Speed unit failure

fultwst · 02-23-2005, 02:41 PM

My speedo on my R1100S is toast. I have a 2001 abs model. The needle jumpes around from 0 to 20 mph when im moving at most any speed. I traced the wires looking for tears, brakes, pinches but nothing. I took the bike to an indipendant mechanic and he was no help.So I shelled out the $50 for a new sending unit (a little magnet on a 20" piece of wire) and my problem is still there. Now I need a BMW mechanic close to Sherman Oaks CA. Can anyone give me a referral? Thanks for reading......... ~Paul

jclark · jclark's Garage

The most common problem is a wire breakage between the sender ( in the rear drive housing ) and the connection to the main harness. Sometimes the connector itself.
Look again. It's OK to test, but verify. ( ya- it's a Reagan quote, and I don't even like him )

jeff
..I'll quote anybody for a yukyukyuk..... ( I'm tryin' t'think, but nuthin' happens... )

Rapid Dog · 02-24-2005, 12:06 PM

hmmm....you know Twist, there is always West Valley...which is closest...but be prepared to be insulted, perplexed, and denied

but that IS the closest to S.O. man...

flaudeman · 02-24-2005, 08:30 PM

I had an issue with my speedometer bouncing around as described.
There is a sending wheel inside the rear drive unit which spins with the crown gear and the sensor reads the pulse as it spins. It had broken free and was freewheeling on the hub. The dealer tried a quick fix of Loctite and staking it to the hub but the fix didn't last six months. Ultimately, the rear drive unit was replaced. The mechanic discovered it by removing the sensor, poking a thin screwdriver into the hole, and gently trying to spin the sending wheel.
Good Luck,
Fred