Hey everyone. I need some input from those of you experienced with replacing tach cables.

This last weekend I had my tach cable shear. It failed about an inch from the end that goes to the accessory case. When it failed, it appears that it ate whatever o-ring there was that kept the lubricating fluid in the sleeve. I've tried to find the part number for that o-ring, as well as an exploded view of the area from the back of the Cessna original tach to the accessory case, but have had no luck. Can anyone shed some light on this for me? Does anyone know if such a diagram exists, or have a part number for the o-ring?

Also, while detaching the cable from the back of the tach, my mechanic dropped what he thinks was a Teflon washer. Can anyone tell me 1) is that supposed to be there and 2) if so, a part number? The new assembly comes with no such washer.

The tach turns freely and when tested with a drill hooked to the old cable, it appears to be working fine. Why it sheared is unknown. The plan is to replace the cable. I picked it up today. If that doesn't fix it, I've got a line on a good deal on a digital tach and will go that route.

Feel free to post any advice or recommendation. Thanks for the help!

Cory

My original (& Stuart Warner replacement) both ate the cables. Bought a digi tach & after getting used to it I do like it better. Bit of hassle building the wiring harness & getting it set up but nice having pinpoint accuracy for leaning & mag checks.