Having problems with your 1990 Buick Skylark ?
Transmission shifts hard
\015 My car was running hot after finding that problem--radiator cap and heat sensor ---the transmission started immediately as soon as we put on new parts shifting hard -we unplugged the speedometer now it shifts fine what is wrong????\015
Your car has the 125c/3T40 model trans,3 speed automatic with lockup.When you say you unplugged the "speedometer",if you are referring to a square electrical connector on the trans,facing the radiator,that connector is not the speedometer,but the lockup circuit inside the transmission.It is likely the lockup solenoid inside the side pan has gone bad and is malfunctioning.It is a common problem on those transmissions.You will lose some gas mileage by unhooking the connector,and eventually,years down the road,will hurt the trans from the fluid running too hot.Lockup clutch application in a General Motors lockup torque convertor helps to cool the fluid.
Repair Help & Product Troubleshooting for 1990 Buick Skylark
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