RC cars ยท Fix
RC car maintenance
By Paul Walsh Last reviewed
RC cars live hard lives: dust, mud, water and impacts. A short routine after each run and a bit more every few runs keeps a car fast and reliable, and catches small problems before they break something expensive.
After every run
- Unplug the battery and let the motor and ESC cool.
- Clean off dirt with a soft brush and compressed air (a can or a compressor at low pressure).
- Dry the car if it's wet, especially the bearings, motor and electronics.
- Look for damage: cracked arms, bent hinge pins, loose screws, damaged tyres.
- Store the battery correctly: LiPo at storage voltage. See LiPo battery safety.
Every few runs
| Check | What to look for |
|---|---|
| Screws | Loose screws, especially metal-to-metal; use thread lock |
| Gear mesh | A slight gap between pinion and spur; not too tight, not too loose |
| Wheel nuts | Tight, but not crushing the bearings |
| Bearings | Spin smoothly and quietly |
| Shocks | No leaks; even damping on both sides |
| Driveshafts and pins | Not bent or worn |
| Tyres | Glued to the rims, not split |
| Steering | Free movement, no slop |
Bearings
Spin each wheel by hand. Gritty, rough or noisy bearings need cleaning (with motor spray, then re-oiled) or replacing. Bearings are cheap; worn ones waste power and can damage hubs. Cars running on plastic bushings rather than bearings benefit from a full bearing set; see RC car upgrades.
Gear mesh
The pinion (on the motor) and spur gear must mesh with a tiny gap. Too tight and the motor works harder and gets hot; too loose and the spur strips. The classic method is a strip of paper between the gears while you tighten the motor, then remove it.
Shocks
Shock oil keeps the car stable over bumps. Leaking or empty shocks make the car bounce and handle poorly. Rebuild them when they leak, using the oil weight from the manual.
Differentials
Diffs let the wheels turn at different speeds in corners. Over time the oil or grease inside breaks down. Rebuild a diff when it feels notchy or the car's handling changes, using the fluid the manual recommends.
After running in water or mud
Dry everything thoroughly, blow water out of the bearings and re-oil them, and check the motor for water inside (brushed motors especially). Even "waterproof" electronics are only splash-proof in practice.
Nitro cars
Nitro cars need extra care: clean the air filter, use after-run oil when storing, check the clutch and glow plug. See nitro vs electric RC cars.
When something does go wrong, use RC car troubleshooting. Back to the RC cars hub.
Frequently asked questions
How do I clean an RC car?
Use a soft brush and compressed air first. For mud, a damp cloth or a light rinse if the electronics are waterproof, then dry thoroughly and re-oil the bearings.
How often should I replace bearings?
When they feel rough or gritty when you spin them by hand, or make noise. Cars driven in sand and mud need bearings far more often.
Can I wash my RC car with a hose?
Only if the manufacturer says the electronics are waterproof, and never with a pressure washer. Remove the battery first and dry everything afterwards.
Related guides
RC cars
RC car troubleshooting
Fault-by-fault fixes for RC cars: no power, glitching, poor steering, stripped gears, overheating and binding problems, with the likely cause of each.
RC cars
RC car upgrades worth doing
The upgrades that genuinely improve an RC car, from tyres and servos to bearings and motors, in the order to do them, and the ones that waste money.
RC cars
Nitro vs electric RC cars
Nitro and electric RC cars compared on speed, noise, maintenance, fuel and battery costs, and where in the UK each can actually be used.