Torsion Bar Problem, or maybe something else

[squelch]

I drove my car to work today (about 23 miles) and everything was fine. I came out of work a few hours later, started it up, and drove forward 2 ft, when I heard a loud pop, and my right rear, dropped (see picture).

Any ideas. I am thinking it is a torsion bar problem, but don't know exactly what. Do these things break, or come lose in some way? It is amazing it happened all of a sudden, after being parked for a few hours, instead of on the highway at 80 mph.

Any comments or suggestions are appreciated.

Chuck

[Oh Haha]

Yup, most likely torsion bar is broken. Did you check out the suspension pieces yet?

Did you have it towed home, I hope?

[tonythetarga]

Tough luck. Torsion bars can break. Look to see if the shock mount on the lower arm is in place. If everything else looks normal then it probably is the bar.

[squelch]

Thanks gents. I did get it towed home and I pulled the wheels off and inspected everything. It all looks fine. I am now in the middle of reading all of the other torsion bar posts.

Since I have to replace them, the obvious questions are:

1. What should I replace them with if I want a somewhat sporty suspension for a mostly road car with an occasional DE here and there?

2. Should I also replace the fronts?

3. Anything else I should do while I have it all apart?

4. I've looked at the Bentley Manual and the 101 manual, and it looks like I should be able to do this in my garage with normal tools and a floor jack. Anything special I need, or need to know?

Thanks,
Chuck

[jtfreels]

If you need a hand with this just let me know. Not that I've ever replaced a torsion bar.

Jay

[squelch]

I have bought a pair of torsion bars from another Pelican and am ordering some new spring plate bushings. Is there anything else I need for this project before I complete my order with Pelican?

Thanks,
Chuck

Jay, Thanks for the offer, I sent you a PM.

[Rot 911]

Did you buy new or used? If used make sure they don't have rust or pits in them. All you need is the bushings. Did you get Neatrix? There is a tech article on how to remove the old bushings from the spring plate. For me and many others using torch on the inside of the spring plate works best. Hopefully your torsion bar broke close to the end by the spring plate so it will be easy to get out.

[tonythetarga]

Hi Chuck,
You will need a carpenters angle gauge which you can get a Home Depot for about 10 bucks. Once you get the car on jack stands (all 4 wheels) put the gauge on the sill plate of the door to make sure the car is level. Once it is, then check the spring plate angle once you release the shocks and unbolt the eccentric bolts.
You can use this spring plate angle calculator : http://vintagebus.com/cgi-bin/spring.cgi
to re-establish your ride height with the new bars in place.
You will need a 12mm allen wrench (hard to find but I found one at Sears) for the eccentric bolts on the spring plate.
Tony
ps, thanks for your patience re: all the pm's

[jtfreels]

Chuck,

I've replied via pm. This looks like it will be fun

Jay

[squelch]

Well, here is the damaged part. I have the car apart now, and am going to start putting it back together today.

A couple of questions for the gurus out there:

1. I have read all of the debates about whether to put grease on the new spring plate bushings. I am going to go ahead and do that, but I need a grease that is bushing friendly. I have some Mobile 1 Synthetic grease. Is this bushing safe? If not, what should I use?

2. After much reading about how to re-install the torsion bars, I have a good idea about how to set ride height. However, when I called my local mech to ask about the cost of an alignment, he said that I also need to put the car on scales. I haven't seen any other info about that being a requirement and I don't totally understand the need. Any info on this would be appreciated. An alignment runs about $250, but if he puts it on scales it runs about $500.

Thanks,
Chuck

Pics:

[2.7RACER]

Hi Chuck,
Replacing one or both of your torsion bars will require the car to be corner balanced.
Essentially the replaced bar can raise or lower that rear corner slightly, changing the weight placed upon that wheel and the weight placed on the opposite front wheel.
In your case the driver side front wheel.
This unbalanced suspension will affect your handling, braking and tire wear. You will not like it.
There are a couple of procedures you can do at home to get the corner balance reasonably close.
However scales measuring each corner in the hands of professionals are the best to get your car correct.

[Superman]

I had mine corner-balanced and aligned for just under $300. Prices vary. Widely, apparently.

In my mind, the grease controversy is settled. Silicon grease. Dow Corning 111 or 112.

[ljowdy]

I know that VW torsion bars have different number of splines on the inner and the outer so fine adjustments can be made. The inners splines are 9 degrees apart and the outer splines are 8.1 degrees apart.

Are Porsche torsion bars fabricated in a similar fashion???

[2.7RACER]

If the alignment shop can corner balance your car without needing to pull and reindex the rear bars the cost to corner balance will be fairly low.
If they need to reindex the rear bar or bars, the time to do the job and the cost go up.
The key here is to get the rear adjustment as close as possible before it goes to the shop.
That is unless you value your labor higher than the shop charges.

[boyt911sc]

Originally Posted by ljowdy

I know that VW torsion bars have different number of splines on the inner and the outer so fine adjustments can be made. The inners splines are 9 degrees apart and the outer splines are 8.1 degrees apart.

Are Porsche torsion bars fabricated in a similar fashion???

YES. The rear TB's for 911 cars (pre-G50) have 40/44 (inner/outer) splines. Inner 40-splines = 9°; outer 44-splines = 8.18°. Similar angles as VW but differ in diameter and length.

TD

[Gunter]

squelch:
This is the time to decide about ride-height and Camber/Toe settings BEFORE you go for alignment/cornerbalance.
Most people don't want the factory settings.
Fender lip to ground 25" front and 24.5" rear is popular.
Do you have the bump steer spacers under the front rack?
Camber front 1deg negative and 1.5deg negative rear with Toe-in total 1/8" front and 0 rear is good for mildly aggressive street driving.

[squelch]

Thanks for the input gents.

Gunter,
I appreciate those numbers. I have purchased a bumpstear kit but haven't installed it yet. I imagine I will then need to re-adjust everything once I do.

[Gunter]

On a 4-wheel alignment, everything has to be re-done anyway.
You'll like the bump-steer kit. Center the steering wheel and tie it down. Loosen the U-joint on the steering column in the smugglers box so you can push the rack up and install the spacers.
It helps if you open the bolts/nuts on the rear spring plates one by one, grease with anti-seize and tighten again.
This will help the mechanic who is doing the alignment/cornerbalance.
Check all bushings and replace if necessary before you go for the alignment.

[squelch]

I got the bumpsteer kit installed with no problem, and set the front end ride height at 25 in. This was a bit of a challenge, until I discovered that the right front tire is 10mm taller then the left. I don't know why. They are the same brand and size and have similar wear. I ended up letting some air out of the taller tire to get the heights the same, so that I could ensure the torsion bars were set accurately.

I also got the rear torsion bars installed. I set all of the cam bolts close to a neutral position and set the radius arm angle at 30 degrees, per the calculator I found here.
This gave me 25.5 inches on the left rear and 24 7/8 on the right. Not bad for a first shot, but I am going to take it apart again tomorrow and try to get a bit closer to 24.5. then I will fine tune it with the cam bolt.

So, once I get the ride height, what would you all recommend I do about getting the alignment and balance as close as possible before taking it to my mech for an alignment. Anyone have a favorite article or description on a home alignment?

Thanks for all the help. This has been a good project. I am learning a lot.

Chuck

[tonythetarga]

Great work Chuck!
Regarding the ride heights you gave - were they taken after you gave the car a drive to have the suspension settle back in or taken after putting the car back on the ground? Hopefully you have taken it for a short shakedown drive.
I'm afraid I can't offer help on the home alignment or corner balance, I had mine done at the shop for a price I could not refuse.