Speaking of torsion bars!
I just finished yesterday ajusting the rear ride height on my '81. It was not a very easy task, but with some patience and tools I think anybody can do it.
****************Disclaimer****************
First of all (Well, I added this afterwards :wink: ) I'm just sharing my experience here. You by yourself must be very sure of what you're attempting to do and be aware that you're dealing with components that are WAY stronger than any human you can think of. They can cause VERY SERIOUS INJURIES OR EVEN DEATH.
Don't forget to wear your safety equipment.
Make sure your common sense is working fine!
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There may be better/easier ways to do this, but here's how it worked for me.
I soaked the bar gears in WD40 (both ends of each one) since sunday and re-applied daily until yesterday when I finally decided (and had the chance) to do the job.
First thing to do is establish the desired ride height. Then measure the current one. The difference between the two you write down. (If you're just changing the bars, the difference would be zero :wink: )
Then you lift the rear of the car and make sure nothing is tensioning the suspension. If you don't have proper equipment for lifting and securing the car correctly, don't even try this.
In other words, the torsion bars are completely relaxed.
It might not be necessary, but I preferred to remove the shocks too.
Then you go and measure again. Find a spot, where you are sure the geometry of both sides of the car is equal. This is of course not an exact measurement, since the arm is moving in a circle, but it is accurate enough for the purpose. Write this measurement down too.
Next step is removing the bars. The bar that commands the right arm is anchored on the left side of the car and vice versa. We used a 2kg hammer and a thick walled aluminum pipe a little smaller in diameter than the end of the torsion bars. Then we hit the torsion bar of the right arm from the left side of the car (where it's anchored), so the bar went out through the arm. It took about 4 or 5 solid strokes.
Brute force does not help much here, make sure pipe is well alligned with the bar, so all the force goes axialy and hit it solidly. Aim well and hit it decidedly, the weight of the hammer will do all the work. Repeat the process on the other side.
With both bars out, proceed to clean teeth of the ends of the bars and their respective counterparts in the arms and the anchors thoroughly. Thoroughly means THOROUGHTLY. Every effort you spare doing this, you will pay later. I used WD40 a metal brush and later a pointy metal piece to scratch out every bit of rust and dirt. Then you oil/grease them well and try putting them back in without force. They will not go completely in manually, but they must engage smoothly at the beginning.
Then it's time to fix the new "lifted" ride height. Take out the piece of paper where you wrote down your measurements. Substract or add (depending if you´re lowering or increasing height) the difference you calculated form your last measurement. Then move the arm to the desired altitude, confirm measurement and hold it well in position. We used a little trolley jack below and some blocks of wood on the upper side to prevent it from going up. Then, with all in place, try to put the bar in manually. (NOOOO, don't hit it yet). It shoud go in smoothly. If it doesn't, turn it on tooth and try again. If it doesn't go in smoothly after turning and turning, you will have to readjust the height just a little bit and try again. Never put your hands near the ends of the bar during this process, always hold it from the flat surface. If anything should slip it could hurt you very bad. Once the bar goes in smoothly and you are sure the teeth of both ends are well engaged, you can go and hit it back into place. Repeat process on the other side.
Another note:
During this procedure, you can damage brake lines, fuel lines etc. Make sure you have all pipes and cables well identified and in sight and protect them properly well before hammering on anything.
Hope this was understandable and useful