Speedometer Jumping
11-07-2019, 02:08 PM
#1
Track Day
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Location: Arkansas
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Speedometer Jumping
Hey all. Curious is anyone had experienced this before.
Vehicle : 1987 944 5 speed manual 2.5. 8v
My speedometer works intermittently. Sometimes when I start up, it will work fine. Then there will sometimes be a grinding noise coming from the transaxle when I will shift to 1st or second after coming to a stop. After this happens, it will start to jump around all over the place. Gets worse with higher speed.
Anyone know what this could be related to? Where should I start looking?
My guess is there is some type of sensor back there and a gear in that sensor is broken or something like that. Haven't had time to look at it yet. All advice is appreciated.
Vehicle : 1987 944 5 speed manual 2.5. 8v
My speedometer works intermittently. Sometimes when I start up, it will work fine. Then there will sometimes be a grinding noise coming from the transaxle when I will shift to 1st or second after coming to a stop. After this happens, it will start to jump around all over the place. Gets worse with higher speed.
Anyone know what this could be related to? Where should I start looking?
My guess is there is some type of sensor back there and a gear in that sensor is broken or something like that. Haven't had time to look at it yet. All advice is appreciated.
11-07-2019, 04:23 PM
#2
definitely the sending unit, but you should check the grinding and hope it is not the ring gear and pinion going bad. We sell a lot of the sending units I would start there as it is a relatively cheap fix.
11-07-2019, 04:35 PM
#3
Track Day
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Is the sending unit the thing that sticks out on top of the trans on the drivers side?
11-07-2019, 06:08 PM
#4
DR914, I am going to jump into this, as I have an issue with my tach. I have a '90 cabrio, and my tach seems to "swing wildly." So when I am at idle and suddenly rev the motor to,say, 3000 rpm and hold (and this is a typical example) the tach will swing up to 3800, swing back to the low 2000's and then after 2-3 decreasing oscillations settle at 3000. Any thoughts?