TR4A: Tach help

["Richard G. Taylor" <rgt3000@one.net>]

I need to tap the wisdom of the list once again.

I was driving the 4A this AM (47 degreesF in Cincinnati) and my tach began
making a horrible screeching sound.  Any ideas on what would couse this?  I
disconnected the drive cable and the noise stopped so I am realitively sure
it is the tach.  Any advice and ideas would be appreciated.

TIA

Rick
TR4A CT57505