Upgrade Your X-Maxx to XRT-Spec
How to Take your X-Maxx to the Next Level of Performance
For nearly 25 years, the Maxx® name has been synonymous with power, speed, and durability. Like T-Maxx® and E-Maxx® before it, X-Maxx® ushered in a new paradigm of RC technology and toughness. Over the years, Traxxas enhanced X-Maxx with new power and performance upgrades, taking the X-Maxx experience to the next level. XRT® builds upon this X-Truck™ heritage with even more performance and durability improvements. What you may not realize is that most of these upgrades are backwards compatible with X-Maxx.

Being the newest X-Truck has its advantages. Traxxas took everything learned from X-Maxx and built an even tougher truck in XRT. Traxxas engineers spent a lot of time ensuring these upgrades would also fit X-Maxx.
XRT shares DNA with X-Maxx so naturally many parts are interchangeable. This makes it easy to find replacements at your local hobby store no matter which model you have. Of course XRT is much more than just a re-bodied X-Maxx so it has its own unique driving style, but radical toughness is one thing both trucks share. In this article you’ll learn which upgraded XRT parts are transferrable and why you want to get them. Let’s take a look!
Suspension
XRT’s speed and agility would be impressive in a 1/10 scale truck, never mind an 8s monster truck weighing nearly 24 pounds. Traxxas engineers knew that level of performance required the toughest design they had ever created. This translated into bigger, beefier parts made from Traxxas’ strongest composite material.
Steering and Caster Blocks
Steering blocks and caster blocks (C-hubs) are the heart of the X-Truck suspension. In a 4WD monster truck, they pull double duty, controlling steering and putting all that 8s power to the pavement. X-Maxx’s components are definitely top-notch, but XRT takes it to the next level. XRT’s steering and caster blocks are beefed up with more material and strengthened with a new reinforced design and large heavy-duty bearings. When you turn up the dial to “full send,” you want as much strength as you can get in these critical areas. Note: newer X-Maxx models feature revised steering blocks with upgraded 20x32x7 mm inner bearings, but these revised steering blocks are still not as tough as XRT’s.
Steering blocks and caster blocks (C-hubs) are the heart of the X-Truck suspension. In a 4WD monster truck, they pull double duty, controlling steering and putting all that 8s power to the pavement. X-Maxx’s components are definitely top-notch, but XRT takes it to the next level. XRT’s steering and caster blocks are beefed up with more material and strengthened with a new reinforced design and large heavy-duty bearings. When you turn up the dial to “full send,” you want as much strength as you can get in these critical areas. Note: newer X-Maxx models feature revised steering blocks with upgraded 20x32x7 mm inner bearings, but these revised steering blocks are still not as tough as XRT’s.

Owners with older X-Maxxes can purchase the 7836X upgrade kit that includes both the steering & caster blocks, along with larger bearings.
Rear Axle Carriers
There can be no weak links or shortcuts when building a 60+ monster truck with the size and performance of XRT. That’s why Traxxas engineers redesigned XRT’s rear axle carriers with the same attention to detail as the steering and caster blocks. Extra material and improved reinforcements make these the toughest axle carriers in the Traxxas lineup. Best of all, they’re fully compatible with X-Maxx. Note: newer X-Maxx models feature revised axle carriers with upgraded 20x32x7 mm inner bearings, but XRT’s are still stronger.
There can be no weak links or shortcuts when building a 60+ monster truck with the size and performance of XRT. That’s why Traxxas engineers redesigned XRT’s rear axle carriers with the same attention to detail as the steering and caster blocks. Extra material and improved reinforcements make these the toughest axle carriers in the Traxxas lineup. Best of all, they’re fully compatible with X-Maxx. Note: newer X-Maxx models feature revised axle carriers with upgraded 20x32x7 mm inner bearings, but XRT’s are still stronger.

Newer X-Maxx owners can upgrade their trucks just by adding the 7852 rear axle carriers and swapping over their existing bearings.

Owners with older X-Maxxes can purchase the 7852X upgrade kit that includes both the revised rear axle carriers and the larger bearings.
Wheels & Tires
XRT’s Gravix® race tires are a revolutionary hybrid design with unstoppable traction on any surface. Densely packed biting edges deliver outstanding grip and quieter running than X-Maxx’s monster truck tires. A lower sidewall offers improved turn-in response and handling for X-Maxx owners seeking a more refined driving experience. XRT’s high-tech 3.8″ race wheels are the same size as X-Maxx, but designed for extra-tight grip on the tire to cope with XRT’s higher speeds. They use the same huge 24 mm splined hub and 17 mm locknut for maximum grip on the aluminum hub. Gravix tires and XRT wheels are also available separately as parts 7873 and 7874, respectively.

XRT wheels and tires 7877 are available as pre-assembled sets for quick and easy installation.
Bonus Upgrades
Extreme Heavy-Duty Drive Cups
Machined from high-grade steel, 7754R drive cups are the last word in toughness for XRT or X-Maxx. These accessory drive cups are heat-treated for maximum strength to resist rounding from the dogbones on the 7750X steel constant-velocity driveshafts. Early 6s X-Maxx models may require an upgrade to the 7750X driveshafts and associated parts, but for most trucks this is a simple 5-minute drop-in upgrade.
Machined from high-grade steel, 7754R drive cups are the last word in toughness for XRT or X-Maxx. These accessory drive cups are heat-treated for maximum strength to resist rounding from the dogbones on the 7750X steel constant-velocity driveshafts. Early 6s X-Maxx models may require an upgrade to the 7750X driveshafts and associated parts, but for most trucks this is a simple 5-minute drop-in upgrade.

Hardened steel drive cups transfer power from the differential to the driveshafts. The special heat-treating makes them extra strong and resistant to rounding no matter how hard you send it.
Overdrive Gears
This next upgrade is a nod to all the speed demons out there chasing ludicrous speed with their X-Trucks. As any top speed enthusiast will tell you, there’s a limit to how much gear you can put on any given vehicle. You want the largest pinion and smallest spur gear you can fit, but sometimes clearance becomes an issue. That’s where the 7886 Overdrive Gear Set comes in. The overdrive gear set replaces the standard transmission gears with a 24-tooth input gear and 47-tooth output gear, effectively adding 5-6 teeth to the pinion gear size. Before you start thinking about triple-digit speeds, make sure you understand the warning on the product page. These gears are serious business and not intended for the stock power system.
This next upgrade is a nod to all the speed demons out there chasing ludicrous speed with their X-Trucks. As any top speed enthusiast will tell you, there’s a limit to how much gear you can put on any given vehicle. You want the largest pinion and smallest spur gear you can fit, but sometimes clearance becomes an issue. That’s where the 7886 Overdrive Gear Set comes in. The overdrive gear set replaces the standard transmission gears with a 24-tooth input gear and 47-tooth output gear, effectively adding 5-6 teeth to the pinion gear size. Before you start thinking about triple-digit speeds, make sure you understand the warning on the product page. These gears are serious business and not intended for the stock power system.

The Overdrive Gear Set effectively adds 5-6 teeth to your pinion gear size to get around clearance issues, but it's not for the faint of heart! This is a serious performance upgrade for experts only!
Whether you’re looking to change your X-Maxx’s driving characteristics or just add additional toughness, upgraded XRT parts are just the ticket. They’re quick and easy to install with a guaranteed factory-fit.