Re: Test for Posi-Traction
According to my IH manual (CTS-2568Q):
No precise methods of measuring limited slip differential performance are generally available in the field. A functioning unit can be determined by these relatively simple vehicle operational tests. [img]images/graemlins/givemebeer.gif[/img]
1. Place one wheel on good, dry pavement and the other on ice, mud, grease, etc.
2. Gradually open throttle to obtain maximum traction prior to "break-away." The ability to move the vehicle effectively will demonstrate proper performance.
3. If extremely slick surfaces such as ice or grease are used, some question may exist as to proper performance at step 2. In these extreme cases a properly performing limited slip differential will provide greater "pulling power" by lightly applying the parking brake.
So sayeth IH. Now since I just bought a Scout II which has a glovebox sticker claiming a rear diff. with a Powr-Lok, I too wanted to test for proper operation. After 30+ years even if the mechanism is visually confirmed who knows if it's working, right? So I tested mine in a similar fashion as above and I noticed that on a damp dirt road with the brake lightly engaged and the motor slightly revved, I would have power to both wheels as shown by the nice marks I left. I heard that jacking up one rear wheel and leaving the other in contact with the ground and manually trying to spin the tire and the inability to spin it would indicate that the mechanism is engaging. Seems to make sense since there are warnings about operating the vehicle in gear with only one tire elevated lest you run over someone. [img]images/graemlins/cussing.gif[/img]