Safety: Gear oil on the rear brake surfaces, including the parking brake shoes, reduces braking. Fix the leak and clean or replace contaminated parts.
Checks, in order
- Find where it leaks fromClean the housing and drive a short loop, then look. Oil around the pinion flange means the pinion seal, oil on the inside face of the wheel or backing plate means the axle seal, and oil from the cover edge means the gasket or sealant.easy $ · under about $50
- Fluid level and conditionLoosen the drain plug only to confirm you can undo it, then remove the fill plug first and check that oil is level with the bottom of the hole. Milky fluid means water got in; metal glitter on a magnet is worth noting.easy $ · under about $50
- Differential breatherFind the breather on the top of the axle housing and make sure it is open and not packed with mud. Many owners extend the breather line up to the frame rail so water and mud cannot be sucked in.easy $ · under about $50
- Rear brake contaminationIf the axle seal is leaking, pull the rotor and inspect the pads and the parking brake shoes inside the rotor hat for oil. Oily friction material needs replacing, not cleaning.medium $$ · about $50 to $500
- Noise diagnosisA whine that changes between throttle and coast points to ring and pinion wear or bearings. Change the fluid and re-check; if the noise stays, it needs a shop to measure backlash and bearing preload.hard $$$ · shop-level job, $500+
Applies to: US-market FJ Cruiser, 2007 to 2014, with the 1GR-FE 4.0L V6 (timing chain) and either the 5-speed automatic or the 6-speed manual. Assumes the part-time 4WD model with a floor-mounted transfer case lever; 2WD trucks skip the 4WD checks.
Tools and parts for these checks
Links below are Amazon affiliate links: as an Amazon Associate, toyotadata earns from qualifying purchases, at no extra cost to you. Confirm fitment for your exact truck before you order.
| ITEM | USED FOR | BUY |
|---|---|---|
| Gear oil for your truck | Changing diff oil to the factory spec | Shop on Amazon |
| Fluid transfer pump | Filling through the fill or check plug | Shop on Amazon |
| Axle seal | Replacing a leaking axle or pinion seal | Shop on Amazon |
| UV leak detection kit | Pinpointing exactly where a leak starts | Shop on Amazon |
Go deeper
The same problem on other Toyotas
Other drivetrain problems on the FJ Cruiser
- Clunk or thump from the rear when coming to a stop or pulling away
- Vibration that changes with vehicle speed, felt in the seat or floor
- 4WD will not engage, or the A-TRAC / VSC lights come on
More FJ Cruiser problems
- Rust on the frame, especially at the rear crossmember (Frame & Body)
- Steering wheel shimmy or flutter at highway speed (Steering & Suspension)
- Shudder or vibration under light throttle, or hunting and harsh shifts (automatic) (Transmission)
- Turn the key: click or nothing, engine won't crank (Starting & Charging)
- Engine cranks normally but won't start (Fuel & Ignition)
- Rough idle, stumbling or a misfire code (P0300 to P0306) (Fuel & Ignition)
All 16 FJ Cruiser symptoms in the interactive troubleshooter →
General guidance from owner experience. Confirm torque specs, fluid capacities and procedures in the factory service manual. Brakes, steering and anything structural: if in doubt, have a qualified shop inspect it before driving.