[Rob]

To add to what Jeff said...

I think the Toughboxes are louder than the 2005/2006 KOP transmissions because of a few design differences.

First, I think the Lexan side plate "resonates" a bit and just makes it sound louder even if the internal conditions are the same as the old boxes.

Second, the internal conditions are different from the 2005/2006 KOP boxes. The older ones used thicker gears and had spacers to locate the gears on the shafts. The Toughbox has a thinner gear face, and the spring pin that locates the gear on the shaft allows it to "flop" around a bit which adds more of a ringing sound.

Do not trivialize grinding sounds however...I would open the box, look for burrs or misalignment anywhere, grease it with lithium grease and reassemble.

A good way to break in your boxes is to run them off of a bench top power supply that shows current draw. Look at the free current of your motors and if the setup you have draws significantly more that you expect, then you should break down and rebuild the transmission.

The lithium grease is also thick and can help dampen sound. We greased our gearboxes and ran them on the bench for about 20 minutes each to break them in. They sounded alot better after the break in period, but are still louder than the 2005/2006 KOP transmission or the AM 1 speeds we used last year.

Remember, it is really worth taking your time to get it right here...your drivetrain will be the most critical system on your machine!

Good Luck,

RAZ