Manual steering, supposed to steer side to side on accel?

[Shawn MacAnanny]

I must admit asside from a dump truck i had ive never had anything with manual steering. I converted to a manual box when i did my ls1 swap because i wanted to save a couple pounds and not have to worry about hooking up the power steering pump and all. Well ive finally taken the car on the road to 'test' it out and it seems like the steering is just kind of 'loose'. Now i am used to driving my 94 LT1 camaro which is lowered 2" and has a full after market suspension setup so i know it's not going to be anything like that.

When i acclerate the front end starts to rise (wheels not off of the ground yet) and seems to kind of veer left of right. Now i am running Centerline telstar 4" wide wheels with whatever size tires is on them. (26x4.5) i think so i know they are going to be easier to steer. I also did replace a tie rod which i'm sure threw the alignment off but before the swap the car did drive and steer better. It did have a Pontiac 400/400 in it. The car is origionally an OHC 6 sprint car which i believe has the origional suspension in it as my ride height looks normal rather than slammed as it did before.

Any ideas? I shoudl probably go get it aligned first right? Hubs are fine, brakes are fine, wheels are tight, suspension is grease, bushings are tight.

The rear suspension is a 74 nova rear end, 4.56 posi, i have lift shackels which are lifted to the 3rd and last hole (to clear 30" tires which are coming). I have lakewood traction bars, a competition engineering innner shock relocation bar, summit adjustable shocks (set on softest setting in rear) and the leaf springs are multileaf springs, 4 springs up front, 3 in the rear (half springs i guess), 15x8 Centerline Telstar wheels with 26x10 MT ET drags @ 20psi. the front suspension is bone stock from an OHC 6 from what i can tell.

[Ripper]

Sounds to me like you have very little caster?

[Shawn MacAnanny]

And how would i fix that? They would adjust with a normal alignment, correct?

[silver69camaro]

Does it steer the opposite direction on braking?

Possibly the housing is steering under acceleration?

[Marcus SC&C]

Factory caster for that car is very minimal by modern standards,something like 0* to +1* (your late model runs +7*!). Raising the rear end of the car reduces + caster even more because you`re tilting the car and the spindle forward. At that point you probably have - caster which tends to make the car directionally unstable. When you launch the car the front end comes up and the suspension droops which causes 2 things to happen. It looses more + caster (or gains - caster in this case) due to the front upper arms antidive angle AND the factory bumpsteer causes the front end to toe in. If you`re topping the suspension out total toe in could easily be 1/2". A little toe in is good for stability but too much can still cause instability especially if only one tire (usually RF) has much contact pressure with the ground.The light aluminum LS motor probably already raised the ride height and compromised your alignment settings. The combination of - caster and toe change can make any car loose and twitchy. The manual steering`s got nothing to do with it. Check your static alignment. I`ll bet you can use a lot more + caster. The factory parts will only allow a small amount of caster adjustment but you should be able to make it better than it is now. To eliminate the problem altogether correct the geometry and put a set of aftermarket arms on that either have more + caster built in or are adj. like ours to allow a much wider range of adjustment. Although this sounds more like a `70s drag car theme there`s no reason why this Firebird couldn`t handle and drive just as well as your 4th Gen with the right parts and suspension tune if you decide to go ProTouring. Mark SC&C

[JEFFTATE]

Like Marcus said.
Check the static alignment.
Too much toe OUT will make it wander too.

[Shawn MacAnanny]

Yeah i would describe it exactly as wandering. Now i have never really aligned a car so where should i start? Any good write ups? Using the tools i have i was thinking running a string line across the rear tires up to the front and measuring in to make sure they are both parrallel with the string line. As for caster how could i get that corrected? I was planning on cutting a half coil or so off of the spring.

[David Pozzi]

Marcus has an excellent post, all good info.

If I could add anything I'd say that common issues with early F bodies are slipping or movement of the rear axle on the springs, usually due to the rubber or poly pads. This should show up with the car pulling to one side on launch. My 67 Camaro had the axle slip forward on the left side, it caused the car to pull left on launch.

Bumpsteer or loose components in the front suspension.
Shot subframe to unbody mounts and bolts.

Your narrow tires will ease steering but you lose a LOT of directional control. I once borrowed some skinny front tires for a couple of days and it was scary how badly my car drove on the street!

David

[Shawn MacAnanny]

Here's a couple pics i just took. This is pretty much the only first gen bird ive ever seen in person (not any in Delaware that i have seen) so i am really not sure what 'stance' it should have. Those are 26s on the back and front. I plan on running 28s or 30s in the rear.

[Norm Peterson]

Those lift shackles aren't doing your straightline stability any favors either, and if the rear end can wander around under power it'll stilll push you, just not always straight ahead. I'm sure that the roll steer is different and there is certainly less-accurate lateral location for the axle. A friend of mine installed those things on a '67 Mustang "back in the day" - worst thing he could have done even with only a mild 289 - the car wanted to go every which way but straight (I drove it that way, just once).

If you must keep the long shackles, consider a panhard bar installed about at axle height (which will involve a little more chassis bracket structure due to the height involved).


Norm

[Shawn MacAnanny]

Well when i made my mini tubs It took a couple inches clearence out of my wheels wells and i left them lifted up to make sure my tires will clear during launch. I think i will only be running 28" tires so it should be fine to lower the shackles back down.

[Shawn MacAnanny]

Here are a couple pics of the rear suspension

https://www.pro-touring.com/forum/attachment.php?attachmentid=25105&d=1217692696

https://www.pro-touring.com/forum/attachment.php?attachmentid=25104&d=1217691667

[Shawn MacAnanny]

Today i decided to do an at home alignment for toe. I measured from grease fitting to grease fitting on the tie rods and right of the bat the tie rods were about 5/8" off from each other. Then i made a centerline down the tire and measured from line to line at the front. The front was like 59 7/8"" and the rear was 62 3/4" so it was WAY toed in. I got both tie rods even and kept them even the whole way.

I ended up with both tie rod zerks being something like 15 11/16" apart and the front i left toed in 1/8" on each side (1/4" shorter in the front). It drive about ten thousand times better. No vibrations, no crazy steering i can even let go of the wheel and it steers perfectly straight! It did make it noticably harder to steer at low speeds but i mean its not difficult at all to steer. I used this awesome article i found which really helped alot. I dont want to adjust my caster or camber as it see the shims in there already and ill just let the shop align them when i take it there. I have no problems driving the way it is now though.

http://www.carcraft.com/howto/48938/index.html

[6'9"Witha69]

If I could add anything I'd say that common issues with early F bodies are slipping or movement of the rear axle on the springs, usually due to the rubber or poly pads. This should show up with the car pulling to one side on launch. My 67 Camaro had the axle slip forward on the left side, it caused the car to pull left on launch.Before even openng the thread this was my first thought.

[Shawn MacAnanny]

I just put the new rear in, and was very careful to line up the two tabs and such. Also i used two u bolts rather than the t bolts or whatever they are called and they were tightened all the way through the traction bars with a 3 ft breaker bar. I tightened it down until i thought the axel housing might get bent. I used two spring pads for each as i removed a half leaf as well.