? Proper use of Feeler Gauge

This is in regard to checking the proper backlash in the power takeoff between the bevel gear and bevel pinoin/drive shaft. The manual says to use a feeler gauge to check for correct backlash (clearance)between the bevel and pinion gears. Recommend backlash is .006 to .010. When checking should the blade of the gauge go through the entire depth of the gear cogs? I have never done this before and want to be sure I have the proper backlash. There seems to be more clearance at the top. As the gauge goes further into the space between the cogs, the clearance is less. What is the proper procedure?

Thank you,
Ken Reese
e-mail: kwreese@aol.com

The depth of the pinion in relationship to the ring gear will have some effect on how the gears mesh and whether they mesh near the toe or heel all of this will change the actual gap, but the difference between the two gaps should give a useable reading. It has been a long time since I done it this way, so I hope my memory is accurate. We would also use white lead to coat the surface of the teeth and by turning the gears the contact pattern would be marked on the painted surface to allow you to judge if the pinion depth shims or adjustment needed to be changed.

Hope this help Tom R.