Magnum 272 undeniably sounds tough. And, while this Traxxas transmission design has certainly proven to be durable and has also received some substantial upgrades over the years (metal gears, bearings, slipper pads), it is still not without some flaws. The two most noteworthy issues are the hole in the bottom of the transmission case and the plastic motor mount. RPM has the solution for both those problems. For this review, I installed mine in a Stampede. Over the years, I’ve owned a number of Traxxas vehicles and the Stampede is one of my favorites–not just in the Traxxas lineup, but in RC. It’s just a fun platform, but the Stampede isn’t the only Traxxas vehicle to use the Magnum 272 transmission. The Rustler, Bandit and 2WD Slash all use the Magnum 272. So, when RPM came out with this improved gearbox case, it released a hop-up that can improve a wide range of vehicles, not just one.
As mentioned, the RPM Gearbox Housing fits the 2WD Slash, Bandit and electric versions of the Rustler and Stampede. All of the internal gears, bearings and shims from the original transmission are used, so you will need a Magnum 272 transmission to convert. The alignment of the gears stays the same. This housing doesn’t provide either a more standup or letdown arrangement of the gears. What is does provide is a 3 mm thick 6061 T6 aluminum motor plate. This is simply a huge improvement. The stock plastic motor mount was a problem. Not only does the aluminum hold motor screws better, so that you don’t loose gear mesh and strip out gears, but it won’t distort when the motor screws are tightened down. Also, because it’s aluminum, it will dissipate heat far better than stock.
To allow for clearance for the differential, the original transmission had a hole in the bottom. Even though the skid plate on a Stampede or Slash or the chassis on a Rustler or Bandit covers the hole and even though it’s common to cover the hole with electrical tape, it simply let’s dirt in. The RPM housing fixes this.
An unexpected-but-welcome feature is the fact that RPM went with separate, nonintegrated suspension arm mounts. This allows for either 0º or 3º of rear toe.
As you’d expect, RPM molded this gearbox out of its durable blend of nylons. While anything can be broken, RPM’s material is as close to indestructible as you’ll find RC. It’s available in black, blue and green.
TESTING & FINAL ASSESSMENT
I have a Traxxas Grave Digger (now discontinued) version of the Stampede that pretty much has the full RPM treatment. It is equipped with a Castle Creations 5700 kV that I run with either a 3S or 2S MaxAmps.com LiPo. Yes, this setup is complete overkill for a 2WD Stampede, but if you’re going to test durability, this is the way to do it.
Installation was a breeze. RPM has detailed instructions and everything fit together perfectly. I also used RPM Stampede rear arms, and when combined with the gearbox, I saw neither binding or slop. The fit was perfect, which isn’t always the case with molded parts.
Testing did not consist of one run. I can’t tell you how many packs have been put through this transmission, but it’s been a lot over the last few years. It’s been run on dirt, in sand, over gravel, through mud. If it was going to fail, it would have by now. Because I’ve combined the transmission with an RPM gear cover (which solves the hole in the gear cover problem), I’ve had to perform zero maintenance on the drivetrain. The motor has never budged and the transmission has shown no signs that a rebuild will be needed in the near future–and it’s been years. So, unless you’re racing in some spec class that doesn’t allow it, I highly recommend the RPM Gearbox Housing.