Is the centerlink (drag link) different on power steering cars than on manual steering cars? I'm converting from manual to power steering on my 72 GS using a kit from Classic Performance Products. The new pitman arm will not draw up far enough onto the center link to allow me to fully tighten the castle nut. When I mic the new pitman arm, the tapered hole is somewhat smaller than the tapered hole in the old manual box pitman arm. The pitman arms have different splines, so I can't reuse my old pitman arm. My only conclusions are that either the center links are different, or maybe my new pitman arm just was not machined properly. Any thoughts?
I have done many conversions and have always used the same center link. your pitman arm must be machined wrong or wrong application.
I've converted quite a few cars from power to manual and there are two different sizes, I just can't remember the details! The '60s cars may be different than the '70s, but the box would be the same, which means the hole in the pittman arm may be wrong. I'm trying to find the info from when I converted my SportWagon from power to manual, but I can't find it. If I come up with any details, I'll post them here!
On a A-Body Pontiac the centerlinks are different, one has a 45* or so bend in it where the pitman arm bolts up, I think its manual steering one but not sure. I never changed one out on a conversion, seemed to work fine, I'm thinking your problem is your new pitman arm not machined correctly.....
Well, After re-reading an internet article in which a classic performance kit was installed on a Chevelle, I'm pretty sure that there are 2 different pitman arm hole sizes. The kit did not include a drag link or idler arm. My car seems to be pretty much original, so I think the drag link is a 72. The 64,68-72 drag links are said to be 7/8", instead of 13/16" for 65-67. No one can tell me where these measurements are taken from. Is it the hole size for the idler arm & pitman arm, the overall diameter of main body? I know that the big (splined) end of the pitman arm is a different size for power and manual. If the drag link has just the hole size that is different, then it would seem that there are two different pitman arms for power steering, and two different pitman arms for manual steering. At any rate, I called Classic performance and finally convinced them to send me the other style pitman arm. So, in a week or so I should know more about all this silliness. One more problem I'm having is very little assist at idle. If I rev the motor a little, then the assist kicks in. Also, as the motor reaches full temp, the assist goes away. Classic says to keep turning the wheel lock to lock to bleed more air out of the system. I've done this so much my arms are sore. It is has improved a little. Anyone else had this problem? Jeff
Re: Centerlink, etc. Hi Jeff, I'm going thru the same situation. My car is 66 Skylark w/ Olds 425 engine. I did the changeover using rebuilt Olds pump and rebuilt Skylark gearbox. The pitman arm I had was too small - came from a boneyard with a changeover kit, so can't tell what car it came off of. I bought a new centerlink - it also takes the larger hole. So, I borrowed a reamer from a towing co. and enlarged the hole. Problem solved. Don't expect everyone to have the correct reamer, though. The real solution is invest $90 in a new pitman arm. As to the assist at idle problem, mine does the same. I suspect maybe the relief valve setting in the pump is wrong (I posted the question at BCA). By the way, I've given up on the rebuilt nonsense - new parts aren't that much more, and they fit & work! BobF
Problem Solved I received my replacement pitman arm from Classic Performance. The new part went on without any problems. The only difference between the 2 arms is that the tapered hole for the center link is slightly larger, but that is exactly what was needed. The hole is only a few thousandths bigger, the difference can't be seen with the naked eye. The part number cast into them was the same except the one with the larger hole had and extra "69" at the end. By the way, my assist has straighten itself out. After driving around a little the last few weekends, it is working pretty well. Maybe it was just air that was in the lines/pump.
