When Pat Rego wanted to add power seat capabilities to the driver seat in her '89 "Seven Up" convertible, she didn't have far to look for expertise. Her husband, Merv, is not only her life partner but also her partner in Classic Creations of Central Florida, a Lakeland shop that specializes in vintage and Fox Mustangs. When Merv learned that replacement power seat assemblies sell for more than $400 from Ford, he decided to repair a used assembly that was left over from a previous customer repair.
The repair kit from Two Men...
The repair kit from Two Men One Garage includes a pair of heavy-duty forward/backward gear assemblies, new clevis pins and flexible driveshafts, and washers. Two Guys One Garage offers two kits for Fox-body Mustangs: FOR4 for '87-'93 and FOR6 for '94-'98.
By hooking a power seat switch to a battery, Merv was quickly able to determine that the motors (one for back and forth, another for up and down) still functioned. However, the plastic gears in the forward/backward gear assemblies were stripped, so while the motor worked, nothing moved. This is a common malady with Fox-body power seat mechanisms, usually caused when the seat tracks bind due to a lack of lubrication. An Internet search turned up Two Men One Garage, a company that offers power seat components for '87-'93 Mustangs, including replacement gear assemblies for $75. It's a basic R&R procedure. However, because the replacement gear assemblies are slightly larger than the factory unit, some minor modifications are required.
The Fox-body power seat mechanisms...
The Fox-body power seat mechanisms are part of the seat track. The pair of forward/backward gear assemblies and shafts are located inside the seat track rails.
Begin the disassembly by removing...
Begin the disassembly by removing the Torx bolt that secures the gear screw block to the threaded gear shaft. You'll need to repeat on the other side.
Use an air grinder or similar...
Use an air grinder or similar tool to grind off the mushroom end of the pin that retains the gear assembly. Use a punch to push the pin out of the assembly.
Lift the gear assembly and...
Lift the gear assembly and threaded shaft, then maneuver it away from the metal strap and disengage the flexible drive shaft. Remove the gear screw block by unthreading it from the shaft; it will be reused on the new shaft.
Because the replacement gear...
Because the replacement gear assembly is slightly larger than the original, you'll need to trim off a section of metal on the outside of the seat frame. After marking, use a saw to make the cut.
The mounting holes in the...
The mounting holes in the seat track must be slightly elongated to accommodate the larger gear assembly.
Slide the new gear assembly...
Slide the new gear assembly into the strap and secure with the new clevis pin. You will need to bend the metal strap slightly to adjust for the larger gear assembly.
Secure the clevis pin with...
Secure the clevis pin with the supplied washer and cotter pin.
Reinstall the shaft block...
Reinstall the shaft block by threading it onto the shaft, then secure with the original Torx screw. The Two Men One Garage instructions provide adjustment tips.
The replacement driveshaft...
The replacement driveshaft is slightly longer than the original. For a clean installation, Two Men One Garage recommends trimming the rubber hose (which protects the driveshaft) and modifying the plastic end caps.
With the hose trimmed, slide...
With the hose trimmed, slide the driveshaft into the gear assembly and motor. Remov-ing the motor from the seat frame makes it easier to maneuver the shaft into place.
Here's the new shaft in place....
Here's the new shaft in place. You'll need to repeat the process on the other side. Be sure to lubricate both the gear shafts and the seat tracks.