1965 Steering Boxes
The Ford Mustang shop manuals show three different steering boxes.
1) HHC-AT is the stock Mustang box used with manual steering. The ratio is 19:1. It is often referred to as 20:1.
2) HHC-AX is the special maunal steering box standard on the GT Mustangs and cars with heavy duty suspension. The ratio is 16:1.
3) HHC-AW is for cars with power steering. The ratio is 16:1.
The only difference between the power steering unit and the special manual is the amount of pre-load on the worm shaft bearing (4-5in./lbs. on the special manual and 3-4 in./lbs. on the power steering.)
Once the Pitman and idler arms are connected the ratios are calculated differently. The standard Mustang ratio is 19:1 without the Pitman and idler arms and 27:1 with. The special box (used on the Shelby Mustangs) without the Pitman and idler arms is 16:1. With the stock Pitman and idler arms, the ratio is 22:1, with the Shelby American Pitman and idler arms, the ratio is 19:1. Of course, the Shelby setup provided quicker steering.
Yes, you can use the Shelby Pitman and idler arms on any stock Mustang for much quicker steering.
This page last edited on Tuesday, April 11, 2000