REDLINE ALLEYMercedes Benz G-Class W463 buying guide
1990 to 2018. A W463 suits a buyer who wants an old school, hand built off roader with luxury trim and will pay for a thorough rust and driveline check first.
Big jobs
- Body corrosion. Rust is the first thing to check on a W463. PistonHeads names the area round the windscreen, the sills, the door hinges and handles, the tailgate and round the rear lights.
- Three differential locks and transfer case. Differentials that are rarely used can stick, so all three locks need testing. The transfer case control module on pre 2004 trucks has a poor reputation.
- Automatic gearbox and diesel turbo. On the 7G-Tronic, broken internal speed sensors can cause random shifts or no shifts. Diesel turbos can leak oil, which PistonHeads calls an expensive repair.
- G 63 cylinder bore scoring. Cylinder bore scoring is reported on the 5.5 twin turbo M157, most often on tuned trucks, and the right grade of oil matters.
Workshop jobs
- Oil and coolant leaks. Petrol engines can leak oil from the oil cooler and filter housing gaskets and coolant from the thermostat gasket. On the G 63 the valve covers, turbos and sump gasket can weep oil, and coolant leaks can start at about 100,000 miles.
- Propshaft and driveline shudder. A heavy shudder on the move points to propshaft failure.
- Steering box, springs and wheel bearings. Steering boxes are often damp with fluid, rear springs break on trucks used off road, and worn wheel bearings and poor alignment are common. On the G 63 dried out power steering hoses can leak.
- Interior electrics, headliner and sunroof. Window regulators and air conditioning fail, sun visors fail and are costly to fix, the headliner can sag, and a poorly sealed sunroof lets water in at the front of the headliner.
Questions for the seller
- Which engine is it: G 500, G 55, G 63 or a diesel?
- Have all three diff locks been used and tested recently?
- Has any rust repair been done round the windscreen, sills or hinges?
- When were the diff, transfer case and gearbox fluids last changed?
- If it is a G 63, has the engine been tuned?
Sources
Researched 2026-11-05. General guidance from owner and specialist sources. Check the specific car with an independent inspection.