Ampli Torc hub Dimensions for sprag assy

The spring and roller type uses ramps built into the outside hub and is operated by the springs pushing the rollers up the ramps to grab the inner hub. The sprag type is completely round on both the inside and outside surfaces where the sprag runs and is operated by small brass pieces that run on the inner hub causing the inner sprag cage to turn with respect to the outer cage thus standing up the sprags. The sprags are shaped like a dogbone and are longer that the distance between the inner and outer hubs and when stood up grab both surfaces.

On both type of torques there are usually small surfaces that are not worn that can be measured for reference. If your torque is the sprag type, it is likely that the outer surface where the sprag runs is also damaged since the sprag grabs both surfaces. The early style with the springs and rollers usually have indentations worn into the ramps (on the outer hub) and will need to be smoothed as well or the rollers will stop in the indentation and not work properly.

John

In general, Sprag Clutches are able to transmit greater torques, within given overall dimensions, than other types of free-wheel device.

There are 3 basic applications for a sprag clutch: overrunning; indexing; backstopping

Bob: Give Welters a call or Wilbert Kerchner or even Wendel Everett a call because I am sure one of them has one alreadly out. If you need phone numbers email me it is open. The only trouble is with that is there will be some wear on those too. But all the same they maybe able to just sell you a used one. I have one out now I bought in a pile and have no idea what tractor it is for. I can tell you it is not a Jetstar.