TxDieselKid,
Yes there can, and that is what I have always stressed. Competition is good. Anyone that knows me knows that I do not recommend our clutches for sled pulling, they are not designed for that. If you need a sled pulling clutch you should go with a double disc unit from other clutch suppliers and I will recommend a few different places to anyone that asks. Now, if someone says my clutch can't handle over 400 hp and haul heavy loads then I will step in and say... Yes it will. The reason I’m concerned about transmission wear with the double disk or ridged style of disks, is not a tactic to sell our product. Come on... we are a clutch company. If I felt there was not any concern I would build them and sell them. I only state this because I have first hand experience. I tried the ridged style of disks in the diesel transmissions in the mid '90s and I had to replace a few transmissions due to internal damage. The harder I tried to disprove it being a clutch design problem, the worse I looked. I then went to a dampened, or spring loaded, style of clutch that was not designed for diesels, the difference here being a floating hub center, and I still had idle clattle with clatter in 4th and 5th gear driving on the highway. I have heard a lot of the people that have the double disk unit say that the rattle comes from the center plate and, yes, that is true when the clutch is depressed. The center plate is freed at this time allowing it to flop around a little causing the clatter. But think about it... when the clutch pedal is not depressed everything is squeezed together ready to drive. As Gene has stated, sitting still he may need to shut the vehicle off to hear someone talking, or if he is driving down the road and the clatter gets too loud he just needs to roll the windows up which tells us that something is making noise. It is NOT the clutch making the noise. A diesel engine spikes at the crank unlike a gas engine. If you fasten the input shaft with ridged disks to the spiking crank/flywheel then you are also spiking the input shaft. That is why they make the disk hubs free floating in a diesel, thus, allowing the input shaft to sit still while the flywheel is spiking. The noise, or clatter, that is heard in neutral or driving down the road, when your foot is off the clutch pedal, is NOT the clutch itself. That kind of knocking cannot be good on your truck, can it?
If you are planning on sled pulling then you are not really too concerned about damage to the truck and a double disk is perfect for you. Now this is my opinion, and my opinion could be completely wrong. This post was not to disprove or compare anything, this is only what I experienced. And trust me, when someone asks me where to get a clutch for sled pulling I will direct them to the people I know that carry double disk clutches. When I figure out how to put a floating hub in a unsprung disc I will sell a double disc unit as well because YES they can hold more power.
Peter