Alignment suggestions

[hyper7]

Well I FINALLY got around to string aligning my 7 this weekend, and honestly it was pretty easy to do myself.

 

Hardest parts were getting the string parallel and keeping the pole on top of the 4x4s I ended up using at the front to get it through the middle of the wheel.

 

I was only off about 5mm of toe overall, but my steering wheel was 45° off, which I knew just from driving.

 

I found it easiest to line one wheel up at the correct measurement, then just adjust the other side in, then took the steering wheel off to square it.  Not sure if that'll cause me issues in the long run, but I couldn't really come up with what it could do (aside from maybe limiting total turning radius in one direction?)

 

Ready to drive the couple hundred miles to LOG 44 in Pittsburgh now!

Edited August 18, 2025 by hyper7

[CarlB]

The issue with measuring total toe with toe plates or adjusting the toe on one side of the car is bump steer. When the wheels go up and down vertically the toe can change. This primarily affects how the car feels to the driver. It adds some unpredictable handling and driver confidence. If you draw a line between the upper and lower control arms on the inner and outer pivots, the tie rod joints should fall on those lines. That way the wheel can move up and down without inducing extra steering. Correcting this on a 7 is not hard. The way I do it is at where the steering shaft goes into the rack. Turn the wheel all the way in one direction and make a mark vertically on the shaft and housing. Turn it the other direction and make a similar mark on the rack. The wheel will turn more than one revolution. back out the one complete turn and the center is halfway between the two marks. Create a mark there. Use that mark to center the steering rack. Do a string alignment to set toe, or toe plates and make sure the tie rods are the same length.       

[hyper7]

Thanks, I'll do that

[wdb]

@CarlB thanks for speaking up regarding centering the steering rack and equalizing the tie rods. My car had a misaligned steering wheel as well. I started by centering the wheel/rack, which made it quite clear that one of the tie rods was considerably off from the other. I got them as close as possible via counting threads. Then I moved on to the finer adjustments. 

 

I think it is important to note that a great many 7's were assembled by amateurs! I shouldn't be surprised by how far off mine was.  

[hyper7]

Well I'm definitely an amateur lol

[hyper7]

So have it sitting on my lift right now,16 1/8 on the left and 17 1/4 on the right.  Yeah seems like I'm pretty far off center.  Would have been nice to have a detail about this in the build manual. 

 

But the steering rack itself isn't centered on the chassis...so not sure how much this matters...but I'll keep going down this rabbit hole

Edited August 19, 2025 by hyper7

[hyper7]

Measuring exposed threads on the ends, I'm at about 17mm left, 17mm right

[hyper7]

Turning the wheel fully to both sides gives me the same mark on the steering column, within a couple mm at least. So....am I good then? Clearly I've never done an alignment myself before.

[CarlB]

On my car there is a small hole in the crossmember just under the steering rack. That is the center of the car. I spent a week measuring the pickup points on my car to see if it was strait. I am confident that Arch used that in their jigs when they made the chassis. I also measured to the blocks that hold the steering rack, and they are equal distance from the hole in the chassis. At one point I played with stock cars. They are always getting driven into walls, so you spend a lot of time learning to measure stuff. 

[CarlB]

35 minutes ago, hyper7 said:

Turning the wheel fully to both sides gives me the same mark on the steering column, within a couple mm at least. So....am I good then? Clearly I've never done an alignment myself before.

On my car with a quick steering rack the wheel turns about one and one half turns in each direction. Maybe a little more, it has been a while since I did it. Are you going lock to lock on turning the wheel?    

[hyper7]

Yes, lock to lock is one full turn in each direction.

[hyper7]

Ok so I'm thinking this through.

 

Steering wheel currently straight turns one full turn to each side and ends up straight (maybe a degree or two more to the left).

 

Parallel strings give me a reading of +1mm on each side, for a total of +2mm (shooting for spec of +2.5mm)

 

Camber reads -2.4° on both sides. Probably more than I want (found a spec suggesting -1.5°) but I don't think 2.4 is super excessive. 

 

Therefore the wheels are parallel to each other and the steering wheel is square to itself, which means I'm good.

 

Right?

 

[IamScotticus]

5 hours ago, CarlB said:

make sure the tie rods are the same length. 

Based on what reference point?  The chassis center line?

Edited August 19, 2025 by IamScotticus

[CarlB]

2 hours ago, IamScotticus said:

Based on what reference point?  The chassis center line?

What you are doing measuring the threads works. Someone said the rack wasn’t centered. I should have quoted that statement. This misunderstanding probably has more to do with the meaning of rack. The rack meaning the housing is centered. I measure the tie rod length from the blocks that hold the rack down.

[hyper7]

Yeah the silver part of the rack is offset, so the left and right tie rods themselves are different length. Measuring to the mounting block is the same on both side. Ok, so I'm confident that I'm good now 😀 

 

Also this exercise helped me realize I had a slight coolant leak at the coupler above the rack, so that's good I guess

[CarlB]

We have, or had, a confusion about names. The steering rack assembly is made up of a housing, a round gear, and a rack gear. There are bearings and other things, but the basic function is controlled by those components. You turn the steering wheel and that turns the round gear. The round gear is connected to a long flat gear called a rack gear. All of this is inside a housing that holds it all together in one place. On the ends of the rack gear are joints that allow the tie rods to move up and down and side to side, but not in and out. What is centered are the joints on the end of the rack gear. When you project a line vertically through the center of the lower inner control arm bushing to the center of the inner upper control arm bushing the inner tie rod joint (joint on the end of the rack gear) should be centered on the projected line. The other part of eliminating bump steer is the outer joints, and the center of the tie rod end need to have the same geometry. If one tie rod is longer than the other the joints are not on the imaginary line through the suspension joints. When you hear racers talking about bump steering their cars, they are improving the accuracy of the components being in the correct alignment to each other. There are always tolerances, and the racers are trying to improve the tolerances. On regular street cars the manufacturers often design in bump steer to make the cars understeer. When you are trying to drive a car quickly you want to judge the tire slipping, and you are looking at very small amounts of slip. If the steering angle is changing because of bump steer the car isn't as predictable.