I've been having a problem with hard steering on my 69 Z28. I've known the steering box had problems for the last 20 years and I finally got around to replacing it, without much reduction in steering effort. It's possible I just don;t remember how hard the steering is supposed to be. My question is, for those of you with manual steering, how many turns of the steering wheel do you get, lock-to-lock? I have two, and that seems excessively fast.

 

There are 3 replacement manual steering boxes available; the "quick ratio" 4 turns lock to lock, a 5 turn and a 6 turn. If you're meaning to say that yours is 2 turns from straight on to full lock in one direction, that would be right for the quick ratio. But if you're saying it's 2 turns from a full left to full right turn, then you must have something restricting full movement of your steering components. What is your turning radius like, does it take a 6-lane highway to pull a u-turn?
If I force mine (manual box) in both directions, I have 4.25 turns lock to lock. Steering mine isn't hard, unless I had to parallel park, which I never do anyway. And with that, I have a smaller diameter aftermarket steering wheel.

 

The steering box was replaced 35 years ago when the original one broke. I know it came off a 69 Camaro, but that's all. The usual parts have been replaced - idler arm, tie rods, center link, ball joints, etc. The steering arms are original and the casting numbers correspond to Z/28 fast ratio length arms. The Pitman arm is the long 5.8 arm for quick ratio steering. The suspension turns completely from one side to the other until it hits the stops. Turning radius is normal.

The steering box had some problems when the car was restored in 1994, and I had always attributed the hard steering to a bad box. I replaced it this week with a new 16:1 box. The old box was three full turns from side to side on the bench. In the car it's two. The new box is four full turns side to side on the bench. Hooked to the pitman arm it's two - from full left to full right, two turns. Or, from center, one turn to full lock either way.

 

I would say the box has a small numerical gear ratio.
The smaller the ratio, the harder to turn - same principle as rear axle ratio in moving Camaro forward.
Also, rolling friction is easier turning - as the Camaro rolls, steering gets easier.
Bigger steering wheel equals less effort - longer lever.

Since the Pitman is 5.8 inches, idler arm should be of the same length for retaining Ackerman steering, otherwise the outside tire will scuff in a turn.

 

The box is advertised as 16:1, which would be four turns. The worm gear will actually travel four turns if I disconnect the pitman arm. Hooked to the car it moves two turns, which is half the distance the box alone will turn. The old steering box was three turns by itself, which would be 12:1. In the car it's two.

 

You could give the shorter (5.25") pitman arm a shot. That will increase your number of turns, and lessen the turning force at the steering wheel.

 

I tried the shorter arm. No difference. Maybe an eighth of a turn more. If I was getting two or three turns with the original 12:1 box and four to four and a half turns with this one and the steering effort was less but still too high, I'd just figure I'd need the 24:1 box. The problem is that even with the 12:1 box I run out of steering travel well before I run out of turns with the box, even with the quickest one.