Animated service guide
When to Service a Dirt Bike Shock
A full shock service means new oil, new seals and bushings, a look at the valving and shaft, and a fresh nitrogen charge. Most riders send that to a suspension shop, and this guide is honest about why. What you can do at home is know when it is due, spot the signs, check the shaft, seal, mounts and bearings, and tell the shop exactly what you need.
The animated guide loads here. Every step is also written out below.
Before You Start
Tools
- Lift stand
- Flashlight
- Clean rags
- Sockets for the shock bolts
- Torque wrench
Parts And Supplies
- Grease named in your manual for the shock bearings
Safety
- The shock holds nitrogen under high pressure. Never open it, heat it, or drill it.
- Support the bike and the swingarm before you pull a shock bolt.
Step By Step
Know what a shock service is
The shock turns bump energy into heat in its oil. Over hours the oil breaks down and the seals and bushings wear. A service replaces the oil, seals and bushings, checks the shaft and valving, and recharges the nitrogen.
Shock oil Bike Spec Source KTM / Husqvarna / GASGAS MX SAE 2.5 shock fluid KTM 250 SX-F 2024 owner’s manual, PDF p. 156 Your shop uses the oil the shock maker specifies.
Go by hours first
Shock oil wears out with use long before it looks bad. Track hours and plan the service at the interval below. Harsh conditions shorten it. KTM says rain, mud, sand and heavy use can call for shorter intervals.
Shock service interval Bike Spec Source KTM / Husqvarna / GASGAS, race or enduro Shock service every 45 h KTM 250 SX-F 2024 owner’s manual, PDF p. 42 (check the heim joint for play at 45 h); same 45 h on the enduro models. KTM 250 XC-W / 300 EXC / 300 XC-W 2026 OM, PDF p. 55; KTM 450 XCF-W / EXC-F 2025 OM, PDF p. 54; Husqvarna TE 250/300 2026 OM, PDF p. 55 Yamaha YZ250F / YZ450F (race) Grease bearings every 7.5 h Yamaha YZ250F 2026 owner’s service manual, PDF p. 94 (inspect every race, grease bearings every 3rd race; no hour-based oil change listed) Honda CRF450X, CRF250F (trail) Inspect only, 1,200 mi No shock oil change listed. Inspect the suspension every 1,200 mi (2,000 km) or 12 months. Honda CRF450X 2025 OM, PDF p. 47; CRF250F 2025 OM, PDF p. 53 Honda’s 2025 owner’s manual chart has no shock service line. How fast a shock wears depends on the rider and the terrain, so ask your suspension tech how worn the parts were.
Spot the signs
The rear keeps bouncing after bumps, kicks on jump faces, packs down in whoops, or turning the clickers barely changes anything. Those point to tired oil. Oil on the shaft or body means a leaking seal, and Yamaha says a leaking shock needs service or replacement.
Shop tip. A harsh rear can also be dry linkage bearings. Check the linkage before you blame the shock.
Check the shaft and seal
Clean the shock, then slide the bump rubber down and look at the shaft and the seal head. A wet ring of oil, or a pit or scratch on the chrome, means the seal is going. Yamaha says a bent or damaged rod or any oil or gas leak means the shock needs work.
- Flashlight
- Clean rag
Check the mounts for play
With the rear wheel off the ground, lift and drop the wheel a little and feel for a clunk at the top and bottom shock mounts. KTM checks the shock heim joint for play at its 45-hour service. Play there is a bearing job, not an oil job.
Grease the shock bearings
Pull the shock and clean the lower bearing and its seals. Yamaha greases the shock bearings every third race and uses molybdenum disulfide grease on the lower bearing, but not on the bearing’s outer race. Refit and torque both bolts.
- Sockets
- Torque wrench
- Grease
Shock mounting bolts Bike Spec Source KTM / Husqvarna / GASGAS MX 60 Nm top and bottom KTM 250 SX-F 2024 owner’s manual, PDF p. 160 Yamaha YZ250F 2026 Upper nut 56 Nm, lower nut 53 Nm Yamaha YZ250F 2026 owner’s service manual, PDF p. 69 Yamaha YZ450F 2026 Upper nut 56 Nm, lower nut 53 Nm Yamaha YZ450F 2026 owner’s service manual, PDF p. 67 Honda’s owner’s manual prints no shock bolt torque. Use your service manual.
Careful. Hold the swingarm when the lower bolt comes out so it doesn’t drop.
Leave the nitrogen to a shop
Behind a separator in the reservoir sits nitrogen under high pressure. It keeps the oil from foaming. Opening the shock without the right tools can launch parts, and recharging needs a nitrogen bottle and gauge.
Nitrogen pressure Bike Spec Source KTM 250 SX-F (WP XACT) 10 bar (145 psi) KTM 250 SX-F 2024 owner’s manual, PDF p. 156 (same on 450 SX-F p. 161, 250 / 300 SX p. 137) Yamaha and Honda owner’s manuals give no charge pressure. The shop sets it from the shock maker’s data.
Careful. Yamaha says not to open the shock, not to heat it, and to take a worn-out one to the dealer to release the gas before disposal.
Tell the shop what you need
Ask for new oil, seals and bushings, a shaft check and a nitrogen recharge to spec. Give them your hours since the last service, your weight in gear and your clicker settings, so the shock comes back set up for you.
Shop tip. Ask the shop to check the spring rate for your weight while the shock is apart. KTM lists springs by rider weight in full gear.
Sources
Log It And Know When It Is Due Next
MotoMind logs engine hours and every service job with notes, parts and cost, and shows each task as upcoming, due or overdue. Available to download on iOS.
