Caster Shims

Best $30 I've spent (so far. LOL). I purchased a set and the longer bolts to go with them. I went to install them this last Friday and I found that V/S already had a set installed, so I just added the new ones (total of 2 each side). Took the car to Tech Night on Saturday and was REALLY pleased with the results. If you haven't installed these yet you really should and if you have 1 set you might consider a 2nd set.

you did an alignment after installing them, right?

You might also mention what the symptoms were before and after....

Yes! We need to know the entire story.

No caster or positive the steering will be tough , like driving a truck with manual steering. It will track straight . Adding negative caster will make steering easier. The shims that are sold for the VW will give you 3-6 degree negative caster that will make your turning more comfortable and not affect to straight tracking. I have them on mine .. and they are great.

Does anyone have a picture of these shims and where they are installed that they could post?

Mine is a VS widebody and it felt like every little bounce made the car want to jump a little one way or the other. After the install there appeared to be no change to the alignment.
They mount between the LOWER axle beam and the frame head.
They REALLY made a difference.
http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC%2DC10%2D4190

http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-C10-4190

Slipped in behind the front beam, and as mentioned, longer bolts are advised....

Fitting...

http://beetle.cabriolets.online.fr/tech/caster_modification.html

I have 'em in my "goodie box" waiting to go on.....Which I will do when the weather warms up a little, ( we are having unseasonable cold and snow here in Scotland...... -10 and 18" snow in the last couple of days...)

"there appeared to be no change to the alignment"

While you probably can't see it with your eyes - 2 shims each side pushed the lower part of beam our near 1/2" --- this would also affect the toe in-out which will cause abnormal tire wear on inner or outer edge. With little weight on Speedster front end it may take awhile for this wear to show. A realignement should be done.

If you look at the design of the VW front suspension it is one component. The steering box ,the torsion system and steering linkage is all bolted together on the front end. If you change the caster angle by installing these shims you will not change the toe in/out or the camber. If you are planing on install them use the proper grade bolts with some extra length.

Caster shims are installed on the lower beam and are used to correct the front end geometry when a car is lowered three inches, not using the shims will allow for increased difficulty steering at low speed.

When you add caster shims to the bottom of the beam, and it pulls away from the frame head, you VERY subtly turn the castor into camber. It's hugely subtle, but it is there.

What was once a degree of toe-in becomes an element of negative castor adjustment and effects the alignment minutely.

For me, I really like a LOT of extra caster for high speeds and even more negative camber for high . . . well . . . high speeds; especially in deep turns, like the sweeping on and off ramps. I like to sling shot into traffic and end up in the passing lane already at speed or greater and it takes a lot of negative camber to steady the car and allow for rapid acceleration through the ramp apex. A quick check of the side view and across four lanes to settle into the high speed groove.

Then the additional caster come into play, slows the steering a bit and removes all of the twitchiness.

SWEET.

So, anyway, yes. The caster, as it translates into camber, can effect the alignment, but for the better. I'd totally leave it alone. And drive WICKED fast. And if a cop stops you, hit him in the face with a shovel and tell him it's from me, would you?

"Hit him with a shovel"...Now there's our old TC :~) ~Alan

Troy asked for a a caster shim pix.

This is a bad pix, but the leading edge of one casster shim is just visible at the left side of the picture, on the bottom beam. It appears as a three inch long light colored shim between the bottom of the lower beam and the chassis mounting head. Because they are ALWAYS installed as a pair, on the lower beam ONLY, a similar shim is also barely visible on the right end of the beam.

If you've lowered the front beam, don't leave home without them!

I'm with Joe Soltis (probably because I'm sitting here with an exposed beam in front of me and can easily mess with it - and I bet Vince can come up with a good come-back for that one).

Anyway, adding the caster shims won't change camber or toe-in.

Put in one on each side and drive it. If they are like .040" slices of tubing, then you probably won't need the longer beam bolts. If they're thicker, then you might want the longer bolts - just make sure you have 1/2" of bolt threads going into the headset.

If, after installing them the steering feels good (easy steering and such) then you're done. If you're adventurous, try adding another one on both sides and road test it. If it's even better, good for you. If it doesn't markedly improve, then you can either leave it or pull out one on each side.

I'm running two on the passenger side on Pearl and one on the driver's side, mostly to correct a pan geometry issue and dial in the alignment the way I want it.

BTW: I think CB sells a somewhat thicker shim - like double thickness - than what I bought in the past from Berg or SoCal. They may subscribe to the "more is good" philosophy, or just got a batch that way, I don't know, but the last couple I got from them were pretty thick and non-magnetic. Just FWIW.....

Thanks. Now I know what I'm looking for. I'll crawl under there this weekend and see if they are already there. My front end is lowered, but I did it with 2.5" drop spindles. Should I still consider the shims?
Troy

Gordon,

I have a pair of shims from CB sitting in the top of my tool box. They do seem much thicker then i remember. Still debating whether or not to install them.

Troy and others: Your VS probably has 1 pair installed since I THINK Kirk does this automatically. If you look under the front of the car thru the wheel well from 1 side or the other you should see a shim on each side where the lower beam of the front end attaches to the pan frame head. They are probably aluminum and are appx. 1/8" thick at the thickest point. If you have one pair and the car still feels a little "twitchy" I HIGHLY recomend another pair. With our wide tires I really did not notice any more difficulty in low speed turning. To install, support the front of the car somewhere other than the front beam. Back one of the TOP beam attach bolts out ALL the way (to see how far out it will come). Then tighten it back in appx. 1/4". Next back out the other top beam bolt the same distance. Loosen the brackets for the bumpers/nerf bars as they will change relations to the body appx. 1/8". I recomend the longer bolts but they may have already been installed (they were on mine). Back the lower bolts out so that they are out appx 1/4". Use a pry bar to open the gaps at the lower beam and then slip the shims into place (it may take a little effort to keep the old and new ones matched).
Then tighten everything back up (don't forget the bumper/nerf brackets). It took appx. 40 min. and was REALLY worth the effort/expense.

"I'm running two on the passenger side on Pearl and one on the driver's side, mostly to correct a pan geometry issue"


That's a neat trick! I just shortened up a pan to fit under my little Fiat. Did the measuring, cutting, measuring, welding, and measuring with it up on the trailer. All leveled and as true as a man with glasses can make it, but it still might be a bit off once assembled.

Think that two shims, say one on the top and one on bottom tubes on one side might be used to bring the beam and rear torsion housing into true of needed? Or two even? Is there enough flex in the beam that I could use shims in the beam as you would on any front suspension, to bring the four corners into proper adjustment? Two on the top right, one on the top left etc., etc. This could be a neat fine tuning tool.

Never even occurred to me, until your post, that this sort of thing could be an option.

THANK YOU ! ! !

T

i spent several hours on a laser alignment jig and i ended up going with one caster shim on one side too. there is very very little flex int eh beam (plus i have a narrowed beam), but it worked out perfectly.

while you guys are in there and if you have a BJ beam, i'd suggest the camber bolts for the spindles. those little guys offered a lot more flexibility in alignment than without.

Yeah, I ended up with the wider camber adjusters, too. Couldn't get the left side within tolerance without them. Added them to the current build right from the start, even though I have drop spindles.

On TC's question; Yes, there is enough flex in the beam to utilize two or so caster shims and yes, you could, theoretically, put them in the top as well, but I can't think of why you would need them there on a lowered Speedster. On your Fiat Topolino project, maybe.....Or if a headset had been distorted or something.

Remember, you're forcing only the ends of the beam to flex (right where the mount sits), you're torquing the tubes over a 24" distance and you're forcing it only a very small amount (6-10 degrees at the wheel centerline) with shims only .050-.125" thick. Put those puppies in there and that beams gonna move.

Shimming the beam was a common fix for some older Beetles when they had suffered pan damage from accidents. If the pan wouldn't true-up after repair, you could shim the heck out of the front and rear ends (rear shims were called "wedges" and went between the wheel hub and the spring plate) to get them to track straight again. Rear ends really out sometimes required elongating the slots in the spring plates (and a lot of us have done THAT, too!)

gn

"Or if a headset had been distorted or something."

That's what I'm a little bit afraid of since I shortened the pan myself without a jig. A little bit off in the middle, by the frame head, is going to translate into quite a bit at the end of the spindle. I'll probable need a shim upper and lower on one side to square the front to the rear, plus two shims at the bottom to increase caster.

My thoughts (fears) anyway.

Hey Gordon, while I have your attention . . . I'm in the midst of rebuilding a pedal cluster for the Fiat and was wondering if you've even drilled/tapped and inserted a grease fitting in the bottom of the brake pedal. There's a ready made "slot" inside and a deep hole with a shallow fitting would clear everything and work pretty well to keep things lubed and loose.

Ever done it? Seems like it would work PISSA, but I was wondering . . .

Wha? (grizzle, grizzle, snort, snort....) Oh!....I was occupied elsewhere.....

Looks like you've missed Barry Hudson's posts elsewhere, but he and I (among others, I'm sure) pretty much always put a grease fitting on pedal clusters. It's so easy to do, but you don't want to put it on the bottom. Put it on the top, angled toward the seats a little so you can get at it with a gun tip.

After much under-Speedy crawling I discovered the problem causing the shimmy. The APE that built this thing welded flat stock over the front beam mounts. When this was done he gave it a 3/8" gap on top creating a negative caster by I don't know how many degrees. The right side had a washer welded in on top and bottom to equalize some other pan weld misalignment.
I replaced the washers with proper shims and then added one more set to the bottom so its a little better than "0" degree caster. Later I will cut out the welded spacers on top so it should be close to using 2 sets of shims on the bottom. Right now now its a lot better to drive at least. I can drive over 65 and feel pretty good, but I think I need more caster still.

The long mounting bolts were to short , I needed 150 mm which aren't available in 12mm 1.5 pitch, so I used 2 of the 6 main VW case studs and double nutted them, they were a little long but the extra nut took up the space.

And that, GB, is why it's called "the madness".

Madness is easily transmitted, you catch it from your car.

So, do you or do you not need to have an alignment if you add shims?
Troy

I would.

In fact, the best time to add them is when you're on the alignment rack and you can see what they're doing to your numbers.

I agree Troy and Gordon, I'm waiting til I have the top welds cut and reset,then I will get an alignment. It is already pulling to the left a bit. its like removing a rifle scope that is perfectly set and just bolting it back on it might be close but not right.