To be accurate, it is a 1960 chassis with a 1968 transmission, 1962 spring plates and type-3 drum brakes, but far as i know all the 60's bugs are very much the same as far as this is concerned. The wheel of a swing axle doesn't travel anywhere near straight up and down, but rather travels in an arc. Therefore actual ride height measurements are difficult, and also they change with the size and offset of the tire. SO, I found it is easiest to just measure the travel and ride height in degrees of camber. The angle can be measured at the axle tube or the brake drum or the wheel, they are all connected together so it doesn't matter. Zero degrees camber or perhaps up to 2 positive camber is usually considered the "stock" ride height. With the torsion bar removed, but all else assembled, I measured the travel.
Extended: 8 degrees down shock length 16.5" When rubber bump stop comes into action: 5 deg up
When the spring plate hits the hard stop:9 degrees up shock length 10.5"
I have always wondered how much the UP travel can be increased.
So, I then put on these "complimentary" special spring plates that go around the hard bump stop. This is all the way up, note the "hard stop" is still nowhere near hitting the spring plate.
This allowed it to travel up another 2 degrees, however it seems that this is all the travel the transmission allows, at this point the internal joint runs out of travel. I jacked it up a bit more but the engine started twisting.
Shocked I tried the tire on it and it DID clear everything even at 11 degrees up.
PRO's edit: This point must be made as it is not talked about enough. “Drop Plates” do not take in a effect what the user just stated about the transmission internal pivot point runs out of travel. It only does the outer point and hammers the transmission components. And this is only with 1.2” drop plates, we haven’t even discussed the 3” or 4” drop plates. Just because people/kids/shops make them, doesn’t mean they wont harm other components. Just like taking a pill to help with a headache and the side effects are you now have diarrhea. Are you okay with that? We haven’t even discussed what happens to the eBrake cables, your drum brake applications or the shock complications you will have. More extensive right up will come on those shortly.
So, these 1.2" lowering spring plates changed the travel thus:
Fully extended; 6 degrees, shock length 14"
Fully compressed; 11 degrees, shock length 9 3/4
The inner side has less splines than the outer. This means that if you move an inner spline, it changes it MORE than if you move an outer spline. By moving one outer and one inner, the ride height can be adjusted in about 1/4 inch increments. So, first off you must make sure the torsion bars will go by hand into the plate and car, otherwise it will be hell to do this.
There are four different rubber bushings, you need one of each, they have thicker side that is supposed to go UP, and two different hole sizes for inner and outer. It can be difficult to work them into place, I have a solution, lube them with silicone oil. You all know what happens when you get grease or engine oil on rubber...... but this oil will not harm it. The silicone spray may work, but I like to use thicker stuff.
So how to get them at the right angle? (height)
Now, in the past I have tried to just do this with a tape measure, BUT, when the spring plate is not all the way in place it wiggles around and makes this impractical. Better to go by angle, using the angle finder pictured above. The service manuals list the angle they are supposed to be installed at. Sway-a-way has the info for the other sizes of torsion bar.
Setting the spring plate on the torsion bar and taking degree readings would be perfect if wear/tear or relaxation of the torsion bars have occurred. If we are talking about a new vehicle, with no where and tear, this post is 100% perfect.
What I tend to mention to my clients is measure the degrees under a load. Placing a jack under the spring plate and as it starts to lift the car, take that degree reading.
For example; ( If a 500lb man delivers mail in his 64 Beetle and drives 100 miles a day, the wear and tear on that side of the vehicle is going to be more than the other side. Take the same instance but with a 100lb woman and 10 miles a day, the under the load readings will be different for both cars. Static measurements will show the same, but under a load will be different, sometimes substantially.)
So, in my case it says 8.5 degrees for the 26mm bars. I want to go a bit lower, so I will try 6 degrees. This angle is with the car level, so you either have to level the car, or just measure whatever angle it's sitting at and figure it in.
I go in and measure the angle of the frame tunnel as the car sits on the jack stands
(Edit from post - Put a jack under the spring plate to get an under a load reading) (….. 3.5 degrees rake........ 6 minus 3.5.... So I want the spring plates to measure 2.5 degrees down.....get it?
So just stick the torsion bar in there, and put the lubed rubber doughnut on the plate, and stick the plate partway, on close to where it should be and measure the angle.
Of course it might be way off, take the plate off and pull the torsion bar out just enough to be free of the splines, rotate it a spline or two the same.
Once it is where you want it, push it on as far as it will go,
use this tool for safety and raise the spring plate up over the lower stop. Make sure you have safety glasses on before the next step. At this point I like to take a 2x4 and a sledge hammer and push the spring plate the rest of the way in.
I managed to get it to 2.5 degrees, (which is actually 6 relative to the car).
Another point that needs to be made, these cars from the factory had positive camber as you have stated somewhat in this thread. After they wear in and get some miles on them, the car starts to relax. And eventually, they almost have no camber. Regardless of the aftermarket parts that you install, you should still note that the car is now lowered in ride height and is no longer stock height. Most cases should reflect, 6.5-7" of gap between the top of the tire and the bottom side of the fender. Roughly with 2" of tire gap left, should reflect 0 degrees of camber.
The right shocks can be critical in making these cars ride and handle amazing. Make sure you install a set of correctly valved shocks to finish this process off nicely.
Also, make sure you get a 4 wheel alignment after your finished. This will ensure that the rear wheels are evenly spaced to the front wheels and will help with wandering on the road.
Torsion bars - Round bars which twist under load providing the "spring" for your suspension. Mounted crosswise and horizontal forward of the axles just under the back seat area of the floor pan. Cover plates - These cover the outer ends of the torsion bars and hold the torsion bars in place using large rubber bushings. Spring plates - These large flat spring steel plates connect the axles to the torsion bars. On the newer IRS models these plates simply move up and down but on the older swing axle models the swinging motion makes the spring plate twist as they work up and down. Axle assembly - This is where the spring plates bolt to the axle and they also hold the brake assembly in place. Tools - You'll need a good jack (this job can be done with a hydraulic bottle jack or screw jack but it will take more time) axle stands (preferably 4 of them for front and rear) box wrenches a file or cold chisel two extra large screw drivers or a set of tyre levers and a lazy afternoon.
Raise the whole car off the ground (measurements are easier with the car level and you need some working room under the rear). Make sure it's well supported - you need to do some pushing and pulling at the back. Axle stands under the front and rear torsion bar tubes work best.
Remove the rear wheels.
Examine the spring plate ends where they meet the fitting on the axle end. The spring plates have elongated holes so you can set the rear suspension toe-in.
Check to see if your car has had adjustable spring plates (after-market item) fitted. These have an adjusting bolt and an 'additional' short plate nearer the torsion bar end of the spring plate - front of car end). If you don't have these additional fittings you have the original non-adjustable type which must be rotated.
Remove the three bolts holding the spring plate to the axle assembly. These are large bolts and have a lot of torque on them and not a lot of room around the bolt heads. You need good box wrenches (ring spanners) rather than the open-end type or you risk rounding the bolt heads. The spring plate is 'twisted' as the suspension moves through an arc (swing axle models) so you'll see it 'untwist' as you undo these bolts. This keeps the bolts under some tension - they don't just come loose and spin off. There is probably a rubber bump-stop attached to one of these too - take note of how it's mounted so it can be replaced the same way. 67-70 manual transmission swing axle models also have an anti sway bar linkage attached to the axle with these bolts too - remove this mounting. You should then be able to maneuver the whole axle towards the rear of the car free of the spring plate without loosening any of the brake lines etc. You might need to tie it back clear of the spring plate. If it won't move back far enough you may have to loosen the hand-brake cables. Do this from inside the car - pull up the rubber boot over the hand brake and remove the horizontal balance bar between the two cables. Now the axles can be pulled back and the cables will pull out of their sheaths slightly as they follow the axle.
Now look at the front of the spring plate. There is a cover plate with four bolts. Remove these and pull off the cover. There is a large rubber bushing underneath and you should now be able to see the splined outer end of the torsion bar.
Now comes the interesting part. The spring plate is still under considerable tension and will be sitting on a stop-lip - a lip just to the rear of the torsion bar. If you try to lever the spring plate outwards it will fly downwards with a big thump (breaking any arm or leg in it's way) so it's better to ease it down. Place the trolley jack (or a bottle jack will do) under the axle end of the spring plate and jack up the spring plate just enough so it is just free of the stop-lip.
Now carefully lever the spring plate outwards about 1/2 inch using very large screw drivers or tyre levers top and bottom working at the torsion bar end. Once clear of the stop-lip you can then lower the jack and the spring plate will drop a lot lower past the stop-lip (this is why you need the car up off the ground).
Leave that side and attack the other side now so you get both spring plates hanging free on their torsion bars.
Measure the distance between the ground and the axle ends of the spring plates so you can judge the effect of the adjustments. VW recommend an inclinometer here with different angles for different models but you can get it pretty good just by taking note of the height from the floor to the rear end of the spring plate. The torsion bar has 40 splines on it's inner end and 44 on it's outer end. VW designed it this way so you can make fine adjustments to the angle of the spring plate (ride height of the rear end of the car).
Now working on one side or the car at a time you pull out the spring plate WITH the torsion bar until it is free to rotate (about 1 inch or so). Might be a bit fiddly as the assembly might stick a bit on the inner rubber bushing around the torsion bar end. Then rotate the whole spring plate AND torsion bar downwards by one (inner) spline and push it back in. This increases the spring plate angle by 9 degrees which is too much so you now pull the spring plate off again but this time push the torsion bar in (you can see the end of it remember) so ONLY the spring plate comes loose. Now rotate the spring plate alone upwards one (outer) spline. This decreases the spring plate angle by 8.1 degrees for a total angle increase of 0.9 degrees. The axle end of the spring plate should now be a little closer to the ground (which of course raises the car on it's wheels).
Do the other side similarly. You'll have to judge how many times to do this rotation trick But usually one "rotation" is enough. Two rotations might be needed for a really sagging rear end. If your spring plates were hanging at similar heights before you started (point 7 above) it is easier as you simply match the rotations side for side. If they were at different heights you'll have to decide which setting you like on one side and then match the other side to it. It is ESSENTIAL to get the sides matched fairly closely in height otherwise the car will 'squat' on one side. (Adjustable spring plates are useful here as it is then easy to fine-tune the angle of each side). Note: The spring plate angle should be about 20-21 degrees but this does vary from model to model.
When you are happy with the settings bolt the cover plates back over the torsion bar ends (pulling it in evenly with the bolts so the rubber bushing is not distorted). Be careful here as you need to pull the spring plate up just snug against the stop-lip then jack up the axle end until the plate is higher than the stop-lip then tighten the cover plate fully so the spring plate will rest on the stop-lip when you release the jack. DON'T try to jack the spring plate up before you start fastening the torsion bar cover plate - the plate must be partly secure BEFORE the spring plate is raised or you'll never be able to start the bolts in the cover plate.
Then remount the axle assembly at the rear end - being careful to line up the toe-in marks you made previously. Don't forget the bump-stop and any other attachments at the axle end.Note: Don't forget that the spring plate will be 'twisted' again as you do the bolts up (swing axle models) - I found it easier to install one bolt (where the spring plate and axle assembly are closest - bottom bolt I think) first and tighten it up to start the 'twist' and you'll then be able to spin on the other bolts on a little easier. Lining up the toe-in marks might require some hefty wacks on the brake drum nut with a rubber mallet or block of wood (DON'T use a metal hammer please) as snugging the bolts up twists the spring plate and makes it quite a tight fit even before you tighten the bolts completely. Don't forget to reattach your hand brake fittings inside the car and adjust the horizontal balance bar between the two cables so the hand brake pulls evenly up 3 to 4 clicks.
Once the car is back on it's wheels you have to roll it back and forwards (or drive it a few yards) for the swing axles/wheels to move into their 'natural' position and you can then check the height of the rear end. The axles should be close to parallel viewed from behind - perhaps just a slight wheel-end-down angle (slight positive camber) with the running boards parallel to the ground (assuming that the front suspension has not been altered).
There is the possibility that you will need to do it all again if the suspension angle is still not right.
Please understand that this article shows you how to lower the vehicle with nothing else purchased, just labor.
If you want to do it right, there is a list of parts that will make it perfect.
Lowered Shocks - Once you have lowered the vehicle the travel in the shock has changed. Getting the right shock means no more bottoming out because the travel is limited with the shock.
Adjustable Shocks - Ride quality, MyFit - My fit - Your idea of soft is this and my idea is this. With an adjustable shock, your fit is available with a twist of a knob.
Modok for the time and effort you put into this write up.