arm after I bent it at Bridgehampton Turn 4. The drivetrain remained in the car if that's any help.

By the way, you are definately on the slippery slope to making your car a trailered track-only car. Next you'll strip out the interior, install a cage, fuel cell... I've seen it many times. After that you're "starting from scratch" with a new project to go Club Racing. Enjoy and keep us informed.

Jack,
What mods have to be done to put the aluminum bananas in an early car, out of curiosity? Since I've got my car completely apart and am doing lots of other suspension goodies going in, it'd be a shame not to upgrade. I think I've found a pair, too. But I thought it was pretty much a bolt-up swap. I do have upgraded (SC) brakes to bolt on, poly bearings, adjustable spring plates, weltmeister sway, which should bolt up. How about my stock '72 halfshafts?

-d

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Dave
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http://members.nbci.com/dtwinters/garage/

I too have a 1973 911T, with the bent rear control arms. I have purchased a set of 1974 911S (Aluminum) arms and am gathering parts to swap them out (bushings, bearings, CV parts, Porsche manuals...) What modification needs to be performed to the arms?

For the '74-to'73 swap, no changes at all ... the CV-joints and axles are identical!

You would be far ahead, though, to make sure the '74 arms have the round pins for attaching factory-style anti-roll bars!
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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 12-17-2000).]

Excellence had a great, detailed article covering this a few years back-I'll go through all my back issues and let ya'll know which issue it was, and all the things to watch out for during the swap-I seem to remember the author had shock absorber/heat exchanger interference, and also had to mill away about an inch of the arm at the threaded boss for the bolt.

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Clay Mcguill www.geocities.com/the912guy

Clay, that mod. was only necessary for the 71 and earlier as they have different shocks and different shock angles than the 72 and later models. As for the engine and trans removal, it isn't necessary on 73 models because that was the first year they made indentions in the torsion bar tube and faced the bolts with the heads outwards. 72 and earlier require engine/trans removal. Make sure you get the hubs with the bananas because the aluminum ones used wider rear bearings and correspondingly different axle flange hubs. The stub axles are the same.