Muscle Mustangs & Fast FordsHow To Drivetrain
How to Install the NPD Rack and Pinion Steering Unit on a Fox Mustang
Rack Em Up! Get precision steering and durability with a power rack-and-pinion steering unit from National Parts Depot
Rack-and-pinion steering is one of the Mustang’s greatest engineering refinements ever because it eliminated the slippery slop of antiquated worm and sector steering, enabling you to put your Mustang right where you pointed the steering wheel. What makes power rack-and-pinion steering better than worm and sector are fewer moving parts and a more precision demeanor. As its name implies, rack-and-pinion steering consists of two basic moving parts: a toothed linear rack and a pinion gear to drive it left and right.
Of course there’s more to rack-and-pinion steering than rack-and-pinion, especially if you have a hydraulically boosted steering rack. The steering shaft is tied to the pinion in order to keep steering should the hydraulic system fail. Incorporated into the steering shaft is a spool valve, which directs hydraulic pressure to one side of the hydro-boosted rack or the other based on steering input. Rarely do rack-and-pinion steering units give us trouble. And when they do, most of the time it’s because they’re worn out and leaking. They serve reliably well in excess of 100,000 miles and will easily outlast the tie-rod ends, which become worn out and need replacing from time to time.
According to the National Parts Depot website, many types of steering racks were used on 1979-1993 Fox body Mustangs. When you order your NPD power steering rack, it is important to determine which rack you have and what must be ordered. Here’s how they stack up.
NPD 1979-93 Mustang Steering Racks
NPD’s massive Fox body parts inventory also includes a wide variety of steering components for 1979-1993 Mustangs, such as rubber and urethane steering rack bushings, adjustable billet bushings, tie-rod ends, and all mounting hardware.
|Model Year||Type Rack||Application||Cost|
|1,979.00||M-3504-2A||Power Steering, TRW Type||$129.95; $150.00 core charge|
|1,979.00||M-3504-3A||Power Steering, Ford Type||$129.95; $150.00 core charge|
|1980-1981||M-3504-2B||Power Steering, TRW Type||$129.95; $85.00 core charge|
|1,980.00||M-3504-4A||Power Steering, Ford Type||$129.95; $85.00 core charge|
|1981-1984||M-3504-5A||Power Steering, Ford Type||$99.95; $185.00 core charge|
|1982-1984||M-3504-7A||Power Steering, TRW Type||$99.95; $185.00 core charge|
|1985-1993||M-3504-7B||Power Steering, Except Handling Package||$99.95; $185.00 core charge|
|1983-1993||M-3504-8A||Power Steering, Handling Package||$99.95; $150.00 core charge|
1. National Parts Depot shipped us this complete remanufactured power rack assembly, including power steering pump and hoses. This is the M-3504-8A Ford steering rack for the 1983-1993 Mustang GT, SVO, SVT Cobra, and LX with a 5.0L V-8. The serpentine power steering pump pulley is press-on and must be acquired from the pump you are replacing. You’re going to need a puller and an installation tool.
2. We’ve opted to go with a Maximum Motorsports steering coupling and billet aluminum mount bushings for our NPD steering rack. NPD rubber bushings provide outstanding rack support. For the kind of driving expected for our 1989 Mustang GT, we’re going with the billet bushings for rock-solid integrity during harsh driving. This steering coupling is failsafe and provides a precision connection between driver and steering rack.
3. Steering rack removal begins with tie-rod end cotter pins and castle nuts.
4. You can use a pickle fork or give these tie-rod ends a whack with a hammer as shown. The extreme hammer shock will cause each rod end to pop from its taper fit attachment point.
5. This is the tie-rod end toe adjustment. Break the lock nut loose. Mark the tie-rod end and slowly back it out of the threaded rack inner tie-rod, counting the number of turns as you back out. Write down the number of turns for each side. This approach gets toe-in close enough to get you to an alignment shop.
6. Our project 1989 Mustang GT’s engine is out for a power build at JGM Performance Engineering. This enables us to show you how the power rack is installed and configured. Two mounting points secure the rack to the subframe.
7. This is the 1979-1993 Mustang steering shaft and coupling. The coupling at the rack, known in the industry as a rag joint, deteriorates from heat and climate exposure. Although the rag and universal joints are a failsafe, the steering shaft should be replaced whenever you replace the rack.
8. Steering shaft removal begins with disconnection at the steering column with 11/16- and 5/8-inch box-end wrenches and bolt removal. It is ironic that these are SAE sizes considering how much of a Fox-body Mustang is metric.
9. The rag joint is disconnected at the steering rack as shown using a 1/2-inch socket.
10. The rack mount bolts are next using an 18mm box end and socket.
11. The steering rack is manipulated off the mounting bolts as shown to where the bolts can be removed from behind the subframe. The rack is moved forward off the mounts.
12. The rack can be removed via either side of the vehicle. It is an easier path to the right-hand side because there are fewer components in the way.
13. This sleeve supports the rack-and-pinion unit mounts. If you’re going to use stock mounts and bushings, these sleeves should be installed as shown here. If you’re going with aftermarket billet aluminum mounts, modifications need to be made to these sleeves.
14. Here’s the rack-and-pinion mount sleeve in stock form with the mounting bolt just below the end. With the bolt fully seated, the treaded shank protrudes nearly an inch.
15. Because we’re installing the new NPD power rack using Maximum Motorsports billet mounts, these mounting sleeves must be cut flush with the subframe. The sleeve is scribed to indicate where it needs to be cut. If your mounting sleeves are worn out or damaged beyond service, NPD has new sleeves for Fox-body rack mounts.
16. We’re cutting each mounting sleeve to the scribed lines to make room for the billet mounts. If you’re installing new rubber or urethane mounts, do not cut or modify the sleeves.
17. The installed modified sleeves should be flush with the subframe and look like this.
18. The power steering pressure hose from the pump sports an O-ring seal fitting like this. Lubricate this fitting and seal with power steering fluid only.
19. With the fitting generously lubricated, carefully thread and tighten as shown. Do not overtighten. This line should remain mobile when tight.
20. This is the low-pressure return line, which carries spent fluid from the rack back to the power steering pump.
21. The low-pressure return line is threaded into the control valve (steering shaft) and tightened. Again, do not overtighten. Keep in mind that not all 1979-1993 power steering lines are the same. This particular application is 1983-1993 handling package only.
22. In a stock installation we would be inserting the new rubber or urethane mounts prior to rack installation. We’re installing aluminum billet rack mounts from Maximum Motorsports, which will give our NPD rack solid security for the kind of mountain twisty driving expected.
23. Before the rack is installed each mount gets this flat washer then a beveled washer designed to center the rack on each mount.
24. Our remanufactured NPD rack in rich black satin is positioned and mounted as shown. Again, the best approach is from the right-hand side for easy access.
25. The NPD power rack-and-pinion unit is secured and readied for fastener installation. Note that the concave beveled washers are located on the backside against the convex beveled washers. Flat billet washers are located in front against the flat washers and locknuts.
26. The Maximum Motorsports steering shaft/coupling assembly provides a more solid connection between the steering wheel and our NPD steering rack. This is a steering shaft designed for manual rack-and-pinion operation, which means it can stand up to anything. It gives our 1989 Mustang GT convertible a crisp feel at the wheel.
27. To get the steering shaft and rack properly indexed, the rack is turned from lock to lock to establish center. Once the center is ascertained, the sector (pinion) shaft is marked at 12 o’clock and the steering wheel centered at 12 o’clock. This establishes true steering center with a uniform number of turns lock to lock and back to center.
28. The flexible steering shaft is splined into the pinion shaft and the Allen screw tightened. It is suggested you use a thread locker on this screw. The steering shaft to flex shaft bolt is reinstalled and tightened.
29. Steering rack bolts are torqued to 45 lb-ft. It is suggested you do this in half values on each side; that is, torque each bolt to 22-23 lb-ft, then the full 45 for uniform torque. It is suggested you use a thread locker on these fasteners.
30. Tie-rod ends are installed using the same number of turns as removal to get close to what it was with the original rack. A front-end alignment is suggested.
31. Tie-rod ends are secured at each spindle as shown. New cotter pins are installed and bent over the stud, then trimmed to where they cannot injure anyone.
32. New power steering return hoses are installed next as shown. These return lines go to the power steering fluid cooler across the radiator support.
33. The installed NPD power rack-and-pinion steering assembly should look like this. Double-check all fasteners for security.
34. This is the power steering pressure hose at the pump. Check this hose for proper routing and header/exhaust manifold clearance and any contact points where chaffing could occur.
35. This is the low-pressure return hose at the pump.