Have a 2001 buick lasabre ;it jerks when it changes gears either speeding up or slowing down. What Causes this? I just got it out of shop and they replaced both shift lock solenoids. It still is jerking. Seems to have helped when they changed the shift lock solenoids as it does not jerk as much. Can you help
What’s happening is what is called ‘harsh’ shifting.
Sometimes a tranny fluid and filter change will cure this. (It worked for me, luckily)
What usually causes this in these GM trannies (So I’ve been told) is a worn pressure control solenoid (inside the trans)
shift lock solenoids?
PLEASE MORE INFO ON THOSE SOLENOIDS.
You don’t mention what engine size or transmission (3 speed or 4 speed overdrive) so I will supply a generic answer. A lot of GM transmissions are now computer driven. The computer decides when to shift and how quickly to apply the friction clutches. If the computer finds a problem with the operation of the transmission, it will try to correct it be best it can. If it decides that it is unable to adapt the shifting, it will go to full pressure shifts and/or ‘limp home’ mode which usually is second and reverse only and the ‘OD’ light always on or flashing or the Check Engine light will be lit. Also, please supply any information regarding the service done on the transmission and the mileage on the transmission.
The shop you took the car to should have scanned the computer for trouble codes. They might have done this because they zeroed in on the ‘shift lock solenoids’ which hopefully were the pressure modulation solenoid(s). If that shop has the capability of diagnosing the problem, take the car back and tell them that the problem is still present. Have them diagnose a little more.
Hope that helps.