Animated service guide
How to Check and Replace Dirt Bike Wheel Bearings
Each wheel spins on two sealed ball bearings with a spacer between them. Water past the seals washes out the grease and rusts the races. A worn bearing lets the wheel wobble, feels gritty, and can seize. The check takes ten minutes. Replacing them takes a puller, a driver and some care.
The animated guide loads here. Every step is also written out below.
Before You Start
Tools
- Stand that lifts the wheel
- Bearing puller
- Socket or driver that matches the bearing outer race
- Hammer
- Flat screwdriver and a rag
- Torque wrench
Parts And Supplies
- New bearings and oil seals for both sides
- Grease for the seal lips and spacers (KTM long-life grease, Yamaha lithium-soap grease)
Safety
- Axle nuts and pinch bolts are safety fasteners. Torque them to your manual.
- Keep grease off the brake discs. KTM warns that grease on a disc cuts braking.
Step By Step
Get the wheel off the ground
Put the bike on a stand so the wheel you are checking hangs free and spins without touching anything. Check both wheels the same way.
- Lift stand
How often to check wheel bearings Bike Spec Source KTM / Husqvarna / GASGAS, race or enduro (wheel bearing play) Every 15 h KTM 250 SX-F 2024 owner’s manual, PDF p. 41; KTM 2026 XC-W OM, PDF p. 54; KTM 450 XCF-W 2025 OM, PDF p. 53 Yamaha YZ250F / YZ450F race (check the bearing) Every 3rd race (7.5 h) Yamaha YZ250F 2026 owner’s service manual, PDF p. 94 Honda CRF250R / CRF450R race (no bearing line; wheels and tires inspected) Each race (2.5 h) Honda CRF250R 2025 owner’s manual, PDF p. 44 Honda CRF450X, CRF250F trail (no bearing line; wheels and tires inspected) Every 600 mi Every 600 mi (1,000 km) or 6 months, after a first check at 100 mi. Honda CRF450X 2025 OM, PDF p. 47; CRF250F 2025 OM, PDF p. 53 Check them whenever the wheel is out, and after wet or muddy rides.
Rock the wheel for play
Grab the tire at the top and bottom and push and pull against each other. Do the same at the front and back. A good bearing feels solid. Any knock or click you feel at the hub means play, and a loose wheel bearing only gets worse.
- Your hands
Shop tip. Rocking and spinning by hand is shop practice, not a manual procedure. Hold the brake on while you rock it. If the knock goes away, the play is in the bearings, not the brake.
Spin it and feel
Give the wheel a spin and rest a finger on the hub or the axle end. It should turn smoothly and quietly and coast to a stop. Grinding, a gritty feel or a wheel that stops short means a dry or rusty bearing.
- Your hands
Know what kills them
A pressure washer forces water past the seal lip. The water mixes into the grease, the grease washes out and the races rust. KTM says not to aim the jet at bearings, and Honda says not to use a high-pressure washer at all.
- Garden hose
Careful. KTM says to keep the pressure washer nozzle at least 60 cm (23.6 in) from bearings. Honda says if you do use one, keep it off the steering head bearings and suspension pivots, and the same logic applies to the hubs.
With the wheel out, check each bearing
Pull the axle and the spacers. Turn each bearing’s inner race with a finger. Replace it if it feels rough, notchy or loose, or if the seal is torn. KTM checks the bearings every time a wheel goes back in.
- Your finger
Pull the seals and bearings
Clean the hub. Pry the oil seals out with a flat screwdriver, with a rag under it so you don’t mark the hub. Then pull the bearings with a bearing puller. Old bearings and seals don’t go back in.
- Flat screwdriver
- Rag
- Bearing puller
Shop tip. Yamaha’s manual uses a puller and no heat. Some shops warm the hub around the bearing so it lets go easier. That is shop practice, not a manual step. Never use a flame near the tire or seals.
Press new bearings on the outer race
Fit one side first, then the spacer, then the other side. Drive each bearing in square with a socket that matches the outer race. Marks face out. Yamaha fits the left side first on the front wheel and the right side first on the rear.
- Bearing driver or socket
- Hammer
Careful. Never drive on the inner race or the seal. That loads the balls and dents the races before the bearing ever turns.
New seals, grease the lips and spacers
Press the new oil seals in with their marks facing out. Put a light coat of grease on the seal lips and on the faces of the spacers so water has a harder time getting in.
- Grease
- Seal driver or socket
Refit the wheel and torque the axle
Lightly grease the axle, slide it through, and tighten the axle nut or spindle screw to spec. On the front, pump the brake and bounce the fork before you tighten the pinch bolts or fork stub screws, so the fork legs line up.
- Torque wrench
Axle torque, front / rear Bike Spec Source KTM / Husqvarna / GASGAS MX (front spindle screw M20x1.5 / rear nut M22x1.5; fork stub screws M8 15 Nm) 35 / 80 Nm KTM 250 SX-F 2024 owner’s manual, PDF p. 110-111 and 160 Yamaha YZ250F / YZ450F (front axle nut M18 / rear axle nut M22; front pinch bolts M8 21 Nm) 115 / 135 Nm Yamaha 2026 YZ250F OSM PDF p. 68; YZ450F OSM PDF p. 66 Honda’s owner’s manual prints no axle torque. Use the value from your service manual. These are safety fasteners.
Street bike? Check the steering head too
The same stand gets you a steering head check. With the front wheel off the ground, rock the fork legs forward and back and turn the bars lock to lock. You want no play and no notches. If you find either, adjust or service the steering head bearings.
- Your hands
Sources
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