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Testing your Transfer case without using the Jack Test

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    Stumbled on this thread after finishing up some testing with my lathe. I figured I would share my results with you guys. I made a sort of pesduo-dyno out of my lathe in preparation for cutting viscous couplers open and making them rebuildable.

    I will admit I am absolutely surprised by the torque transfer these are capable of. A stock Subaru center differential viscous coupler is rated at 4 kgf-m @ 100 RPM. I interpolated my peak torque results and found they were around 16.5 kgf-m @ 100 RPM. Now I don't know if their ratings are at peak torque or a certain time after the test begins. The more colorful plot below shows how quickly the torque falls off.

    Also I had a really difficult time stopping the viscous coupler quickly at higher RPM. This caused the peak torques to be lower than perhaps they could be. The 220 RPM settings shows this slipping that occurred when I wasn't able to stop the viscous coupler quick enough.

    Curious if you guys have any feedback or tests you'd like to see? I am thinking the next batch will be at different temperatures of the coupler at the 110 RPM setting (closest to the 100 RPM rating of viscous couplers). For example soaking them at the following temps until thoroughly at these temps (0°F, 32°F, 45°F, and maybe closer to boiling temps) then running a test before they change temp. It'll take a couple of days but should be pretty cool :)