VW THING Torsion Bars, Type 181 Torsion Bar Specs

[randybriscoe]

Here is my stock, VW THING, Type 181 rear suspension going together. Follow along, if you like. The torsion bars are approx 625mm long.

[randybriscoe]

Here's the length, as measured. I think these are what most people call the intermediate length bar. They are approx 625mm long. So from now on, lets call them "625's". OK, awesome.

[randybriscoe]

The factory bars measure 24mm in diameter.

[randybriscoe]

When the torsion bar is fully inserted, this is how far they stick out.

[randybriscoe]

We are fortunate to have these NOS spring plates for the install. Note factory tag.

[randybriscoe]

This is what they look like inside. So clean, it's a shame to use them really. But it makes adjusting the bars so much easier.

[randybriscoe]

Now it's time for the inner rubber bushing, try not to get anything on it that's going to chemically effect the rubber (in a bad way).

[randybriscoe]

Here's the rubber bushing properly installed. We were very careful not to get any grease from the splines onto the bushing. Here's a thought...maybe next time we'll grease the splines after we install the bushing. Genius!

[randybriscoe]

The bars are marked Left and Right. Now grease up those torsion bar splines. Slide/press the spring plate onto the splines, while forcing the outer diameter of the spring plate through the bushing. It's a little bit of a force fit, we used silicone lube to make it easy.

The picture shows how the spring plate fits onto the outer end of the torsion bar. I guess you could assemble everything (torsion bar to plate, add bushing) off of the chassis, and then just insert the whole assemble. Either way.

[mondshine]

Looks good Randy-

Are those OE torsion bars, or Thing Shop repro's?

Looking forward to the next "chapter" where you set the spring plate angle.

Good luck, Mondshine

[mondshine]

Just one more detail...
Be sure to touch up those scratches in the paint before you button it up to prevent the bars from rusting.

Good luck, Mondshine

[randybriscoe]

Well, up to now it's been stupid simple. But now we need to do some measurements/calculations.

As you know, the inboard side of the torsion bar has 40 splines, and outer side has 44. Indexing or setting your pre-load is explained on many web pages, so I'll skip over most of that detail.

Here's some important "things" to remember:
1. Get the chassis level with the compass.
2. Figure out how many degrees of pre-load you want.
3. Moving the inner spline position one click, is worth about 9 degrees.
4. Moving the spring plate one spline back, the opposite direction, takes away about 8.18 of that 9 degree move.
5. So moving one spline clockwise, and the other spline counter clockwise, one spline at a time, together, gives you almost a full degree of movement.

We set ours at 23 degrees pre-load. We don't know the factory spec for the 181.

[randybriscoe]

With the pre-load set, now we use our spring compressor tool to lift the swing arm onto it's "stop" or perch. The tool wanted to slide down the spring plate, so we ended up putting a clamp on the plate to prevent this. A lot of energy is built up during this process, so this is potentially dangerous, so use caution. Or let your friend do it.

When the spring plate was lifted high enough to clear the stop, we drove the the assemble on with a large, soft mallet.

[randybriscoe]

OK, good job. Everybody still have all their fingers? Now the spring plate is sitting on the down stop (rebound). Be carefull, it can slip off of here easily. Now all that energy form the twisted torsion bar is pushing up on that rubber bushing. Right?

[randybriscoe]

Final rubber bushing in place. Now we need a spring plate cover.

[randybriscoe]

Yes, these are THING SHOP torsion bars. We wanted to try them out. They are identical to the factory bars.

Yes, scratches in that special twistable paint, can lead to trouble. Any corrosion on a spring can lead to failure. Or can it?

[mondshine]

Thanks Randy-
I will be curious to know how the body sits (at 23* preload) once your car is re-assembled, because I have a set of Thing Shop torsion bars waiting to go on this Spring.

The Thing Shop claims "We had them made TOUGHER!", and I am wondering what that means re: the preload angle.

If you get the car put back together before May, please report back whether 23* was right for the body to sit level.
(Hey...Chicago isn't far from Dayton, hope to see you there this July.)

Thanks, Mondshine

[citroen]

Gary we are also putting a set in the next Thing Shop Project we will see how they do in that one.

[mondshine]

Just to resurrect an old thread, I picked up a 181 workshop manual a couple days ago at a swap meet. I believe this is a Thing Shop reprint of the original manual; it is 3 hole punched, in a loose leaf binder.
Anyway, when I turned to the section covering the rear torsion bar pre-load angle, I found something surprising.

Somebody has hand lettered 27* as the pre-load angle!

So, my questions are:
Is this unique to my copy of this manual?
Has somebody pasted over the true figure?
Is this a Thing Shop alteration to the manual?

If anybody out there has this manual, please check page H 7.2

Ron & Dennis- How did it go with your installation of those Thing Shop repro torsion bars?

Thanks, Mondshine

[Ron Domeck]

That Thing is next in line. Still will be a month or so on the current build. Life and weather gets in our way.