Checked the casting numbers on my pitman arm. 3741383B. So the pitman arm is not the problem! Where to from here?

 

On your '74 Vett you should have two sets of tapered holes in your steering arms. The arms are extending rearward from the steering knuckle. The rearmost holes (longest arm) is for manual steering. The tie rods on a manual steering car can be moved to the forward holes (shortest arm) for a faster ratio.

With power steering, only the forward holes (shortest arm) are to be used. I am not sure of the actual problem but I believe that there is some type of interference if the tie rod from a power steering system is installed in the rearmost hole.

Jim

 

Jim, Do you have a photo or can you do me a drawing?

 

Manual steering tie rod being installed in steering arm at the slow ratio (longest arm) position.

Jim

 

I've had a look. The steering tie rods appear to be installed correctly (short arm position). The long arm holes are plugged with some sort of grommet that does not appear to have removed or replaced ever.

 

Finally got around to trying out your suggestion. With front end lifted, engine off, I had no problems turning the steering wheel. Can we now conclude that my problem is hydraulic not mechanical, and if so, what could the problem be?
I did learn one thing from this exercise: Pressure must build up in the system because p/s fluid squirted out of the top of the filler cap. Another 5 minute job that turned into a 2 hour saga (engine bay wash, car wash, garage floor wash).

 

Jim, your thoughts please: With front end lifted, engine off, I had no problems turning the steering wheel. Can we now conclude that my problem is hydraulic not mechanical, and if so, what could the problem be?

 

Since your problem is only in full left turn, the problem cannot be the pump. (The pump doesn't know which way you are turning.)

You never did mention if the problem just suddenly surfaced or not?

This leaves just a couple possibilities:

Still something mechanical that interferes near full left turn with the suspension in its normal down-the-road position. (I assume that when you raised the front end, engine off, the front wheels are hanging in full rebound position.)

Next there might be something wrong inside the control valve (such as left to right balance).

Something inside the assist ram with the rod fully extended.

The last steering component would be the steering gear itself.

One last thought. You mentioned that you replaced the flexible coupling assembly. In order to do that, you should have done one of two procedures:
1. You needed to unbolt the steering column and pull it back inside the driver compartment in order to disengage the steering shaft from the coupling assembly.
2. Or you had to remove the steering gear attaching bolts to the frame and tip the gear so that the coupling assembly could be disengaged from the gear input shaft.

In either case, you need to make sure that when you reinstalled everything, the steering column has to be aligned to that it points directly at the steering gear input shaft. You have to make sure that there is no binding when turning the steering wheel. Inspect the stop pins that are part of the flexible coupling. The pins should fit into slots in the flange that is part of the steering column shaft. The pins should not touch the column flange and there should be about 1/8 inch clearance (stop pins to flange slots) in all steering wheel positions.

Jim

 

Jim, Further to you suggestion: "Still something mechanical that interferes near full left turn with the suspension in its normal down-the-road position", I have now tried full left turn with the engine off and the car on the ground. Obviously, the steering was very heavy, but there was no sticking.

 

Ah - thanks for posting this; that was what I referred to in my post...but I couldn't fully recall