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Sun Dec 04, 2011 5:56 pm

Now that I have my 1960 Beetle on the road I am getting to know its various nuances, and while I like most of them I have a few that are a little unsettling. The one that bothers me most is that my rear suspension sometimes feels like it is going to break loose when I'm taking a turn at speed. The feeling is especially prevalent when I hit a bump while cornering. It kind of feels like the rear wheels are wobbling. I have only driven IRS beetles until this one, so the sensation is unusual for me. Is this normal? If it isn't, is there something I can do to fix it? If it is normal swing axle behavior then should I be worried about losing control of the car? Info is appreciated. Thanks!

Sun Dec 04, 2011 6:52 pm

Swingaxles are definately less stable in cornering vs an IRS car.
The rear wheels jack up and you get more positive camber, like when the rear end of the car is off of the ground. You could find a camber compensator or lower it or just get used to it and corner slower.
I don't know that it feels like it's wobbling but it does make the rear end feel really light like you are about to lose control.

Sun Dec 04, 2011 6:58 pm

The irs and swing axle beetles handle very differently. Before we can help improve the handling we need to know more about your car. Is it lowered? and by how much? and what size tires are you running?

Sun Dec 04, 2011 6:59 pm

First thing is to make sure the car is aligned properly. Incorrect toe on either end can make the car real squirrelly. Now - a little more detail on your car would also be helpful. Stock height? lowered and if so how? Tire sizes, etc.

You may just have some set up issues.

Sun Dec 04, 2011 7:39 pm

After I flipped my first 67 while cornering too fast, I have learned to take turns a little slower. That's been 25 years ago and I haven't flipped one since. Been driving swing axles ever since also.

Sun Dec 04, 2011 9:31 pm

I have my car setup completely stock. Tires, height, everything. I took apart the whole rear suspension in the process of restoring the car, so I'm starting to worry that I didn't have something lined up correctly. I'm not really scared of this issue because at low speeds it is just a little uncomfortable, but what I worry about is what it will do when I'm doing 60 and hit a bump.

Sun Dec 04, 2011 10:04 pm

I'd say you have an alignment, tire or wear issue somewhere. A properly set up swingaxle bug is not a sports car, but is stable and predictable. What tire pressures are you running?
My current bug is a swingaxle, lowered, with extended spring plates. Solid as a rock in corners.

Sun Dec 04, 2011 10:05 pm

An IRS and a swing axle definitely handle differently. I have owned a 1970 bug that is stock with a 1600 cc engine for 26 years. Last year I bought a 1960 bug. It is also stock, new radial tires and shocks and tight and aligned front end. It had been a long time since I had last driven a swing axle bug and I had to adjust my driving habits a little. Of course the 36 hp engine helps you in that process. I would say I definitely take the corners slower, and roads that curve in the 1960. I am not sure I would say it feels like it is "wobbling" though upon hitting a bump on a corner. The swing axles do handle differently and require a little more care and attention while driving. Are your shocks good?

Mon Dec 05, 2011 5:09 am

If you had the rear apart, you need to verify the toe.

Mon Dec 05, 2011 9:37 am

The swing axle VW is one of the most evil handling cars on the planet! Why? Because all 4 wheels are trying to steer in different directions and to make matters worse, where they are trying to steer changes as the suspension moves up and down.

A few things to keep in mind... One of the worst things to happen is the rear wheel to tuck under heavy cornering. When that happens, it instantly jacks up the car and puts you on your head.

When driving, you really need to be aware of this. NEVER enter a corner too fast! Once are in the corner, you have to keep power to the wheels. That power makes that loaded wheel want to drive out and that keeps it from tucking under.

If you go in too fast and don't have enough power in reserve to pull you all the way through the corner, well, you can easily end up on your head.

At the same time, if you ever get scared and lift your foot off the throttle in a corner - even for just a split second, it may be Adios time.

There are a few things that can help this. In 67, VW made several changes to the previous set up. They lowered the rear ride height. And they installed the Z-Bar which they marketed as a "helper spring".

It was a helper spring, but a much more important function was to try to lessen the wheel tuck. They couldn't really mention that in their marketing materials without putting the word out that they had been producing an ill handling, dangerous car. So they called it a helper spring.

At the same time, they changed the front wheel alignment specs to have more positive camber. This promoted understeer which was far easier for the motoring public to recover from then oversteer. It also helped to keep the car from getting into a situation where it would oversteer enough to suffer wheel tuck.

Doing a rear wheel alignment on a swing axle is difficult because the axles are almost never level with the ground. In order to set toe, you need to jack up the car, or load the car until the axles are both level with the ground and then measure and set your toe.

And even then, this is just a starting point. Depending on the ride height of your car, you may need to add more or less toe in order to get a comfortable and safe ride.

It is also very important to keep an eye on your tire pressures. Low tire pressure can cause a lot of problems, and the swing axle makes then even worse as the camber and toe change as tire pressure goes up or down. And even a little change in tire pressure can have an effect you can sometimes feel going in a straight line if you pay attention enough.

So start with trying to check your rear toe settings and alignment. Get that straightened out first. Then if it still feels bad, you may really need to install some caster shims up front.

Also check your rear tranny mounts! They are often over looked. They keep the engine/transmission assembly centered in the car. If they are bad, they allow that mass of the engine/transmission to move around side to side. That drastically changes what the rear wheels are doing in relation to where they are steering!

Mon Dec 05, 2011 12:43 pm

My 62 is lowered several inches in the rear, and when my rear wheel hits a bump (or more specifically, a hole), it pulls the car to one side rather abruptly.
I don't know if this is your problem, and I know you said your car isn't lowered.
Maybe someone with experience driving both lowered and stock height cars can chime in. It was pretty unsettling when I first experienced it, but now I barely notice it.
A new passenger will always comment though! :shock:
I agree about rear toe, set it as best you can. Also, just keep fiddling with your setup and checking stuff, you'll sort it out eventually...

Mon Dec 05, 2011 1:01 pm

drscope wrote: The swing axle VW is one of the most evil handling cars on the planet! There are a few things that can help this.

In addition to the things you mention, you could add a camber compensator.

Mon Dec 05, 2011 1:31 pm

Real good advice in this thread. It boils down to 3 things.
1) Make sure mechanical condition and all adjustments of both front and rear axles are A1.
2) Keep tire pressures dead on.
3) Remember what you are driving and its limitations. Very, very important.
Years ago a friend of mine bought a 68 bug. He previously had only owned and driven full size American cars. I rode with him in his new bug once. A few months later he rolled it and totalled it. No one was injured. He took a corner too fast and rear wheels tucked in and over it went. I always felt a little guilty that I had not reminded him when riding with him that time, that you are driving a VW beetle, not a Mustang, Camaro or Corvette or even the General Lee on the Dukes of Hazzard.

Mon Dec 05, 2011 2:37 pm

One thing that is very important to rmember when driving a rear engined swing or IRS axled car.... Do ALL your braking BEFORE turning into a corner.

I rebuilt an engine for a customers '77 930 turbo and went with him on the test drive when he came to pay for it, While blasting doen a side street he decided to turn at the last minute so pounded on the brakes and started turning at the same time......as we went backwards over the curbing, destroying his brand new $1800 stainless exhaust system, I reminded him AGAIN of that exact thing

brad

Mon Dec 05, 2011 3:43 pm

79SuperVert wrote: drscope wrote: The swing axle VW is one of the most evil handling cars on the planet! There are a few things that can help this.

In addition to the things you mention, you could add a camber compensator.

I was going to mention that when talking about the Z-Bar, but it was forgotten in all that long dribble. Too many interruptions here today!

Mon Dec 05, 2011 8:13 pm

When you had it all apart, did you also replace inner and out springplate bushings? If not, even if the rear toe is set properly to begin with it can change if the bushings are worn. As the wheel goes up and down with its axle arc, the toe changes and make the car real squirely (more so in corners)

Mon Jun 24, 2024 7:58 pm

Specific to my vehicle, parts, experience: 67 dune buggy with hd swing plates, highly torqued with min step welded to maintain almost level appearing underswing, 15" tires, 70 series, cornering is rather non dramatic, little body roll, drives otherwise very well. Coil over front shocks, reg gas rear.

But, take a corner fast and kick it a little it'll break loose and swing out like a go cart would. No tuck or flip threat or sensation. Aligned and running 25 lbs rear, 20 front (it's light). Intentionally kicked out on a turn the turn had a high side to it when engaged, did a 1 1/4 revolution donut coming to stop, took about 2 seconds to occur. Scared the #$()(#$ out of my guest and self, not in a bad way, it was a tight donut.

I understand there's 2" add'l axle width due to year, the make up of the components, the light weight, tire size and pressure result in a very fun and not threatening ride; slides corners if level road; noticed swing plate warped a little.

Mon Jun 24, 2024 8:52 pm

Marktt wrote: Specific to my vehicle, parts, experience: 67 dune buggy with hd swing plates, highly torqued with min step welded to maintain almost level appearing underswing, 15" tires, 70 series, cornering is rather non dramatic, little body roll, drives otherwise very well. Coil over front shocks, reg gas rear.

But, take a corner fast and kick it a little it'll break loose and swing out like a go cart would. No tuck or flip threat or sensation. Aligned and running 25 lbs rear, 20 front (it's light). Intentionally kicked out on a turn the turn had a high side to it when engaged, did a 1 1/4 revolution donut coming to stop, took about 2 seconds to occur. Scared the #$()(#$ out of my guest and self, not in a bad way, it was a tight donut.

I understand there's 2" add'l axle width due to year, the make up of the components, the light weight, tire size and pressure result in a very fun and not threatening ride; slides corners if level road; noticed swing plate warped a little.
Sooooo!
What's the question?

Run the front tires a little lower pressure, so they grip a bit better. I run 16-17 lbs. in mine on a stock bodied 67.

Have you considered a set of bronze spring plate covers to keep the spring plates aligned?
https://ronlummusracing.com/product/spring-plate-retainers/

Tue Jun 25, 2024 11:27 am

67rustavenger wrote: Marktt wrote: Specific to my vehicle, parts, experience: 67 dune buggy with hd swing plates, highly torqued with min step welded to maintain almost level appearing underswing, 15" tires, 70 series, cornering is rather non dramatic, little body roll, drives otherwise very well. Coil over front shocks, reg gas rear.

But, take a corner fast and kick it a little it'll break loose and swing out like a go cart would. No tuck or flip threat or sensation. Aligned and running 25 lbs rear, 20 front (it's light). Intentionally kicked out on a turn the turn had a high side to it when engaged, did a 1 1/4 revolution donut coming to stop, took about 2 seconds to occur. Scared the #$()(#$ out of my guest and self, not in a bad way, it was a tight donut.

I understand there's 2" add'l axle width due to year, the make up of the components, the light weight, tire size and pressure result in a very fun and not threatening ride; slides corners if level road; noticed swing plate warped a little.
Sooooo!
What's the question?

Run the front tires a little lower pressure, so they grip a bit better. I run 16-17 lbs. in mine on a stock bodied 67.

Have you considered a set of bronze spring plate covers to keep the spring plates aligned?
https://ronlummusracing.com/product/spring-plate-retainers/

Wouldn't less pressure in the front (better grip) increase the likelihood of the rear stepping out?