MX Gear and MX Parts
1. Bearing Removal
Please take time and be very careful not to damage the parts and their mating surface in the wheel hub.
Use a long punch (should have a good flat/square edge)
Remove any Circlips or retainers. Insert the punch into the wheel and catch the edge of the bearing on the other side. Using a hammer, hit the punch and work around the entire circumference of the bearing slowly, keep bearing even when removing.
The bearing and seal will eventually be pushed out of the wheel hub. The second bearing can be moved using a punch, a long socket or other suitable driver.
Very Important Note: The bearings will be damaged during the removal process and should not be reused. The hammer blows transmit their impact through the balls causing small flat spots, which will cause the bearing to quickly fail if reused.
Inner Spacer: Check the bore to make certain it is clean and the axle easily passes through it. Check each end for wear and burrs. The edges must be square to seat properly against the new bearings. If the old bearings failed it is a good idea to confirm that the center spacer has not been damaged. Make sure the inner space is the same length or slightly longer than the bearing stops in the hub or carrier.
Wheel Hub: Clean the hub, removing any dirt and corrosion, if the surface is not smooth when installing parts this can damage parts and their mating suface. Make certain not to remove metal. This will adversely affect bearing fit.
Outer Wheel Spacers: Clean the outer wheel spacers and inspect them for wear on either end as well as wear on the outer surface where it makes contact with the seal. If the spacers are excessively worn they should be replaced.
3. Bearing Installation
Note 1: Improper installation can cause bearing damage and dramatically reducing bearing life.
Note 2: Heating the wheel hub will cause the hub to expand slightly and will make bearing installation easier. A paint stripping heat gun or a touch with flame can be used.
Note 3: Do not overheat any part if using heat to install bearings
Note 4: Never hit bearing or any parts directly with a hammer this will damage and will reduce life of the part/parts
Follow the simple rules below to successful bearing installation:
1. Apply pressure ONLY to the outer race of the bearing.
2. Apply pressure evenly so the bearing remains square to the wheel hub.
3. Seat the first bearing fully.
4. Remember to place the inner spacer between the bearings.
5. Tap the second bearing in until the inner race just touches the center spacer. See fig 1 Fully seating the second bearing may cause both bearings to become side loaded causing premature failure.
See fig 2
6. If the center spacer is loose after the second bearing is installed this may be a sign that the center spacer is too short and needs to be replaced or the second bearing needs to be taped in further.
A lose or worn center spacer can cause the bearing to be side loaded in the opposite direction after the axle is torqued down. See fig 3