91 740 speedometer reading erratic

yosef7 · Post by **yosef7** » 25 Jun 2017, 07:05

Cannot find information on where to start fixing my erratic reading speedometer. any ideas?

93Regina · Post by **93Regina** » 25 Jun 2017, 15:57

yosef7 wrote: 25 Jun 2017, 07:05Cannot find information on where to start fixing my erratic reading speedometer.

admasters · Post by **admasters** » 14 Nov 2018, 10:49

Hello, the erratic speedo can be caused by two things. The first is a failing speedo gear (gotta look that up). The second is the speed sensors. My 92 has one speed sensor in the rear dif cover and those wires tend to get worn and break, check that. The 92 also has a sensor in each front wheel and they don't fail often. HOWEVER the tone ring behind the brake disk gets very rusty and loaded with dirt. Clean those up with a wire brush and emery paper and you may have affected an easy fix.