The whiffle tree is the threaded rod mounted in the bottom of the pop up. A draw bar runs up and down the rod and pulls or releases the cables. There were two types of whiffle trees used. Ball bearing and plastic delrin nut. This style of ball bearing tree is more commonly found on larger box sized units, and units with power lifts. How to install this system Video available Direct compatibility Fits 1996 through early 2000 Grand Tour Series. Fits 1999 Grand Tour Elite series with clutch release crank and sprocket. Fits 2000 Grand Tour and Grand Tour Elite series 12 foot box only with clutch release crank and sprocket. Measures 34-7/8 inches in overall length. 25-1/2 inches between the pre set stops. This stop measurement is found from the inside of each stop. Enclosed ball bearing design. Coarse thread. Draw bar travel distance = 25-1/2 inches. 1 inch of draw bar travel = 1.71 inches of lift height. Maintenance Tip : Liberally grease the screw with a lithium grease. Here is a link to a do it yourself maintenance video. The draw bar runs on a internal ball bearing system. Do not run the draw bar off of the whiffle tree or all the bearing will escape ruining the assembly. Running the draw bar over a hole in a removed stop can also result in failure. Part number 4720G5201
