I just couldn't leave well enough alone. My Pershing was running perfectly, and then I had to mess with it. I had ordered metal gearboxes for my Tiger, which I no longer needed, so I decided to put the metal gears into the Pershing gearboxes. After that major pain was over, I had also received a set of metal sprockets for the Pershing. It was hell trying to get them on. There was no amount of "pressing" to get them on, they had to be "tapped" on with a hammer. After wrestling with the tank for about 2 hours, I got it back together and tried to run it. The tracks would barely move! (I attributed most of this to the metal gears needing to "break-in") I tried to run it for a while to break the gears in, but the strain kept making my Scorpion esc go into overload protection. The gears must be in too much of a bind, and I can't believe how hard it was to get the sprockets on. I consider myself a decent mechanic and tinkerer, and have been around cars, dirt bikes, and r/c cars for years, but man, I feel like a boob trying to work on these HL tanks. So far, I'm 2 for 2, ruining both of them. I'm beginning to think this hobby is not for me. At first I thought, "Hmmm.. .R/C tanks are slow and couldn't break anything, and shouldn't be too hard to work on." I was definately wrong.