Steering Geometry correction effort
This is another "retro post". This was work I had done prior to putting on the wider tires. The problem was that I had my power steering box rebuilt by Steer and Gear, to the TA specifications. I purchased the longer pitman arm and the longer idler arm which was not part of the original TA setup. From the factory, the cars had longer travel for non-TA steering boxes with a shorter arm. Once you add the longer arm you need to limit the travel of the arm so that you don't over travel the steering. Steer and Gear did a fantastic job by the way and Carmen still answers the phone and is a wealth of knowledge. Couldn't be happier with them!
On to my issue. Once I had installed these new parts, I had one tie rod almost an inch shorter than the other and no matter what I did all the witness marks lined up. The wide teeth on the sector shaft were parallel and perpendicular to the body, so I was pretty sure it was not the box. After scouring the forum for any unusual K-frame, tie rod, steering arm or idler arm issues, I could not find anyone that had a similar issue. I document this here so if someone else has this issue maybe it can be of help. For baseline, I have a 340 base car that i've updated with the TA box, longer pitman and longer idler.
I've uploaded two photos to illustrate the issue. What is documented are photos of the outside edge of the tire as it traces a path on the ground. basically I put the steering wheel straight and drew a reference 90 degree line straight out at the center of the tire to identify straight ahead and then turned the wheel right and left and traced the angles that the tire left. Note that the intersection of the two lines at extreme angles is in front of the center of the tire on the Drivers side and behind the center line of the tire on the Passenger side. This is what prompted me to purchase the QA-1 upper control arms so I could get much more positive caster in the front end and make them the same side to side. Well worth the extra bucks as it transforms the steering feel.
Another thing to note is that the wheel turned much farther to the right than the left.
After doing all this research I came to conclusion that the longer pitman arm needed to move one tooth on the steering box to the left as it was installed in the car. All the other reference marks, from the steering wheel to the teeth on the steering box all lined up per the factory shop manual and documentation on this forum and others as well as advice from Carmin. I came to this conculsion from the photo of the arms. If you look at the spline they are lined up (short arm to long arm). the white chalk mark on the arm should be parallel to the drag link. If you look at this photo clearly the pitman arm is at a different angle than the shorter arm.
Sure enough, I filed the teeth to add another groove in them bolted it on in the new location and everything center up (both tie rods now about 12" long) steering wheel straight and same angle on both front tires right or left.
On to my issue. Once I had installed these new parts, I had one tie rod almost an inch shorter than the other and no matter what I did all the witness marks lined up. The wide teeth on the sector shaft were parallel and perpendicular to the body, so I was pretty sure it was not the box. After scouring the forum for any unusual K-frame, tie rod, steering arm or idler arm issues, I could not find anyone that had a similar issue. I document this here so if someone else has this issue maybe it can be of help. For baseline, I have a 340 base car that i've updated with the TA box, longer pitman and longer idler.
I've uploaded two photos to illustrate the issue. What is documented are photos of the outside edge of the tire as it traces a path on the ground. basically I put the steering wheel straight and drew a reference 90 degree line straight out at the center of the tire to identify straight ahead and then turned the wheel right and left and traced the angles that the tire left. Note that the intersection of the two lines at extreme angles is in front of the center of the tire on the Drivers side and behind the center line of the tire on the Passenger side. This is what prompted me to purchase the QA-1 upper control arms so I could get much more positive caster in the front end and make them the same side to side. Well worth the extra bucks as it transforms the steering feel.
Another thing to note is that the wheel turned much farther to the right than the left.
After doing all this research I came to conclusion that the longer pitman arm needed to move one tooth on the steering box to the left as it was installed in the car. All the other reference marks, from the steering wheel to the teeth on the steering box all lined up per the factory shop manual and documentation on this forum and others as well as advice from Carmin. I came to this conculsion from the photo of the arms. If you look at the spline they are lined up (short arm to long arm). the white chalk mark on the arm should be parallel to the drag link. If you look at this photo clearly the pitman arm is at a different angle than the shorter arm.
Sure enough, I filed the teeth to add another groove in them bolted it on in the new location and everything center up (both tie rods now about 12" long) steering wheel straight and same angle on both front tires right or left.
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