I have a 93 with a 5 speed manual trans. with 81000 miles on it. At around 3000 miles my clutch began to chatter when trying to move my 5th wheel trailer in revearse. It has gotten worse over time, but i have no slippage problems, just a bad jerking when trying to back up the trl. The clutch will just not slip to ease back slowly and it is starting this in the forward gears on take off. I am preparing to replace the clutch and am wondering which type should I replace it with, I do mostly towing a 8000 pound trailer. I have not modified the engine, it is as it came from the factory.