YHR, feel free to post here. I tried the metal gears. They are great and get rid of the slip-clutch. Mine worked great on flat ground but started slipping again when I hit resistance. The plastic gears in these things arn't bad. It's the cheap, thin wall plastic they use to support the shafts. It will quickly wear and the axles get real sloppy, causing slippage. There are no bushings in this thing. I wish you luck with them but the whole setup will be prone to problems unless you bush the shafts. That's why I'm going through all the gymnastics to put the HL's in.