1965 Bonneville power window regulator Counter balance spring


New member
After dealing with windows that need human help to go up since owning my 4 door 1965 Bonneville since 1970 I decided to replace all 4 motors.
I started with the front passenger door and everything works good. The motor came from an ebay seller selling new motors.

After replacing the front drivers door motor with a motor that came from Lectric Limited the window goes up albiet laborously but going down it flys down with a vengence and slams onto the lower rubber limit bumper.

When taking the old motor out of the regulator the regulator rotates away from the gear teeth for about 180 degrees. Then, the counter balance spring is completely un-tensioned. I removed the spring , cleaned up the entire regulator , greased up rotating parts.
To install the new motor the regulator motor bracket has to be rotated about 180 degrees to get the motor to the area where the teeth are. This creates the downward load which aids the motor in running the window up.
I know what you are thinking, Rotate the regulagtor an additional 360 degrees.
it takes a lot of force just to get the motor bracket to rotate 180 degrees.
That will place a tremendous abount of torque on the spring. In removing the motor for both doors, which was never done before, the motor bracket rotated only 180 degrees after removing the factory installed motor.

So, is the problem a spring that has lost its strength?
I would appreciate any ideas or solutions anybody may have.


Staff member
Im trying to offer a way to test without actually seeing what you are dealing with.
Are the springs unique to each door?