Interesting this pitman arm problem has come up a couple times in the last couple weeks. Anyway, maybe a posting from a private message to me might be of help to others.

Originally Posted by John 65
Hi Jim, maybe you can help me with this ps problem. The complete system is fairly new in my 68. A couple hundred miles at most. When I turn full lock to the left, as it gets near the max amount of steering wheel turn, the system grabs and locks the steering wheel there at full rotation to the left. Takes 2 hands to break it free and get it back to the right again. On the ground and with the tires in the air this happens. Nothing is hanging up, no kinks in any hoses, suspension is new also. Just started today. No leaks also. Its like at almost full left, the ps system grabs hard and snaps the steering wheel and holds it there. Thanks, John
--------------
John,
I think that you do not have a power steering pitman arm. The manual steering arm and the power steering arm are very similar to each other. However, there are subtle differences in the offset and bends in the arms.

The manual steering pitman arm has the numbers 3829452 forged or cast on the arm. It was used on 1963 through 1976 manual steering Corvettes.

The power steering pitman arm had the numbers 3741383 usually with an "A" or "B" suffix. It was used on 1963 through 1982 Corvettes with power steering. It was also used on all full size 1958 -62 passenger cars as well as 63 and 64 full size passenger cars with power steering.




----------------

Jim, Thank you ! You were absolutley correct. Somehow the manual 65 arm from years ago wound up on my 68 power unit. Swapped them out and problem solved. I really appreciate the help, I was about to swap the valve, glad I asked you 1st. Have a great day.
John

 

Jim,
Very informative! Thank you.

 

G'day,
I have a factory '74 coupe to which I fitted a Borgeson integral power steering box. I re-used the factory Pitman arm, presumably a "power" one, but I also replaced the control valve with a Drag Link Adapter. So far everything looks well and I have had no problems with the steering wheel wanting to go somewhere I did not want it to.

Jim, I am really appreciative of your huge input to this Forum since I have been on it and have learned a lot more than I already knew. I hope to meet up with you one day to tell you to your face. I'll be at the SEMA Show next month, are you going? If so, the first beer's on me.

Regards from Down Under.

aussiejohn

 

Aussiejohn,
Sorry, I won't be going to the SEMA convention.

I have been accumulating a lot of C2/C3 information ever since I ordered and purchased a new 1976 Vette as a GM employee. Back in the old days, Saginaw Steering Gear designed and manufactured virtually 100% of the GM steering systems. Fortunately, I began gathering Saginaw drawings and specs starting with the purchase of my 1976. Back then, I was also able to collect information on the C2 Vettes as well.

I remember Saginaw trying to convince Chevrolet engineering in the late '60s to convert the new C3 to the Saginaw 800 integral power gear. The changeover would have required a special gear housing and would have required Chevrolet to modify the Vette frame. Whether or not it was the cost of the frame change, politics, or other factors, the proposal was rejected and the next big steering change was to rack and pinion steering in 1984 with the new C4.

My brother-in-law had a new 1968 435 horse, C3 convertible. He managed to obtain one of the very few prototype 800 power gears with the special housing. He wacked and wittled the frame on his '68 to accept the prototype gear. I don't recall his actual evaluation of the installation. But I do know that based on his driving experience with his prototype gear installation, the gear(s) submitted to Chevrolet engineering had special valve(s) installed. That car now resides down in Florida.

BTW,the two photos with the comparison of the manual and power pitman arms came from another Corvetteforum member.

Jim Shea