170K Miles Later: What’s Broken on My Lexus GX460
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Owning a Lexus GX460 has been one of the best vehicle experiences I’ve ever had. It’s been my overland rig, daily driver, road trip companion, and weekend warrior all rolled into one. But after 170,000 miles of adventures, it’s fair to say the truck has had its share of issues.
I wanted to break everything down into categories so anyone considering a GX460—or running one into high mileage—knows what to expect. I’ll also share which issues are common to the platform and which ones were self-inflicted from the way I’ve used (and occasionally abused) this rig.
Engine Issues
The GX460 is powered by Toyota’s legendary 4.6L V8(1UR-FE), so the engine itself has been rock-solid. Most of the problems have been age- and mileage-related:
Water Pump – Mine started leaking around 120K miles, so I replaced it along with the drive belt, tensioner, and idler pulley at the same time. This is common with almost any engine with higher mileage, but it's worth noting and keeping an eye on.
Valley Plate Coolant Leak – A fairly common issue that popped up at about 130K miles. This happens due to the sealant breaking down in the valley of the engine. The coolant then leaks and builds up in the valley. Inevitably leaking down the back of the engine and around the transmission bell housing. It's a tedious, labor-intensive job, but once it's done you don't have to worry about it again for quite a while.
Radiator – Developed a leak at about 165K miles and had to be replaced. This is common due to the design of the factory radiator. Having plastic end tanks; the radiator will split due to thousands of cycles of heating and cooling. Once it leaks, I highly recommend replacing it with an all aluminum radiator like this one from CSF Radiator. While you're doing the job, you should also replace the radiator hoses.
Ignition Coil – One ignition coil failed at around 150K miles, a quick and inexpensive fix. This isn't a common problem per se; more of a high mileage engine wear item.
Oil Leak / Seepage – I'm starting to notice leakage around the valve covers and spark plug tubes. Haven’t tackled it yet, but it’s on the to-do list. Again common on higher mileage engines.
Overall, nothing catastrophic—just typical wear-and-tear for a high-mileage Toyota V8.
Transmission
Here’s where I’ve had some performance degradation due to high mileage and heavy use case of my build.
Rough Shifts – It has started to feel a bit clunky. Something to keep an eye on for future degradation.
Valve Body Issue – There’s a known issue (with a TSB) on 2010–2011 GX460s. My 2012 shouldn’t have it, but it still shows some signs of odd shifting behavior.
Torque Converter Slipping – At this point, the transmission is just showing its age.
I haven’t repaired or replaced anything yet, but it’s on my radar as something that will likely need attention down the road. Based on forum and social media posts; it appears the transmissions are showing signs of failure over 150k miles. Mostly related to heavy use cases.
Suspension & Steering
This category has seen the most wear, but that’s also because of my overland setup and how I use the vehicle.
Lower Control Arms – Bushings are common to wear out. I believe a lot of this is due to the extra stress added from lift kits, larger tires, off-roading, and alignment specs to fit larger tires. Ball Joints are also known to wear out over time for the same reasons.
Upper Control Arms – Same story: bushings and ball joints will wear out.
KDSS Bushings – Notorious wear item on these, any vehicle with KDSS for that matter. Also, commonly overlooked. Due to the pressures and leverage of the large KDSS bars, there is a lot of stress on the KDSS bushings. I've found about every 20-30k miles I've had to replace at least a few of them.
Body Mount Bushings – Mine needed attention after years of rough trails and a heavy vehicle. PRO TIP: If you plan on installing after market bumpers and/or sliders: replace your body mount bushings before doing so. The factory bushings will wear out and collapse over time. Due to being a body of frame vehicle: when you go to install bumpers or sliders, you have to cut the factory bumpers or steps. Doing so before replacing bushings will make your gaps nice and neat. However; If you replace these bushings after installing bumpers/sliders, your gaps will now be MUCH bigger. Learn from my mistake!
Power Steering Rack & Tie Rods – Tie rods are a common wear item. However, the power steering rack gets quite a workout with the larger tires and heavy vehicle. Mine started to have chatter inside the rack when going down a trail. It gave a lot of unwanted feedback through the steering wheel.
Cam Tab Gussets / Reinforcement Plates – This is a common issue even on stock vehicles; even more so on modified/lifted vehicles. The alignment cam tabs from the factory are made of a very thin metal. These can very easily be bent over, causing a lot of alignment issues. I highly recommend purchasing cam tab gussets if you intend to leave the road. Your monthly maintenance budget will thank me.
Much of this is expected when you lift, wheel, and load down a GX460 for overland travel. This applies to any vehicle on the market.
Electrical
Alternator – Mine failed prematurely after I buried the truck in a mudhole and trashed the brushes.
Not a Lexus problem—this one’s on me. However, it's worth noting due to the mounting location of the alternator (down low on the passenger side), it is very easy to submerge the alternator which is not ideal.
Miscellaneous
These are smaller but worth mentioning:
Rear Barn Door Latch – It's common on older vehicles or vehicles used in salty areas. The pin inside the handle will rust and cause the handle to stick open. Not allowing you to close the barn door.
Rear Door Weather Stripping – A common GX quirk; the seal tends to fall off the door frame over time. I found using a small amount of 3M weatherstripping adhesive does wonders to keep them in the right place.
Takeaways
What I love about the GX460 is that even with 170K miles and plenty of hard use, the problems I’ve faced are mostly maintenance-related and fixable.
The engine is as reliable as they come.
The transmission is showing age but hasn’t failed.
Most of the suspension and steering wear comes from wheeling and carrying overland weight.
The small quirks (like the barn door latch and weather stripping) are easy fixes.
If you’re looking at buying a used GX460 for overlanding or long-term travel, don’t let the mileage scare you. Budget for maintenance and keep up with it, and the truck will keep going.
Watch the Video
I cover all of this in my latest YouTube video with more details and personal thoughts.
Final Thoughts
Every vehicle has its quirks, but the GX460 continues to impress me as a reliable, capable, and affordable platform for overlanding—even after 170K miles of trails, road trips, and adventures.
If you’ve got your own long-term GX stories or had similar (or totally different) experiences, drop a comment below or on the video. I’d love to hear how your rig is holding up!
