speedometer erratic

1987 GMC S15
586,000 MILES • 4 CYL • 2WD • AUTOMATIC
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BK2WRK
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due to a bad speedometer cable on my '87 gmc s15, the speedometer needle was erratic at times. i've since replaced it. my question is does this bouncing needle cause the vehicle speed sensor to give the computer bad information concerning transmission shifting? i had a problem with the torque converter shifting back and to at about 30 mph for no reason.
Feb 1, 2011 at 10:28 PM
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HMAC300
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  • 48,601 POSTS
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yes it could cause it as the VSS is on the insstrument cluster. But you should have the trans checked as you may have a bad torque converter clutch switch as well. Have a trans guy check it out.
Feb 24, 2011 at 10:33 PM
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