As a new m998 owner and someone getting into off roading, I don't see anything that he is doing wrong. Clearly just a highlight of my inexperience. Was it just that he was using oversized tires? Can someone please give me some insight so that I don't make the same mistake?
I didn't watch the video in any great length to make for anything like a thorough analysis, but the two things I've heard people gripe about the most in response is the tire size is too large, causing them to strike the hood at times (and this will also throw off your speedometer), and what appears to be the lack of usage of brake-throttle-modulation (BTM). BTM is tricky for someone just learning, but it proves itself as necessary for the style of differentials used in the HMMWV (Torsen Differentials).
When the transfer case is placed into either of its "locked" positions, this only locks the transfer case to give 50% power to the front and 50% power to rear. The front and rear both have their own torsen differential, allowing each pair of wheels to rotate at different speeds-not a slip limiter, but as a torque biaser (tries to deliver more torque to the wheel with the most traction); however, if the speed of the wheel with traction loss goes significantly beyond that of the wheel with traction, the torque bias will be lost and all the power will dump into the free-spinning wheel. Therefor, we apply the brake
prior to losing traction in order to prevent this free-spinning action. I don't personally have the wheeling experience to back this up, but I believe the preferred methodology would be to firmly press the brake, apply throttle to an appropriate amount, and then gradually release the brake while maintaining the throttle until you're rolling with just enough drag to prevent the wheels from spinning excessively.
An important caveat-which is what was observed in this video-is to
never apply the brake to
stop a wheel that is already free-spinning. A 37" HMMWV wheel with a runflat installed weights around 150 lbs. Once spinning fast, there is a tremendous amount of rotational force in that wheel; yet, our brakes have plenty of power to stop these. Since our brakes are inboard, that means all of the stress of stopping that force falls into the geared hub and the CV axle...the geared hub can take it. The CV axle cannot. That's almost certainly what caused his CV axle to break.
