1960 Impala Unisteer System

[Peter Birmingham]

On my 1960 Impala I added a Unisteer rack & pinion steering system. I also installed 2" drop spindles, disc brakes and coil over shocks. When we took it to the alignment shop the best they could do was -1 degree castor, Unisteer says +2 degrees. I installed tubular upper control arms with up to a built in +4 degrees of castor, then had the front aligned. Now when I drive it it's kind of twitchy if you know what I mean. When installing the Unisteer we removed the front sway bar because of interferences, would that make a big difference? Any suggestions or comments!

 

[1958 delivery]

Sway bar only reduces body lean, nothing to do with your problem. What brand tubular arms? Which spindles? I have not been impressed with any R&P conversion

 

[409 lever]

any chance the uppers were put on the wrong sides?and yes -1 degree will drive like a shopping cart.

 

[Jim Sullivan]

If you have a power assist rack, you may have too much pressure from the pump. If this is the case, I believe there is a different pressure regulator that is needed. I am sure someone here would be able to provide more information.

 

[HemiChallenger71]

What control arms and spindles?

What are your opinions on the rack? I was considering one for my build.

 

[Peter Birmingham]

I will try to explain this the best I can. The 2" drop spindles came in a disc brake conversion kit from Ecklers, the rack & pinion came from Unisteer and the coil over springs came from Viking. We installed all the parts and had it aligned. The best they could do on the caster was -1 degrees, Unisteer suggested +2 degrees. We installed new tubular upper control arms from Performance OnLine.com Item TCA-U5864 that were designed with an extra +4 degrees of adjustment. This seemed to fix our caster problem but the car still did drive good. We called Unisteer and it seemed we had a Bump-Steer problem, the car would kind of wonder off to the side without turning the steering wheel. It seem the tie rod was at an angle and it need to be parallel to the control arm. They suggested using a part from the Speedway catalog, an inner tie rod adapter bolt which of course comes with SAE thread. The Unisteer tie rods are metric so we are sending them back and Unisteer is going to replace them with SAE ones. This is where I sit now, the parts are suppost to be here this week and then we can install and adjust them. Stay tuned, I will let you know how they work after they are installed. The jury is still out on whether going to the rack & pinion was a good idea, will find out after I drive it a while.

 

[303Radar]

Since I may run into a similar problem, can you post a picture showing the angle on the tie rods? Here is a link to the thread with my future potential problem:
http://www.348-409.com/forum/threads/spindle-control-arm-problem.27473/

I was thinking of using a Flaming River R&P kit.

 

[HemiChallenger71]

Oh so your thinking it should have +3* caster now but it feels twitchy when driving. The caster will affect toe, it might be toed in(my guess) or out to much now. Remember R&P will have a lot more steering "feel" and the slightest inputs will affect steering. R&P usually will "follow" road surfaces especially with wider tires with less sidewall.

 

[Peter Birmingham]

I did not say we have +3 degrees camber, we have +2 degrees and had it aligned after the caster was set, The problem I am having is the Bump-Steer because of the angle of the tie rods which should be fixed with the new parts. I hope to post a picture of the tie rod tomorrow.

 

[409 lever]

I did a unisteer conversion on a 69 firebird two weeks ago and the project was a train wreck.after a bunch of internet searching these kits are not very well engineered,many upset customers,they want no part of retuning anything after it has been installed???how can I tell it does not work unless I install it..if I could do it over I would have just put a stock style manual box in the car.very costly mistake for myself and my customer.

 

[HemiChallenger71]

Thanks for the info 409lever.

Caster and camber are two different things peter. Clarify which your talking about.

If you have +2* camber thats a big no no!

 

[Peter Birmingham]

Sorry, I had a brain fart, I meant to say caster. No problem aligning the camber and toe.

 

[Peter Birmingham]

I have attached a picture of the tie rod, as you can see the tie rod is sloping up, it should be parallel to the lower control arm. Using the inner tie rod adapter bolt from Speedway should bring it down to parallel. I will let you know how it drives after we make the fixes.

 

[303Radar]

That isn't tilted up very much. I'm surprised that angle makes that much difference.
Definitely interested in how the fix works out.

 

[HemiChallenger71]

Man that rack hangs out in space... Thanks for helping me make up my mind about a rack and pinion!

As little as tie rods angle up, it will help to get them level. The spacers should help a lot. Probably will have to re set toe, at least check it.

 

[jim_ss409]

I think it's safe to say that a well engineered rack and pinion steering is superior to a regular steering box style setup,,, BUT the geometry has to be right.
The inner pivot point of the tie rod ends have to be in the right place in order to avoid bump steer. I don't know anything about the Unisteer system but I have seen setups that are just plane wrong.
I'm sure there's good info available in the internet, but as usual it might be hard to find.

I think Peter is right in thinking that he needs more positive caster. I think it would be nice to have at least +2 degrees but it wouldn't hurt to have even more to give the steering a really planted feel at higher speeds.
If I remember right a C4 Corvette suspension calls for +6 or +7 degrees.

 

[303Radar]

Which spindle are you using? It looks similar to the one '58 Delivery uses. If it is similar, there should be a lower mounting point for your steering arms than what is used. Assuming there is room of course.

 

[Peter Birmingham]

Here are a few pictures of the rack & pinion in the car. It install quite easily with 4 bolts hole already in the frame. We were concerned about the rigidity of the unit so we put a camera on it and took it for a ride, steady as a rock! Still waiting for one part.

 

[Peter Birmingham]

I cannot tell you exactly what spindle I am using, it was included in a kit for the disc brakes by Ecklers. See attached picture.

 

[HemiChallenger71]

You can see right in this pic. The steering linkage should be in the bottom holes on the spindles: