Symptoms
Rear sagging after sitting, a compressor running constantly, a height-control warning on the dash.
The fix, step by step
- Support the frame and axle, deflate and disconnect the air springs, remove them from their seats, and install a bolt-in coil conversion — Metal Tech 4x4 sells CNC-machined kits for 2003–2009 4Runners and GX 470s with rear airbags — then fit coil springs of the right rate for your load and disable the height-control system per the kit instructions.
Tools & part numbers
- Floor jack
- stands
- metric sockets
- Metal Tech 4x4 rear coil conversion kit
- coil springs
Where to buy the parts
Rear coil conversion kit, 2003–09 GX 470 & 4RunnerMetal Tech 4x4 ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Toyota 4Runner 4th Gen parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.