Rear Trailing Arm Angle

[Ozzie]

I've ordered the 28's. Sway-A-Way. Does anybody know the initial angle to set the trailing arms?

[fullnoise56]

I've got 28mm bars on my Oval. The suspension is set as low as possible for handling. I have about 10mm chopped off the bump stops. This leaves about an inch of travel between the bump stop and the actual stop. The car soaks up bumps and doesn't feel like it hits the stops.

From memory I set mine about 3 degrees below horizontal (With the car horizontal measured with a spirit level along the bottom of the door jam). My car weighs 750 kilos. The car may have sagged a little in the past few years so I might consider resetting them. Perhaps you should try 4 degrees.

CYA CT

[Southernbug]

The spring plates should be at approximately 20 degree angle to the chassis in the unloaded position. This varies from model to model. Less of an agle on lighter cars (15 deg.) to higher angles on the lheavier later model versions (~21 deg). If you are using stiffer torsion bars I would recommend you start in the 15 to 18 degree range. Be sure the spring plate angle is consistent on both sides. A 5 dollar magnetic base angle finder from Harbor Freight Tools is great for this job. Both Haynes and Bentlel manuals have the angles listed for rear torsion bar preload by model year. There is also good info on the link below:

http://www.vw-resource.com/rearaxle.html

Good luck!
Shane

[Ozzie]

Shane,
What size is the hex bolt that mounts the diagonal arm to the chassis?
Do the axles need to be pulled to change out the torsions? How bad is that?

[Southernbug]

I sent you a message. Drop me an email or give me a call. I just did that procedure so I got tons of info/tips.

Take care,
Shane

[Bruce2]

Shane,
What size is the hex bolt that mounts the diagonal arm to the chassis?
Do the axles need to be pulled to change out the torsions?

17mm

You do not have to remove the axles like the Bentley manual says you do. They are wrong. You do have to remove the shock, and the rubber snubber so you can lift the TA high enough for the spring plate to be removed.

[sideshow]

The spring plates should be at approximately 20 degree angle to the chassis in the unloaded position.

Yes, but 28mm are way stiffer. Eye ball it, drive 500 miles, correct.

[Ozzie]

Shane,
What size is the hex bolt that mounts the diagonal arm to the chassis?
Do the axles need to be pulled to change out the torsions?

17mm

You do not have to remove the axles like the Bentley manual says you do. They are wrong. You do have to remove the shock, and the rubber snubber so you can lift the TA high enough for the spring plate to be removed.

17mm, same size as the Allen Key for the trans. Got one! I'll just put a pipe on it.

Can you get the spring plate off the tortion while it's still bolted to the diagonal arm (or bearing carrier or whatits called)? The other end of the spring plate. To keep from messing up alignment.

[Southernbug]

Hey Oz,

You do need to unbolt the spring plate from the diagonal arm. Just scribe the location of the bolts in there slots before you take it apart and it will help you get close when you get it back together.

Shane

[Ozzie]

I hate rain.

[Ozzie]

OK guys. I'm to the point where I need to get the spring plate off the perch. I've got the nifty tool from AirCooled that looks like an all-thread jack. I've got tension on the spring plate to raise it enough to get daylight between the plate & the perch. OK. Now, do I force out the spring plate so it flexes out from the perch, or do I try to get the spring plate to move out a bit at the tortion bar end? I've tried both, but without a lot of gusto. Not knowing what I'm doing & don't want to break anything.
Thanks for the help.
Oz

[EDIT] Nevermind.

[Southernbug]

Hey Ozzie,

Sorry I missed your call. Here is how I got the spring plate off the perch.

STEP 1: SAFETY FIRST!! I attached a safety chain from the top shock mount to a spring plate mounting hole (AXLE end of the plate). I used the chain to keep the spring plate from flying off in crazy directions.

STEP 2: I used a crow bar behind the spring plate and every so gently pried it off the perch. The torsion bar will sometimes come out with the spring plate.

STEP 3: If the spring plate is under spring tension use the threaded spring plate tool to lower it down.

Hope this helps. Give me a call if you need any more help.

Good luck!
Shane

[helowrench]

I wasn't quite as gentle.
I just used a 2lb hammer.

BTW I measured the angle after it was off the perch and set them back to that angle once the new bars were in....................
now the ghia sits about an inch higher in the rear than it should.
I now need to go back into it and adjust again, but I am waiting until I get some 924 trailing arm assemblies first (2" worth of hieght adjustment availible via the eccentric bolt)
Mine did not settle any noticeable amount in the 1 1/2 years since I have done it.
I left the axle/drum etc in place when I did mine.


Rob

[Ozzie]

Rob, what size (diameter) bars did you go to?
What shocks and sway bar are you running & howz the ride?

[helowrench]

22mm (stock from a 78 Porsche 924NA). on the rear with no swaybar and some unknown gas shocks.
KYB gas-adjust on the front with the stock swaybar.

Love the ride,handles great, but want more sway bar on it.

I plan to go back to the KYB GR2 shocks on the front and go up to the KYB gas adjust in the rear also.

Rob