Common problems · 2013–15
G63 AMG 6x6 problems: 8 things to check
The problems owners and specialists flag most on the Mercedes-Benz G 63 AMG 6×6, the repairs they end up doing and what those cost, plus the years and recalls to watch. Sourced, not scraped.
G63 AMG 6x6 problems to check before you buy
- Factory truck or conversion?Aftermarket 6×6 conversions of ordinary G 550s, G 63s and G 65s exist and have sold on Bring a Trailer. Factory trucks sold there carry chassis numbers such as WDB4632721X…, plus overhead tyre-pressure controls and a VDO auxiliary fuel gauge. Ask for Mercedes build paperwork.
- US paperworkIn the US, check the NHTSA Show or Display exemption letter, the EPA conversion label and whether NHTSA has approved the transfer. A clean title alone doesn't make it legal to drive.
- Tyre inflation systemRun the pressures down and back up. Mercedes quotes under 20 seconds from 0.5 to 1.8 bar. Slow inflation or a pressure drop overnight points to rotary seals or lines; one Bring a Trailer truck had its CTIS seals and lines replaced.
- Portal hubs and sealsLook for gear oil at each of the six hubs and the pinion seals. Ask when the hubs, differentials and transfer case were last serviced. Bring a Trailer service records mention a replaced centre-axle planetary gear and pinion seal on one truck.
- All five lockersEngage all three stages and confirm every indicator. The locks are supposed to engage quickly, even in high range, and slow or partial engagement needs investigating.
- The G 63 engine underneathIt's an M157, so check the same things as on a G 63: oil consumption, coolant at the turbo lines, oil in the cam-magnet connectors and plug or coil misfires.
- Modifications and tunesBrabus, Weistec and other tuners have modified these trucks. Find out exactly what has changed, including engine, exhaust, suspension and tyre size, and whether the original parts come with the truck.
- Tyre age37-inch beadlock tyres in the right size are a special order. Read the date codes; a low-mileage truck can easily have tyres ten years old.
The repairs G63 AMG 6x6 owners end up doing
| REPAIR | SYMPTOMS | DIFFICULTY | TIME | COST |
|---|---|---|---|---|
| Tyre-inflation (CTIS) leaks | Slow inflation, one axle losing pressure overnight, the compressor running a long time, hissing at a hub. | 3 / 5 | Specialist job | Specialist quote |
| Portal hub & differential oil service | No record of hub service, weeping at a hub, metal on a drain plug magnet. | 2 / 5 | Half a day | Parts plus labor |
| Differential locks slow or not engaging | A locker indicator that flashes or stays dark, or a lock that engages slowly or drops out. | 3 / 5 | An afternoon to diagnose | Diagnosis-dependent |
| Turbo coolant lines (M157) | Coolant loss, coolant crust near the turbos, low-coolant warning. | 4 / 5 | A day or more | Parts plus labor |
| Plugs, coils & cam magnets (M157) | Misfires, rough idle, oil in the cam-adjuster magnet connectors. | 2 / 5 | 3–4 hours | Parts plus labor |
| 7G-TRONIC fluid & filter | Harsh or delayed shifts, or no record of the job. | 2 / 5 | 2–3 hours | Parts plus labor |
| Steering damper & front-end play | Wander, shimmy on the big tyres, clunks over bumps. | 2 / 5 | ≈ 2 hours | Parts plus labor |
| Beadlock wheel & tyre service | Slow leaks at the bead ring, old tyres, mismatched sizes after a replacement. | 2 / 5 | An afternoon | Tyres plus labor |
Each repair links to a step-by-step guide with tools, part numbers and where to buy the parts.
Take the printable G63 AMG 6x6 inspection checklist: every check on this page plus the model-specific ones, on one sheet. Get the checklist →
Sourced from owners, specialists and factory documents; full sources are on the G63 AMG 6x6 guide. Verify torque figures and procedures against the factory service manual (disclaimer).