D-501A Lang Tailwheel

  1. How do I re-grease my wheel bearings? First remove the three hub cap screws. Next remove the felt washer. Use a clean shop towel to remove as much grease as you can from the wheel cavity. Straighten the cotter pin as much as you can, take care not to crack or dent the thin lip , remove it from the castle nut. Remove castle nut and thin washer. Remove wheel from axle. Set first bearing aside .

  1. It recommended that the Garlock seal be replaced whenever it is removed. It is easily damaged. With care (and a little luck) it can be removed and installed again. Using a round bar (1” dia) slide it through the axle hole and lightly tap out the Garlock seal. It is a light press fit. Set the bearing and the small Garlock spacer aside. Inspect the Garlock seal for deformation and damage. Discard and replace if damaged.

  1. Using a solvent clean the old grease from both bearings. Towel dry. Never use compressed air to “spin dry” a bearing! Since the bearing is lube free you can damage the rollers. Make sure the bearings are clean and dry, and repack them until the new grease is pushing through the rollers and races. Set them aside on a clean surface.

  1. Using a clean shop towel clean all the old grease from your hubs and the races that are pressed into them. Inspect your hubs for cracks and damage. Now is a good time to check your tire for wear and damage.

  1. Re-assembly: There two hubs, one smooth (inner) and one raw casting in appearance (outer). The smooth one (inner) is the side the Garlock spacer & seal will go. Lay the wheel flat on a benchtop with the inner hub up. Insert one of the re-greased bearing cones tapered side down into the hub race. Insert the Garlock spacer on top of the bearing. Place the Garlock seal on top of the spacer. Using a flat smooth piece of sheet metal, nylon etc, lightly tap the Garlock seal into the hub until it is flush with the top lip. Never use a hammer or anything other than a flat surface to tap it in. You will feel it bottom out on the lip of the hub.

  1. Now you have a Tire hub assembly with a bearing and Garlock seal and spacer installed on one side. Clean and inspect the axle shaft for damage. Keeping the wheel square with the axle, gently install the wheel onto the axle until the Garlock seal bottoms out on the axle shaft (larger dia). Lay the assembly on the bench axle up, and install the other bearing, pushing it as far down as possible. Install the thin washer on top of the bearing, install the castle nut. Using a socket tight the castle nut until the wheel binds (won’t spin freely). Back off the castle nut one or two slots on the nut. The wheel should be free now to rotate freely. Install a new cotter pin and bend the tabs down to secure. Not done yet! Now fill the grease free area around the nut and cotter pin with grease until flush with the top of the lip on the hub (this helps seal out water and debris). Clean all excess grease off the outer hub surfaces. Install the felt washer over the hub lip. Install the hub cap .