924Board.org

[jpf]

I have a 77.5 car and a 78 parts car; the 77.5 is the project car, and came with no sway bars. I am trying to transplant the sway bars over from the 78. I have a couple of questions:

Front:
The 77 control arms do not have the cups to accept the sway bar ends; the 78 arms do, but they have the wrong size ball joint (17mm, vs. 15mm) and therefore don't fit in the 77.5 steering knuckles. Can I just transplant the steering knuckle from the 78 car along with its control arms? I see an un-annotated potential difference in part number in the porsche catalog, but it isn't clear what it signifies. Will the 78 knuckle just bolt right up to the strut and steering arm?

Or would anyone recommend trying to fab up a set of mounting cups for the sway bars onto the 77.5 control arms?

Rear:
The mounting brackets for the sway bar will be welded to the torsion carrier. I'm wondering about the long eccentric adjustment bolts: should I just transplant the bolts over from the 78, or is there any advantage (and is it possible) to transplant the whole trailing arm?

Thanks for any advice, this is my first significant suspension work.
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924 Beginner, messing with suspension.

[fiat22turbo]

I'd swap the control arms and uprights.

The rear carrier can be swapped and isn't too hard.

You could put stiffer torsion bars in as well while your at it.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[the_mad_electrician]

There's a how to in the how to section about this, I think its called "how to install a rear sway bar on car without"
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81 924 N/A

2004 Ranger "Edge"

2005 Mazda 6

[Rasta Monsta]

Yep, take everything off the 78 (control arms, sway bar, strut housings, steering knuckles, entire rear suspension as a unit) and slap it on the project car.

Great opportunity to rebush the suspension, replace ball joints, strut inserts, wheel bearings, so a CV service, refresh shift bushings.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[stpangia]

is it a problem that the '78 rear suspension has rubber mounts and additional mount points while the '77 does not?

there are couple of images at the link below that point out the additional mounts on the '78 outboard of the carrier tube and at the top of the wheel well:

http://porschenator.tumblr.com/post/2061368401/suspension-assessment-11-27-10-under-the-rear

would the swap require fabrication and welding to accomodate these mounts on the '77? can't just connect them to nothing, right?

[fiat22turbo]

Torsion tube looks to be the same.

Use the 77 mounting parts on the 78 tube.

Or add the later-style mounts to the 77 chassis.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[fiat22turbo]

This might help:

http://s148.photobucket.com/albums/s10/fiat22turbo/Porsche924/Histerical/Articles/Handling/
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[Andrew NZ]

In mine, I've retained the original torsion tube and welded on swaybar mounts. At first I kept the stock arms and plates and simply machined the eccentric off the drop link mount bolt so it would fit the 77.

I've since replaced the arms and plates with later model ones, wich works if you gently sand down the bushes to allow for the thicker double plate on the later spring plates.
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Andrew
1977 RX924 race car
12a bridgeport supercharged
www.race4-dcup.co.nz

[jpf]

Thanks for the tips and resources. The original plan was just to reindex the bars without dropping the carriers (the 77.5 has the access holes in the side panels) and keep things simple. We would weld on new sway bar brackets there, that we have almost finished.

We'll look more closely at the torsion tubes — maybe we can swap just the tubes and keep each car's normal mounting hardware, as fiat22turbo suggests. If we can do that and swap the trailing arms, having the ride height adjustment bolt would be nice.

At the front, I'm interested in doing the steering knuckle swap. I guess I'll just look out for rod end issues per this thread: http://www.924board.org/viewtopic.php?t=22777&postdays=0&postorder=asc&start=0

Thanks again, I'll let you know how it goes...
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924 Beginner, messing with suspension.

[jpf]

Well, the front is in good shape. We ended up swapping out the ball joints and keeping the knuckles where they were. New inserts fitted and the ARB is good to go.

At the rear, we had trouble: with the end cover off, the spring plate will not slide out on the torsion bar to pop down out of its preloaded state. We ended up trying it with and without a jack pushing up on the end of the spring plate, starting off prying with a big screwdriver, eventually ending up trying to pry it off with a five foot pole with a wedge end. We bent the spring plate a little (!) but never got it to pop off. There was lots of rust and some totalled threads in the suspension parts, it looks like it's had a hard life.
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924 Beginner, messing with suspension.