Ideas for replacing trailing arm hinge pins

[David E. Clark]

Hi. I'm replacing the steel trailing arms on my 1973 911E with aluminum arms and I'm looking for ideas for replacing the hinge pin which was not included when I bought the aluminum arms. It's part number 901 331 571 07, item number 11 in the diagram below. The old one is welded to my steel arms. If I want to use my old sway bar do i have to special order these pins and hope they come in and that they are properly threaded for the aluminum arms? Are folks removing the one's welded to the steel arms and rethreading them for the aluminum arms? I'd hate to destroy the steel arms by doing this! Is there a source for these pins outside of Porsche? What are my best options if I decide to go with an aftermarket rear sway bar? How will the aftermarket pieces attach? The car is a weekend driver which I'd like to handle better than stock but I will not be racing it. I'm just looking to make it a bit more fun to drive so I don't need a top-of-the line racing sway bar . Thanks for any help or ideas!

[Zeke]

David, there are plenty of threads in the archives about this. However, I'd like to say I don't think the balls are the best system. You have the opportunity to upgrade with a few inexpensive parts that will be more reliable (I had my SB pop off the balls).

Call Chuck M. at Elephant for the best and easiest solution. My .02, that's all.

[911st]

The Alloy arms use a bolt instead of a ball to attach the sway bar. You can just substitute a different drop link I think. Better to buy an adjustable one.

A 73E's are getting to the point where they are to valuable to make to many mods to them due to possible limiting of value and marketability.

Also, the fastest track driver I have met had a early chassis with a 2.4S spec motor and 225's on 15x7's at each corner. He was faster than every one by a big margin on the track. He ran steel arms and no rear sway bar with 22/28 torsion bars. For AutoX he ran a rear sway bar to get the back end to slide around and rotate better.

[Carrerax]

I have a pair of those "11 parts. I ordered through Auto Atlanta and they took forever to get. I bought them to put on my 911t steel arms so I can run a swaybar. I decided to just put on a set of late Sc arms instead. I will sell them if interested but not sure they will work with the alum arms though.

[911pcars]

If your al. control arms have a threaded boss, they're from a '77-on 911. Earlier al. arms use the ball attachment, but not sure how they're attached to the arm or whether these parts are still available (check the parts manual?).

That said, only the factory and one aftermarket vendor uses the control arm to mount the drop link, and that product (Charlie Bars), is NLA. AFAIK, all other aftermarket sway bars attach the drop link to the spring plate. So that's an option available to you as well.

If you want to keep the factory bar, you could also try to trade with someone for their earlier al. arms.

Sherwood

[Carrerax]

David,
You have a PM.

[David E. Clark]

OK, I have the post 1977 threaded boss aluminum arms which I've cleaned so they look almost new and pressed in new bearings and bushings - seems a shame not to use them! It looks like no one knows of a ball attachment hinge pin which I can screw into these arms so I can use my current sway bar. I guess I have three choices:

1. Purchase the pre-1978 aluminum arms with the ball attachment that I could use with my current sway bar. (I could sell or trade the threaded aluminum arms);

2. Sell the new arms to some lucky guy who won't have to do all the cleaning and pressing and keep the stock set-up and just replace all the rubber bushings; or

3. Use my new aluminum arms and get an aftermarket sway bar that attaches to the spring plate.

#2 is certainly the easiest but #3 seems to offer the most upside. #1 seems to be more trouble than it would be worth (I know, that is where I was headed in the first place)!

Anyone care to chime in with an opinion? Will installing the lighter and stiffer aluminum arms and purchasing a quality aftermarket sway bar (another $300.00-$500.00) give me a significant performance improvement over the stock setup with new bushings? Anyone have another idea for using the threaded aluminum arms? I'm not terribly concerned with altering the car since, as long as I don't damage the steel arms, I can always re-install the stock setup. Thanks.

[BK911]

I have a pair from a '74 I would trade you. THey are bare and dirty though! I am using a welt sway bar so i don't care about the ball socket.

But personally I don't think you'll notice a difference switching from steel to al.

[rw7810]

If you want t ouse your current al threaded arms why not have a ball pin fab'ed that would work ?

[Dan J]

David,
You can also install a stock sway bar from a 78-86 911. They come in several sizes (18,20,21mm) and will bolt right on. You can probably find one used pretty cheap from anyone who's upgaded their's to aftermarket. If you were here in CT I'd give you one, I've got a pile of them

[barney911rs]

If upgrading to the Alum. trailing arms, I agree with the others that said to upgrade the rear sway bar as well. If you are on a budget, the Weltmeister bar will be fine and it mounts to the spring plate insetad of the banana arm. That's what I'm using on my car.

[David E. Clark]

Originally Posted by Dan J

David,
You can also install a stock sway bar from a 78-86 911. They come in several sizes (18,20,21mm) and will bolt right on. You can probably find one used pretty cheap from anyone who's upgaded their's to aftermarket. If you were here in CT I'd give you one, I've got a pile of them

Thanks for this information Dan! This sounds ideal. Use my new aluminum arms and get a bit larger SC sway bar. Are there any modifications I'll have to make or any additional hardware I'll need to buy?

I bought my car in Connecticut years ago. Believe it or not it I looked at 14 72 and 73 911s over a three year period from TX to NY and the CT one was the only one I looked at with absolutely no rust!