View Full Version : Lower Control Arm Shim question

09-07-2017, 07:46 AM
I recently re-did a portion of the front end on my 59. Replaced the ball joints, tie rod ends, and did some rehab to one of the control arms which had a small crack and a broken shock retainer. This was months ago and I really haven't drove the bird too much since then, it lives jacked up in my garage.

So the other day I had noticed that I had some washers that I remember that fit in FRONT of the lower control arms. So i went out yesterday and dropped the coil spring and lower control arms back out so I could install the shims.

I noticed that while it takes 1 shim on the passenger side, it takes 3 on the drivers side. That's how many total I have is 4 total shims.

My question is, is this normal for one side to be shimmed more than the other?

Current arrangement
Drivers side FRONT lower control arm 3 shims
Passenger side FRONT lower control arm 1 shim

I know not to tighten the control arm mounting bolts until the car is lowered and weight is on the vehicle, but I haven't done that yet as I ordered a master cylinder from a 68 mustang with drum brakes that I am going to retrofit onto the bird just so I can actually go for a drive.

Thanks in advance, its a lot of work tearing the front end all apart for a couple stinkin washers. https://scontent-ort2-1.xx.fbcdn.net/v/t1.0-9/1005504_10154430537184256_5747781876873178872_n.jp g?oh=51adb47f17cd370eaa89986dac292c70&oe=5A60FEDF
https://scontent-ort2-1.xx.fbcdn.net/v/t1.0-9/260414_10150359741329256_3567788_n.jpg?oh=2b903bd5 06ee930f234f9483b8baab39&oe=5A5098C5

09-08-2017, 12:53 AM
...No shims are required at the rear whatsoever.
...The shims probably could be ANY washer, the ones on my car have a small portion of the circle which is flat. Although it does not seem this is required as there is nothing to interfere with these particular washers... (Aaron, I deleted that huge picture because it was wider than 800 pixels.)

...Proper procedure is to bolt the lower 'A' arm to the #2 crossmember first (that's the rear bolt) with no shims. Then, shim the front bolt until all the extra space is gone...

...You said to tighten the rear bolt/bushing and then shim the front... I did not intend to indicate that any of the bolts be tightened until the car is sitting in the normal stance. My instruction is to 'bolt', and I can see where you might construe this to mean 'tighten', but NO, not yet.

The 'A' arms do not pivot on these bolts. When the bolts are tight, the teeth in the inner bushing dig in to ensure no motion will happen on the bolt. All motion pivots about the urethane, which is why these arms need to be centered before tightening.

Here's my warning: If you tighten while the wheels hang, you will certainly hyper-twist and break the urethane on the first speed bump you go over. Then, new bushings will soon be in your car's future.

Some members swear that there are NO shims in their Squarebird's lower 'A' arm. (I find that to be very improbable.) Other members didn't see any until they started cleaning the front bolt areas. It seems the washers were rusted onto the crossmember, then they fell out when agitated.

The first shims Ford used were a large 1/16" thick square steel with a 7/8" hole. Later, Ford changed to using round shims (or washers). There is nothing fancy or technical about these shims. Aaron is right, any mild steel will work even if you have to make them.

How much can you force more shims in? Remember, they 'stack' with the urethane bushing so, a little tight or loose will be compensated for by the urethane in the bushing.

Nyles wants to know if adding shims to the lower rear bolt will modify the alignment. It sure will. Think of it; by moving the lower 'A' arm forward, that moves the lower ball joint forward. Normally, we shim just the upper 'A' arm to adjust both caster and camber.

It's a combination of these shims because they too can have different thickness on each side of the same upper 'A' arm.

Aaron's Brakes: How did you adjust the output shaft on your booster? - Dave

09-08-2017, 03:57 PM
(Aaron, I deleted that huge picture because it was wider than 800 pixels.)

Aaron's Brakes: How did you adjust the output shaft on your booster? - Dave

No problem Dave I noticed my error and tried to fix it at about the same time as you removing it, its no problem at all.

And as far as my brakes, I don't HAVE a booster! I really think I need one, but i don't have the bracket! Yes i seen some making their own bracket but im not convinced of my ability to do so. So my 59 has DRUM brakes at all 4 corners, (originals not granada, etc) and although it says Power Brakes on the pedal, and it HAS the small bellows type booster, it DOES NOT have a firewall booster and it really in my opinion needs one. I'm using a master cylinder for a manual drum brake car. It works although I seem to only be getting front brake action. My rears have not really started to show that pressure that the fronts do and it takes "priming" the pedal once to get ANY type of stopping power on the 2nd application of the brake pedal. It's been this way for years and i really thought the master cylinder would fix this, but until i get it bled further I really can't say what is going on.

I am in the market for anybody's used booster bracket although I know how rare and unobtainable these can be. I'm going to go take some more pictures this evening and post so you can better see what im doing.

Would seperating the rear brake circuit from the "pressure switch" help? I have it that way on my 65 mustang drum brake car and it stops great. Worlds difference to the bird.

09-15-2017, 09:04 AM
This thread has gotten so off subject that I do not know how I can clean it up. I certainly have not helped by responding to the tranny and brake questions. Unless I or Dave can figure out how to take out posts regarding tranny or other subjects. Later in the day, I will see what I can do to clean this up, if anything. PLEASE, remember to keep the postings on the subject at hand, which started out to be Lower Control Arm Shims....

09-15-2017, 10:47 AM
I am in the process of taking out ALL the tranny and the brake posts and starting new threads on those subjects. It is time consuming to do so, but here is the Lower Control Shim question thread, minus all the other stuff... PLEASE... keep your threads on subject...

09-15-2017, 01:27 PM
sorry Ray i didn't want to clog up the forum making a bunch of seperate posts but that would make it easier to find this information in the future. I won't let it happen again.

09-15-2017, 01:57 PM
One of the good things about keeping a thread on subject is that often times ya'll come up with great Tech Tips with good pix on how to fix a certain problem. Often some of you create those Tech Tips into a format that I use to create information to add to the Technical Resource Library (TRL). If they stay on subject, then it is much easier to do and I do not have to clean it up. When you look at the TRL you will often see this Tech Tip or that one, created by so and so on our Forum. It certainly helps to keep a thread on subject so that it does not get clobbered up with other subjects. It is better to start a new thread on a new subject. I just regret it that in the middle of fixing up the section in that Shim thread that talked about brakes and combo valves, I was distracted and accidentally deleted the original thread that I had as a backup...