guitarman376

So in the future I will be adding positive caster to get better return to center in my steering. Meanwhile, placing the front wheels further back in the wheel well wouldn't hurt. To me shimming the front control arm bolts more would work well...

My main question is if doing this decreases camber. Yes camber. I have about -.6 degrees right now and wouldn't mind a little less.

Also, all control arm bolts are shimmed right now... I think alignment shop said 1/4 or 1/2" shims. I'll have to find that printout. This was necessary because I dropped the upper control arms 1.5" instead of less, creating a lot of negative camber but damn she handles amazing.

Is it bad/unsafe to shim upper control arms this much? Like I said all bolts are already shimmed a good bit. I'm running opr track roller arms, with the flat mounting surface. Do the front outermost shims need to be angled? Are they soft enough to not move around? Am I over thinking it?

67mustang302

You shouldn't need much shim, they're typically used in 1/16" sizes. Changing the caster will change everything.

guitarman376

@67: Well, my lower control arm with eccentric eliminator kit is mounted as much inboard as possible on both sides... And for alignment shop to properly align the car the shimming was necessary, negative camber was crazy beforehand. Again I think this is because of the lower control arms getting dropped 1.5" instead of 1". If I had known this I probably would have done like a 1 1/4" or 1 1/8" drop.
The other thing I wish I had known was how much caster for the alignment. To anyone curious with your upcoming alignment and stock style manual steering with roller idler arm, I ran +2.5 degrees caster and have awful return to center. I am working towards getting pretty much as much caster as I can, at least 4 degrees maybe more. I will see for myself how much effort this adds, the only reason I chose this figure was people speaking of the steering effort. In the future I will have a borgeson setup and then it won't matter.

guitarman376

I still haven't found the alignment printout to check shim sizes, but it was quite a bit if I remember correctly, and my primary concern is if I need to grind or angle the most outboard front shims (to get more caster+locate wheel in well) or if it isn't good to shim something past a point.

Starfury

Uh, 1.5" is too much drop. At the upper limit of suspension travel, that's enough to bind (and maybe break) the upper ball joint. Aftermarket arms, like those from Global West, have this factored in by changing the mounting angle of the ball joint.

Also, more caster moves the tires forward in the wheel well, not backward. With 2.5* caster, your return to center should be great. How's the toe? Also, is everything in the steering nice and tight? If the toe is set at 0* (what a lot of the Hunter alignment machines recommend for these cars), or even if it's set properly at -1/8" but without any pressure holding the front of the wheels apart (like it's being driven down the road), you'll have crappy return-to-center.

I run +2.5* caster, -0.4* camber, and ~1/8" toe-in. Return-to-center is fine, and the car is very stable at freeway speeds. Of course, I aligned the car myself, so I didn't have to rely on a shop to do it the way I wanted it.

67mustang302

Adding caster will actually move the wheel back in the well if it's done via shimming. The shims tilt the a-arm backwards into the wheel well. Using strut rods moves the wheel forward.

Starfury

Ah...doh.

guitarman376

starfury that is why i purchased opr roller track upper arms, allows 1.5" control arm drop

My alignment settings are -.6camber +2.5caster and I told shop 1/8" toe in but their machine measured in degrees so they did it that way. Like I said my return to center is pretty awful, and I caught the shop aligning the car without test driving it, so maybe their measured numbers were actually off. I am 99% certain however that caster is the solution, John at OPR told me what they run on their cars which is where I got my new desired number of at least 4 degrees.

I am strongly considering buying my own tools for alignment, however not having a flat enough space to do an alignment is holding me back. I honestly don't trust any shop ever, and I had a bad experience during this alignment process. Since I did pay $200 for a complete alignment, I wish I had known what caster the car would like beforehand.

Getting back on track I was wondering if there is a maximum number or thickness of shims to use, and also if the outer shims for the front bolts need to be angled to account for front having more shims.

I plan on adding equal thickness shims to front of control arms, therefore increasing caster, and then button everything up and take it somewhere for another alignment. There they can use the adjustable strut rods to dial caster in.

Starfury

Holy crap, $200? I don't know any shop out here that charges that much. Usually it's around $65-100. It's not like your car should be any different. Chevy S10's use the same shimmed UCA adjustments and don't get charged any more.

guitarman376

Needless to say it's difficult to find a good shop of any kind in my parts. Does anyone has answers to my thread questions?