Checks, in order
- Vacuum hoses to the actuatorFollow the lines from the vacuum switching valve to the front differential actuator. Look for cracks, pinched spots or loose connections.easy $ · under about $50
- Vacuum switching valveCheck that it passes vacuum when the 4WD is selected. A stuck valve will prevent engagement.medium $ · under about $50
- Front axle disconnect actuatorInspect for rust and a stuck shaft. Cleaning and lubing may free it, or the actuator may need replacement.medium $$ · about $50 to $500
- Transfer case shift and fluidCheck the fluid level and the linkage. A tight or stiff shift may be a dry linkage or low oil.medium $ · under about $50
- Test drive in 4 high on loose groundFeel for the front axle engaging. Binding on dry pavement is normal, so test on dirt or gravel.easy $ · under about $50
Applies to: 1996 to 2002 4Runner with the 2.7L 3RZ-FE four-cylinder and the 3.4L 5VZ-FE V6, 2WD and 4WD, manual and automatic. Where a check only applies to one engine it says so.
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 front diff and transfer case oil to the factory spec | Shop on Amazon |
| Fluid transfer pump | Filling through the fill or check plug | Shop on Amazon |
| Digital multimeter | Voltage, ground and continuity checks | Shop on Amazon |
| 1/2" drive click torque wrench | Tightening suspension and driveline bolts to spec | Shop on Amazon |
The same problem on other Toyotas
- 2nd Gen Tacoma (2005–2015): 4WD won't engage, 4WD light flashing, or grinding in four-wheel drive
- 1st Gen Tacoma (1995.5–2004): 4WD won't engage or front axle doesn't seem to drive
- 4th Gen 4Runner (2003–2009): 4WD won't engage, front axle stuck or binding
- FJ Cruiser (2007–2014): 4WD will not engage, or the A-TRAC / VSC lights come on
Other drivetrain problems on the 3rd Gen 4Runner
More 3rd Gen 4Runner problems
- Clunk, knock or loose feel in the front end over bumps (Steering & Suspension)
- Shimmy, vibration or steering wander at highway speed (Steering & Suspension)
- Frame rust, rotten rocker panels or rusty underbody (Frame & Body)
- Engine overheating or temperature gauge climbing (Cooling)
- Pink or milky transmission fluid, or coolant in the transmission (Transmission)
- 5VZ-FE timing belt service: when is it due and how do I tell? (Engine)
All 16 3rd Gen 4Runner 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.