Steering Wheel Won't self- center

[another69]

My car goes straight when I take my hands of the wheel, and the steering feels really good, it just doesn't self center the steering wheel after you loosen your grip after a turn. Not a huge deal, but I thought maybe not enough caster, so I checked my alignment and here is what I have:

Camber: -7/8 degree both sides
Caster: +5.5 degrees both sides
Toe: 1/8" total toe in

I would think it should center, what am I missing?

[dontlifttoshift]

Make sure there is no bind in the linkage, column, hub adapter to colum, etc.

Make sure the steering box is not adjusted too tight.

List all of your components, from the steering wheel out to the control arms.

[another69]

That's something that didn't even cross my mind. I'll put it back in the air & try the steering with no weight on the wheels. On the turnplates with weight on it but the motor off it felt like it normally does, which I guess is a bit tight.

Steering wheel: Momo replacement
Column: Rebuilt stock GM
Unisteer power rack
Column to rack: DD shaft with (3) u-joints. one of them is a vibration reducing joint
Outer tie rods & steering arms: Unisteer
LCA: Modified stock with Delrin bushings
UCA: SC&C (SPC) with tall upper ball joint

[dontlifttoshift]

With the car on the ground, loosen the set screws or pinch bolts (assuming unisteer joints) and turn the wheels lock to lock then back to center. Retighten pinch bolts and test drive. I assume camaro, rubber subframe mounts? If the linkage is tightened on a lift, when you set the car down, now the linkage is too long and that puts a load through the ujoint that will make them tight. Yes it really moves that much and it really doesn't take a lot to bind those itty bitty needle bearings.

Make sure none of the u joints are binding on themselves. Make sure you don't have excess steering shaft sticking through the ujoint and bottoming on the trunnion. With DD shaft, you can't be out of phase with the joints but that will cause this issue too.

Is there clearance between the hub adapter and the bell on the column? That is the most common issue I see.

[another69]

I'm doing the work on a 4 post lift, so there is a load on the wheels the whole time. I used my bridge jack to lift the wheels and turned lock to lock and it felt tight but smooth the whole time. I have solid DSE mounts & subframe connectors, so no concern about the stock bushings. You bring up another good point about the ujoints though, I may have some kind of binding that I didn't originally realize.

What do you mean by the bell on the column?

[pitts64]

There's more leverage on the suspension when the car is on the ground supported by the tires only..

Too much toe in will cause return issues along with a vague on center feel... Might want to try toe out...

[David Pozzi]

Loosen the idler arm to the frame, then re-tighten.

[another69]

It's a rack, so no idler arm, but thanks. This weekend I'll try to loosen all of the ujoints, retighten, and see if it helps. When I originally put the rack in I had urethane subframe bushings, and now I have solid, so that may have something to do with it.

[TheJDMan]

When I first installed my DD steering shaft I had one u-joint that was binding ever so slightly but just enough that you could tell something was not quite right. I loosened all the u-joint set screws and turned the wheels lock to lock a few times then tightened it all back down and that cleared up the binding.

[another69]

Well, I have spent a ton of time on this. Bought new ujoints from Unisteer & their support bearing. Had it apart and back together 8 times I think. The feel is now better from 3 o'clock to 9 o'clock, but past that I can feel it bind. The steering now feels really inconsistent.

I am using 3 ujoints from the column to the rack and I did my best to measure their working angle. From the column to the rack I have 16deg, 25deg, and 34deg. Max working angle is listed at 38. I don't see how I can reduce the worst one from 34deg. I will try and post pics if that helps.

[Mike H]

Also what are the specs on your wheels? Too much backspace that puts you at a negative scrub will fight the wheels going straight.

[another69]

That's something I never considered - fronts are 17X8s with 4" backspacing. The Wilwood front brakes are 1/2" wider per side than stock.

[Sleeper68]

Do you have the U-joints phased at 45 degrees phase (I think that's the spec, would be a good idea to check the instructions)? If not, your linkage may bind.

I feel your pain, I also have the Unisteer R&P in my '68 Camaro and have been fighting all kinds of issues with it for awhile now (zero bumpsteer my @$$)...

Scrub radius can also cause self-aligning torque issues (what brings the tires back to center, caster effect) and our cars do have issues with scrub radius but 17x8 @ 4" backspace is not a very high positive offset so I doubt neg scrub radius is an issue. You have quite a bit of caster in the car and it should be able to overcome the scrub issue. What tires are you running? very sticky fronts can be notorious for this issue if scrub is too high, just go drive a new Z/28 on 305mm 80 treadwear Trofeo R's.

I also use the BBC linkage (3 joints) and it is very difficult to keep the angles small because of where the rack input is in relation to the column. One thing that may bee making it harder on you is the fact you're using a stock column. I have a Ididit column and it may be shorter. What do you use to adapt the column to the linkage? I saw you said something about a flex/vibration reducing link? How is that implemented? pictures may help expodite the process.

Hope this helps,

Ryan

[another69]

I got rid of the vibration reducing (borgeson) joint and now I'm running all unisteer u-joints. Their bolt-through-a-notch pinch bolts seem like a good design anyway. Originally 2 of the joints were not mis-phased, so I took it all apart & mis-phased them. Put it all back together and... NO change. I'm happy with the bumpsteer, it is very minimal on my car, and there is no steering play which is nice. It's just not consistent and I know that there is some sort of bind somewhere that is driving me nuts!

I'm using their support bracket which pretty much determines the angle of the last two joints (middle & rack). The joint on the column has a very minor angle.

I'll try and post some pics here. Nice to hear that you're an M.E. fighting similar problems!

[another69]

Here are some pics, BTW tires are Falken Azinas 615s

[Sleeper68]

One thing that may be causing you grief is the "longer" column you have due to the fact it is a stock unit and requires the adapter splined flange to use the Unisteer input u-joint. Because of this you have less line length in your linkage and thus more obtuse angles in the joints.

Is this self align issue isolated to low speeds? Or is this an issue at every speed. If so, does the self align issue improve as vehicle speed increases? The 615's you have will cause align issues in parking lots and such (I have the same tires). The wider the front wheels, the more scrub (essentially resistance to turning) and cause the exact issues you have described. What width and backspace of front wheels/tires do you have? a 245 section front on 200TW rubber will scrub in parking lots, 275+ is really a pain in the @$$.

Given you have noted there is no bind and no play in the steering when the front tires are unloaded, this leads me to believe you are experiencing a "tracking" issue directly related to scrub on very sticky front tires.

BTW, make sure you tighten the allen bolts in the linkage to torque spec as noted in the instructions (I believe 60 lb-ft). This is very important to make sure the misalignment angle is maintained (least chance of bind.).

~Ryan

[another69]

The bind seems to be in the u-joints farthest forward, which also have the most severe angle. The bind is there with the tires loaded or unloaded. The u-joint angle is pretty much determined by the (Unisteer) bracket, right? I can't really grasp how a shorter column can help the joints forward of the bracket - can you explain?

The self align issue is most noticeable after a turn. The steering wheel doesn't unwind when you loosen your grip. Front tires are 245/17 with a 3-1/2" or 4" backspace. I am running spacers to increase front track which may be hurting me some... but I really like the wheels as far out as I can without rubbing. I was about to pull the trigger on the AFX spindles and a "true" coilover conversion (I have QA1's version now), but now I'm thinking about a whole new aftermarket subframe now if that's what it will take to fix my steering.

U joints are all torqued. Too cold to drive now, but any day now I will give it another test drive.

[Sleeper68]

A longer effective column can cause more bind because you will have less line length in your linkage. Think of a hose that needs to make a 180* turn. A longer piece of hose will make the same turn in a larger radius (equals less severe angle in a 3 joint linkage) than a shorter piece of hose. Obviously we are not dealing with hose, but the general idea is the same. You are limited by three things: 1. the location of your steering input (steering column) 2. The location of the rack input 3. The location of the center support bearing.

Two limiting factors are movable, one more easily than the other. The center support bearing location be moved easily by making a new bracket. Moving it inboard and up will most likely be the best way to help the bind. Moving your steering column output is harder but achievable with a new aftermarket column. I would try different locations of the center support bearing (the heim joint) and see if bind is reduced. You can move it by threading the join inboard or outboard and also by only using one of the through-bolts that mount the bracket to the frame.

Hope this helps,

Ryan

[another69]

Thanks, but I give up. I hate to say it, but I'm throwing in the towel with this thing. Steering has too much assist at some points and then it gets inconsistent at times when it binds a bit. It actually felt better when it was always in bind with my old u- joints because at least it was consistent. The more I mess with the joints, the worse it gets. The crazy thing is that I have one of those (ugly) HD Ford Transit vans and the steering shaft on it makes about a 150 deg turn!! The steering on that damn van feels better than my car lately though, which is a real kick in the nuts. So along with an LS3 swap I'm going for a whole new subframe. I'm leaning towards AME, DSE, or the Speedtech Extreme. Whichever gives me the best steering feel and handling. I'm not looking forward to the cost, and really like to do things on my own, but I think it's fair to say that these guys do it better than I can.