Converting from Power Steering to Manual.
The factory P/S R&P was a very quick 2 3/4 turns lock to lock. This is great with the PS pump, but VERY hard to turn in parking lots with the lines looped. I needed a real manual rack, with something between 3 1/2 and 4 turns lock to lock to make it a little easier to turn.
The 89-97 Thunderbird never came with a manual R&P, and Mustang Rack and Pinions will bolt in, but there inner tie rods are a completely different size and thread. At the request of a couple of guys on SCCOA, Mike Sexton at Antioch Auto Parts, ph # 847-395-3660, made arrangements with Precision Rack and Pinion to custom make manual rack and pinions for the MN12 series Thunderbird.
These R&P use the standard 9/16 x 26 tooth input shaft that Ford uses on all of there manual racks. It is 3.75 turns lock to lock, which works out to about 18-1 ratio. It comes with the 9/16 x 26 tooth lower half of the rag joint. If you are using the standard rag joint, you will need to drill out the rivets, and bolt the new lower half to the old upper. The manual R&P is 3 pounds lighter than the Power one. If you are using a Flaming River shaft as part of the steering mod, you will need to order either of the below joints.
I measured the old R&P from the center of each tie rod end, then installed new tie rod ends to the new rack, and set them to the same measurment. This will make the toe in very close. To get equal steering travel in both direction, turn the rack full right, then left counting the exact number of turns, the divide that in half, and turn it to center. Point the steering wheel centered, and install the ujoint.
Go over all the nuts, bolts, and set screws, and double check for tighness. Grease the new tie rod ends. Now it is time to get the Toe-In set.
Update: I took the car out for a test drive today, and I am very pleased with
how easy it turns. I have 255/45/17 inch cruising tires on it now, and it turns so
much better. I can manuver around in my drive way, and pull into parking lot
spaces now like a normal car. The new R&P does have a little less travel from lock to lock, so can not turn as sharp, which makes the 3.75 turns lock to lock closer to 20 to 1 ratio. I am sure that with my 165/80/15 Skinnys on it, the steering effort will be easier than it was with P/S.
