Ok all you racer and strut front-end guy's. who knows what options are out there to increase the caster on the front of an L-bug. I have one here with the shimmy @ 80 clicks and the front-end specs are way off, problem I see is how to get it back in spec....

It's been a while since I've repaired one of these issues and was wondering if there were any new products/ideas out there that may help.

Are you sticking with the stock sway bar?

Topline in California sell caster fix bushings which pull the swaybar forward to correct any changes in caster.
They are available for both stock and 3/4" swaybars and are urethane so will outlast the car.

if the camber is way off too they also sell Camber plus control arm bushings which do the same thing.

Awesome Joel, thanks. That's what I need, an offset front bushing. I knew someone had posted here with the info, but of course the search brought up zilch. Now to find them on the interweb.
Thanks for being soooo speedy mate

No worries,
this is the one you need for a stock sway bar

http://toplineparts.com/caster-fix-bushings-for-stock-sway-bar.html 

Thanks mate, yep stock bar and already in my cart, with a well priced strut brace too.

They work a treat.
Had them on minw

Matt I fitted Topline offset caster bushs to my Hillclimber and was a little disappointed. Only gained approx. 1/2 degree positive caster.
I,m currently in the process of modifiying a thicker bar to gain more caster, will let you know how it all works out when I can.

Cheers Col

Hi Matt

Regarding the shimmy, I'm convinced that its caused by the front spring rate being too soft.

My sons bug has had skinny struts with heavier springs almost since got it.

Over that time its had flogged out sway bar and control arms bushes, worn tie rods, worn steering universal, worn tie rods, worn lower ball joints and worn drag link, all at different times I might add and its never had shimmy.

Steve

Thanks Col, I've had to email the order so haven't finalised it yet. That sounds disapointing but I think I'll go ahead with it as every little bit will help. I'm looking for 1 degree, ideally 1.2 so I guess I'll be chasing everything I can get.

My sway bar came from Boris at Vintage Vee Dub, he & John Ladomatis designed it. It has adjustable caster washers on it. I run 3.3d caster on mine.

Also never had front end shimmy on my Superbug in 24 years of owning it.

3.3 deg is some caster for sure. Interesting to hear Jak that you've never experienced it. I've worked on many of these issues over the years and I wish there was a common cause. Very interesting theroy of Steves too. I have always felt the wheel balance/trueness has to be the initial cause and caster the thing that keeps it all under control, but as with anything car related, it seems no one thing is always to blame. We learn everyday, and that is certainly true with these cars, always something. I say this because in the last few years, I've also had issues with two b/j beetles having the same shimmy dramas......it never ends...

Thanks for your suggestions fella's

I also forgot to mention Matt that my front wheels I've always had balanced on the car, so that brake rotor & wheel are balanced as one. Same with my track/race wheels.

Don't know if this helps or not or if I'm just being pedantic.

topline parts recommends a replace kit for supers as pretty much every bush etc must be worn ,rotted, soft.
as the car is 40 years old.

I have fixed one with shimmy by raising the back end back up to correct ride height and it seems to put more weight back on the front wheels where it should be .

Thanks again guy's. I agree with all above.....on-car-balance was the ONLY way I cured probably the worst case I can remember back in the early 90's. 14" Globes on a can opener convertible, absolutely everything replaced, Super-Pro everywhere, all new ends......to no avail, until the on-car balance.
I too have had results with raising the rear, but this particular vehicle has a good ride height. Just no strut brace or caster.

Hi

I used to have to get on car balancing when I was running 14" Magnum Eliminators on my yellow bug, haven't needed it for years.

Steve

what is the front and rear wheel alignment spec anyway???
as I fitted 6 inch fattys on my super

This might sound like a stoooopid idea (Not unusual for me! ), but I thought for my 1303 a set of bronze swaybar front mount would stop ANY shimmy, but with rubber/Nolathane arm bushes still allow a bit of stress relief. I figured that keeping the front wheel where you want it would be a good thing.
Of course if you snap the bloody bar or crack the mounting rail then it might have it's disadvantages!
Anyone tried it, or heard of it?

The main fault with the strut front end is the length of the control arm and the fact they are only single pivot point.
Look at any modern mac strut car and you'll notice the control arms have 2 pivot points and are about half the length.

The bushings have a much bigger job when there is only one pivot point and any play in them becomes much more apparent.
This vid shows perfectly what happens.

THe owner only had them replaced 6 months earlier.



That is where urethane bushings really shine, stock rubber are just too soggy.

I fully agree with Steve though firmer springs make all the difference, stock ones are made for comfort and are way too soft.

All those old 70s and 80s mags are also shocking for causing it as nearly all of them use square shank bolts rather than ball seat so they never mount up true.
When I first bought mine and put hotwires on it shook like no tomorrow till I put stockos back on.
My springs are 135lb, stock is 75lb.
I havent had a shimmy problem for 14 years even with rooted draglink, ball joint, tierod end and steering damper bushing.

its probably worn out strut inserts and out of balance wheels that puts all that extra load on the bushes.
fat tyres would do it to added more sprung/ unsprung weight .
I only ever felt it on a standard 36 year old super bug.
that guys vw also sounds like it got a leaking head .
ps I wonder how long it took the brand new super bugs in 1971 to get the shimmies before being taking back for warranty as the roads were not as good as they are these days .????

Wow, those control arm bushes are really stuffed. Check out the movement just under driving fwd, which throws the alignment which then accentuates the problem. Vid also shows up a great example of loose heads, cold the heads are flapping off the barrels and as some heat gets into the barrel the heads tighten up and stop flapping so much. He's light on the throttle so they don't sound soooo bad initially.....

Specs I've listed below, but one interesting thing is your spring spec Joel, my std listing is one of three groups depending on colour code but essentially from 227kg (500lb) to247kg (545lb).

Front

Toe 30' +- 15'
Camber 1 deg +- 20'
Caster 2deg +- 35'

Rear toe

0deg +- 15'

(there is a heap of other specs for checking pressed and unpressed suspension deviations etc etc but above are the basics)

Quote:

Originally posted by modnrod This might sound like a stoooopid idea (Not unusual for me! ), but I thought for my 1303 a set of bronze swaybar front mount would stop ANY shimmy, but with rubber/Nolathane arm bushes still allow a bit of stress relief. I figured that keeping the front wheel where you want it would be a good thing. Of course if you snap the bloody bar or crack the mounting rail then it might have it's disadvantages! Anyone tried it, or heard of it?