The Alignment Thread

[Harley818]

Hi Hindsight,
I just completed my alignment, with the same goals as you post starting out. (although now I am wondering if I should have done 5 degrees of caster).
I wrote up a thread on the "Alignment process for the 818S" under the suspension threads. Could you take a look and see if I missed anything. Hoping to generate a process with one place for all the info.

Second question. I used 15.75 in for lateral link length. Mine measured 16 1/8 (but off a wagon). I am using the aluminum LCA's up front, and wanted to use sedan settings as I have adjustable lateral links in back. Do you know what the right length for sedans is ?
Thanks, your alignment info really helped me. Thanks for posting.

[CU9DZ]

I have not dealt with the bump steer problem yet. Just got the generic version of adjustable tie rod ends and rod to lower the connection point in mail. So it looks like there are multiple movements of the back of the lower control arm that can be done.
1. move the S shaped hurricane bracket to outside holes on frame.
2. just unbolt the bracket and put the flat side down, curved side up moving the bracket 180 degrees.
3. unbolt the black piece that attaches to aluminum control arm and spin that 180 degrees.
Some of these options might move the center line of rear bushing too far out/in and cause something to bind up.
Did anybody measure what each option did?
Dave

[Hindsight]

Harley, your write-up looked pretty good. The only thing I will say is that after buying and using a bump-steer gauge to check my bump steer, I found that even with the rear links parallel, I still had some bump out. You want zero bump, or some bump IN, but never out. Theoretically, if the rear links are exactly parallel, you are probably very close, but to play it safe, I would actually adjust them so the rear link is lower than the front link.... not much.... a tiny amount. This guarantees you'll have some bump-in which is safer than bump out. If you have a bump-steer gauge, use that instead.

I'm not sure about your caster method. Theoretically it could work but when I tried that method, I got a different number vs the method that an alignment shop would use so I went with the method where you check camber with the wheel out 15 degrees, zero out the digital gauge, then turn the wheel back to 0 then 15 degrees the other way and check camber again. The number you see is the true camber. It's a pain to do if you don't have turn plates but with some cardboard, tape, protractor, and sharpie, you can make it happen. I've done it twice now.

I also noted some slight differences from left front to right front. I attributed it to drift in the frame caused during welding by FFR.

Your string alignment procedure looked good. Very important that the strings are exactly the same width front to rear. You used angle, I used conduit. One thing about string alignment is that the alignment specs are supposed to be taken from the outside of the tire, where the tread is, in the center. If you take it from the rim, you are going to end up with more actual toe-in than you are seeing on your measure (the further out you go, the more you get). I did the math (triangle basically) and found that on 235/40/17, measuring from the rim gets you 1/3 less of the actual toe. Meaning, if you measure 1" of toe at the rim, it would be 1.33" at the tire (using large number to make example more clear). Also, the order of operations should be camber, caster, toe, bump. If you do bump, you may want to re-check toe afterwards. Cant remember if you specified that in your write-up or not.

Sorry, can't answer your trailing arm length question. I put my OEM ones on the bunch and marked center to center, measured it, then duplicated it on my aftermarket arms. I MIGHT have listed the length in my build thread but can't remember. Might just post a new thread asking for someone who still has their rear trailing arms off the car to measure them for you.

CU9DZ - Bottom line is that yes, all those mods put extra pressure on the rear control arm bearings. They won't bind up though. You can sometimes find spherical replacement bearings online but if you do, they are extremely expensive ($400+). Many of us have been running with the caster mods without issue.

[Harley818]

Hindsight,

Good to know about the correct order, but with my double check method, I think I took care of that and didn't see any measurable variation.
Next time, I'll do the toe in with an angle across the width of the tire so i can measure it at the tread distance. good point.

Also, I'll try the caster method you mention. I have my own slip plates, two pieces of plastic with grease, so I could try this, if I can determine how to get 15 degrees each way with any degree of accuracy.

Thanks for the review and comments. I think I'll copy and post yours at the bottom of my process so others can see your comments in the same location.

[Canadian818]

I used a Longacre Caster/Camber tool, and highly recommend one. There instructions list measuring at 20 degrees, and they've machined the outside part of their gauge to 20* on each corner. All that's required is to line up said edge to your alignment string, zero out the gauge, then turn the wheel until the other edge of the gauge lines up, then look at your caster bubble. No need for drawing lines, protractors, or fancy turn plates.

[CU9DZ]

OK. I'm confused.
The hurricane bracket on the back of the lower control arm has a straight wing and a curved wing. The curved wing is about 9 mm longer the straight one. Currently my bracket has the shorter straight wing facing out. If I rotate the bracket 180 degrees the longer wing would be facing out and would push the pivot point inward not outward. the idea is to move that pivot out in order to push the lower ball joint forward.
Also once the splash panels are riveted in place the whole back end of the control arm is very difficult to get to. The only easy thing is to shorten the back part of the upper A arm.
Dave

[flynntuna]

I used a Longacre Caster/Camber tool, and highly recommend one. There instructions list measuring at 20 degrees, and they've machined the outside part of their gauge to 20* on each corner. All that's required is to line up said edge to your alignment string, zero out the gauge, then turn the wheel until the other edge of the gauge lines up, then look at your caster bubble. No need for drawing lines, protractors, or fancy turn plates.

Which tool did you use? http://www.longacreracing.com/produc...lignment+Tools

[Canadian818]

Which tool did you use? http://www.longacreracing.com/produc...lignment+Tools

Part: #78260