Hello
In the past, I removed rear camber shims from my car. Since then, trailing arm bushings have been replaced and I need to return the shim stack to its original thickness. I usually keep a record of such changes, but apparently I failed to record it or keep the old shims. I believe all shims were the same thickness.

Can anyone measure the thickness of a spare shim they have? Also, how many shims are installed at each wheel? I suspect all vehicles had the same number of shims, though not guaranteed. I have replacement shims from 914 Rubber which are of varying thickness, but I believe the original shims were all the same thickness.

Thank you.

Sincerely,
Shimless Jim

The shims are for alignment. Not a guarantee that you will use the same stack again when you align the car. Just order s stack and see what you need when you have it on the rack at the alignment shop.

Indeed. Van B is correct. The shims come in different thicknesses so see what you have and if you don't have at least 3 different thicknesses, I would order some and take them with you to the alignment shop.

Now....I would also recommend finding an alignment shop with someone who has aligned old cars like our cars before. I took my car to 2 alignment shops who claimed to know how to align the 914...it never felt right. Finally, I was referred to a guy in Roseville who had his own shop and knew what he was doing. Made a big difference in how the car rode and handled. 3rd time was a charm for me.

First find a good shop that can do a 4 wheel alignment
They are getting hard to find

Then take shims to the shop

Actually any car that has independent rear suspension gets a 4 wheel alignment these days. Today's alignment machines are built to do 4 wheel. Problem is finding one that can do our cars. I had mine done a few years ago and got under the car with the tech and walked him thru doing it. I had a box of shims with me. It came out near perfect

Also concur.
They often come in sets of 3 (2, 3, and 4 mm) IIRC. AA has them. They get stacked to provide the correct alignment.
Don’t forget to add the plastic plugs (often missing) to keep crud out of the open upper part of the bolt hole.
Click to view attachment

@StarBear you gotta link for where to buy those things?

914 Rubber has the full kit, not sure if they sell just the plugs. There is a chance you will need longer bolts depending how many shims you use. The kits contain those as well.

If you mean the plugs, I think both AA and 914Rubber sell them and maybe Pelican, too. They are similar to original but without the markings. If the shims, I think I got the kit with bolts from 914Rubber.

Depending on where in CA you are, Roger Kraus does full alignments and they do know 914s.
https://rogerkrausracing.com/

Just curious if any member has done the rear alignment at home.

Yes, i have. You're going to need a string setup, like the Smart Racing setup below for example.
https://www.smartracingproducts.com/smartstrings

It's a pretty tedious process, but it can be done on any level surface.


PS: For best results, you also want a way to corner balance the car before doing the alignment.

and ride height before Corner balance...

OK, now we need a breakout thread.

Ride height and corner balance have been on my list to play with for a while.

How do you corner balance w/o scales?

I have a set of scales...
if you ever want to come up and use them that is fine...

on the race car its at least a half day to scale.
like andy said about alignment.... also a tedious process.

changing ride height messes up your alignment... thus the order of things.


brant

You don't ...

I'd be willing to chip in 1/2 of the cost for a corner balance scale and string alignment setup if we can get someone with a nice red barn garage and lift ( @tygaboy ) to volunteer to offer alignment services to members.

Ride height, corner balance, alignment, got it. That's the easy part, the order that is...

I have a shop to use for the alignment that will shorten the tedious final process.

What's the thinking on ride height? Purely subjective or what?

Ride height is very much a personal preference until you get to the point where you bottom out the shocks. Not to mention bump steer.

- Eyeball the ride height to your personal preference

- Corner balance the car with ~1/2 a tank of gas and the drivers weight in the seat. For our cars the goal is right about 50/50.

- Align all 4 corners to match your intended use of the car

Awesome, I need to get some other things done. Contact you later. Thanks!

2 3 and 4 mm reduces neg camber 20 30 adn 40 minutes, we had precise ones made have at least 50 of each in stock as the Porsche factory discontinued them

@SirAndy - I have access to a set of scales and I'm working up an alignment set up for RacerBenz that'd work on essentially any car.
The Red Barn is always open and available to help in any way.

I think I would need to switch to a coil-over set up on the rear to be able to corner balance my car. It has never been done, but I would like to do that at some point. If I could do that with Chris at the Red Barn that would be a lot of fun. And, of course, I would donate to his car fund.

And a video too!

You already have coil-overs. What you need is adjustable perches for the coils to sit in.

@Cairo94507 Michael - Just putting your car on the scales would yield interesting initial data. It would be a nice to know anyway and provide a view into if there'd be measureable improvement in going to adjustable coil overs.
You might be surprised: We put @Markhoward Mark's 944 on the scales and with him in the car, it was essentially perfect. You just don't know until you check!

Note too, that you can adjust change corner balance via your front torsion bars: add a bit more "ride height" to the front left and you'll see more weight at the right rear. But again, it'd be fun just to get that baseline. If you'd be interested, let's talk about when.

And @NARP74 , I'd for sure capture the session and post it on the channel. It would support a recurring theme I'm working on introducing:

You never know who you'll meet or what you'll see... At The Red Barn!

@tygaboy - That's a great idea. Once we get some good weather, we will cruise on over once you have scales and see what we can see.

I have.

Its a lot less fun then doing the front alignment only.

But it is more fun than having an alignment shop put an air gun on the control arm bolts shearing one off in the chassis, which is what happened immediately before I started doing my own alignments.

I've done it too with a simple homemade string rig. It's fiddly and takes time, but my car handles great. I have a hard enough time finding someone who will do a good alignment job on our modern cars around here. Didn't want to gamble with the 914.

Years ago I need an alignment on my 914, around 1980. I took it to the local Porsche dealer thinking that would be my best bet. As I left the dealership I thought isn’t this great I’ve got the alignment set. I’m gonna head out on the freeway and see how it does. At freeway speed, I attempted a somewhat quick lane change. Almost ended up, spinning out the car, but thankfully saved it. Upon inspection, I found that the rear bolts through the shims were tight, only because they had bottomed out into the rust at the end of the threaded hole after a shim was removed, and not because they were holding the shims tight, or the rear trailing arms. I removed the top plug, cleared the rust from the threaded hole, and torqued down the bolt, so it was in contact with the shim plate.

And I forgot to mention it took two days for the alignment, because the dealer told me that their “914 alignment guy” wouldn’t be able to get to it quickly. Experience counts!.

My solution going forward from there was to do my own string alignment, until I had access to a 4 wheel alignment rack, and the skill to perform it myself. Now I can really set it up how I want, makes a world of difference.

Click to view attachment

The first time I cornerbalanced my race car I used a long handled square nose shovel. I went around the car and put the shovel under each wheel to compare the effort required to lift each corner of the car.

Out to mention this but we did the shims in stainless
https://914rubber.com/914-trailing-arm-shim-hw-kit

And yes I can sell the plugs alone, I'm getting listed up now.

Damnit man! why don't you mention that you did your shims in stainless!? Now I want a set of those instead!

You could use a spring scale on the end of that lever to get some usable numbers.

Stainless will get you a demerit with the Concours PoPo!

Luckily you’re safe.

They want to see the rust!

Yeah, we could make them Reg steel, but not much more to do it like we do and upgrade the product.

You could always plate the SS shims and coat with yellow chromate...

That matches what I measured, the 2mm shim changed camber by 0.32° and the 4mm shim changed camber by 0.65°.

Hi-tech!

Michael,
Who was the guy in Roseville? I live there and am doing a complete suspension rebuild right now.