Pedal Adjustment Gear - Gen 2 (2003-2006) Ford Expedition

thingiverse

These are the worm gears that adjusts the pedal positions on a gen 2 (2003-2006) Ford Expedition. I had to replace both on my vehicle. The OEM gears are notorious for splitting, causing the pedal adjustment mechanism to jam. I'm providing two versions of each gear: The "Helical" versions are an exact replica of the original gears. They have involute helical teeth geometry. This geometry does work, but is not ideal for use as a worm gear because the mate between worm and gear is a single contact point. The "Hobbed" versions are better-designed. They replicate the geometry of a hobbed worm gear, which allows the loads to be spread across a large area of the teeth, as apposed to a single contact point between the worm and the gear. Both gears must have a thread inside the bore. I modeled the threads for the accelerator pedal gears. However, because it proved so difficult to get the thread tolerances perfect, for the brake pedal gear I only modeled a smooth oversized hole through it. Rather than printing the threads into the brake gear, I reused the threaded insert in the original gear - though I did have to machine the outside of the insert to snugly press-fit into the 3d printed gear. For my vehicle, I used a FormLabs SLA printer, and printed with the FormLabs Tough resin. Considering how strong this resin is, I anticipate many years of trouble free use; but I will update if the gear ever breaks or wears. If you print this, make sure while slicing to remove any supports that contact the teeth or the internal threads as they will be difficult to cleanly remove after printing.