Checks, in order
- Hammer test the frameTap the rails behind the front wheels, inside the C-channel, near the catalytic converters and around the rear axle. Solid steel rings; flakes or a thud mean thin metal. Owners in salt states have found perforation under 100,000 miles.easy $ · under about $50
- Ball joint boots and playWith the wheel off the ground and a pry bar under the tire, look for vertical play at the lower joint. A torn or missing boot means replace it now, before it wears.easy $ · under about $50
- Replace with OEMToyota lower ball joints or complete lower arms are the common recommendation on IH8MUD after repeated reports of aftermarket joints corroding. It is a pressed joint; most owners have a shop do it.hard $$ · about $50 to $500
- Treat the frameWire brush, rust converter and a yearly lanolin or wax coating in salt states. Perforation near suspension mounts is a fabrication repair or a reason not to buy.medium $$ · about $50 to $500
Applies to: Lexus GX 470, 2003 to 2009, with the 4.7L 2UZ-FE V8 (timing belt) and the A750F 5-speed automatic. Every US GX 470 has rear air suspension; KDSS was optional from 2004. It shares its chassis with the 4th gen 4Runner and 120 Series Prado, so many 4Runner parts and procedures apply.
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 |
|---|---|---|
| Rust converter | Treating surface rust before sealing it | Shop on Amazon |
| Lanolin undercoating | Protecting the frame and underbody from salt | Shop on Amazon |
| Wire wheel set for a drill | Removing loose scale before treatment | Shop on Amazon |
| Pry bar set | Checking ball joints, bushings and tie rod ends for play | Shop on Amazon |
More Lexus GX 470 problems
- Rear end sags overnight or leans, compressor runs long or never, suspension warning light (Steering & Suspension)
- Timing belt due or history unknown, coolant weep at the front of the engine (Engine)
- Ticking from the engine on cold start that fades as it warms (Engine)
- VSC TRAC and VSC OFF lights on, with or without a check engine light (Body & Electrical)
- Dashboard cracked, sticky or shiny and soft in the heat (Body & Electrical)
- Rear swing-out door will not open from outside or inside, or will not latch (Body & Electrical)
All 11 Lexus GX 470 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.