How One DIYer Built a Whisper-Quiet, Torque-Monster Rockcrawler

Grant 117 wasn’t planning on building the world’s first electric rock crawler when he started this project. He just wanted to ditch the noise, heat, and exhaust fumes that come with wheeling a supercharged V6 in a tube buggy. What he ended up creating was something that’s got the electric vehicle community and rock crawlers talking - a 3,500-pound beast running on 42" Trepadors that can climb anything and do it whisper quiet.

The build started with a forum post asking if his conversion plan would work. Grant had 1 ton axles, those massive sticky tires, and a Warp9 motor with a Curtis 1231 controller on the way. What he didn’t have was experience with electric conversions, but that didn’t stop him from pulling the ICE and diving headfirst into uncharted territory.

The motor showed up damaged from shipping, but a few “love taps” freed up the locked armature. Grant fabricated his own adapter plates from quarter-inch steel and built a custom coupler to mate the Warp9 to his T4 manual transmission. The whole drivetrain setup uses a 4:1 transfer case with 4.10 axle gears, giving him the low-end grunt needed for technical crawling.

Battery selection became the real challenge. Grant initially planned to run 12 volt AGM batteries but quickly realized he needed something with more energy density. After advice from forum members, he switched to a salvaged Chevy Volt pack - a decision that transformed the build. The Volt pack gave him the power density he needed while keeping weight reasonable for a rock crawler.

Configuring the Volt pack proved tricky. The pack has nine modules total - seven 12-cell modules at 48 volts nominal and two 6-cell modules at 24 volts. Grant ended up running three 48 volt modules plus one 24 volt module in series for a 168 volt pack. He built a second identical pack and switches between them using forklift-style connectors, giving him about 14 kWh total capacity.

The first trail runs revealed both the potential and limitations of electric rock crawling. The instant torque was incredible - no more waiting for the engine to build revs or worrying about stalling on steep climbs. The motor stayed cool even under heavy load, thanks to a 12 volt cooling fan. But range was the limiting factor, with about four hours of wheeling time per charge.

Grant didn’t stop there. He upgraded from the Curtis 1231 to a Zilla 1K controller, cranking up the power to 600 amps at 160 volts. The difference was immediately noticeable - more torque, better throttle response, and the ability to spin those 120 lb tires at will.

The buggy sits on a Goat/Jesse Haines chassis with Dana 60 front and Dana 70 rear axles. Full hydraulic steering handles the load from those 42" BFG Krawlers, while 14" ORI struts and PRP suspension seats keep things comfortable during long trail days. The whole package weighs in at 3,500 pounds - not light, but reasonable for a full-size crawler.

What makes this build special isn’t just the electric drivetrain - it’s proving that electric can work in the most demanding off-road conditions. Grant’s getting full-day range with his dual-pack setup, and the performance advantages are real. No more carbon monoxide headaches, no engine heat cooking the driver, and torque delivery that makes technical climbs easier.

The build cost around $2,000 for the Volt pack plus controller and motor costs, making it competitive with a built ICE setup. Grant wheels at parks throughout Kentucky, Tennessee, and Alabama, with his home base being Interlake in Southern Indiana. The electric crawler has handled everything from technical ledges to WOT hill climbs without breaking a sweat.

Other builders are taking notice. The instant torque, reduced maintenance, and environmental benefits make electric power appealing for off-road use.

This build proves that electric power isn’t just for street cars and daily drivers. When you need maximum torque at zero RPM and want to wheel all day without the noise and fumes, electric might just be the future of rock crawling. Grant’s tube buggy is leading the charge, one technical climb at a time.