I would be excited if their testing procedure could give a tangible rating on a used coupler, like several torque factors in in-lbs or even just a performance rating from one to ten. Just knowing it still works doesn't pass judgement on how long it will continue to work. Mileage doesn't say much about a VC's status with some Eagles left in all wheel drive and others driven routinely in 2wd.
Specifically I wouldn't trust their testing procedure without a description of how they compensated for a lower initial viscosity. That would effect how long it would take for the fluid to reach operating temperature. Worn fluid may still reach a necessary torque value when actively spun, but would not be as responsive as new fluid. In normal operation the two differential outputs are usually married together without VC assistance, so it would not have the relative motion to build up heat with.
I'm imagining a device that clamps the housing still and measures the applied torque necessary to keep it still while the center turns a known RPM. I would expect an initial torque value for the fluid cold, a normalized torque value for the fluid after a standardized number of applied rotations, and a concluding torque value once the fluid reaches an optimal temperature. All three are necessary to quantify how worn a unit is and how responsive it will be relative to a new unit.
I would love to be able to strip all my VCs out and send them to a testing location if I can get a formal report for each one that indicates exactly how worn it really is. The new old stock units are expensive enough to make that worthwhile.
Topic: Rebuilt transfer case options with viscous coupling discussion. (Read 21977 times)