What is the difference between the 64-67 and 68-72 GM tailgate window motors? The pictures of the 68-72 motor I've found look the same as the 67 motor I have, but the part numbers are different. The older part number is all but unobtainable. 64 to 67 - 5045611 68 to 72 - 5045610
I looked at some of my power window motors, from 64-67 GM A body wagons. They all have 5045391 stamped into the aluminum gear housing of the electric motor assembly. Can't see any other part numbers. You can just about make out the part number in the picture on the one to the lower left. There is a difference on these motors even tho they have the same p/n's. Some have 3 bosses on them, I suspect that the ones with bosses on them were replacement motors. I used one of these in my car. I had to use a cut-off wheel and cut the boss that is farthest from the motor itself off. You can see in the picture, tho it maybe hard to make out, the one in the upper right had this boss trimmed down crudely. It interferes with the stamping in the tailgate that the regulator assembly bolts on to. hope this helps.
The motor hasn't failed yet, but struggles to open or close the window. There is a 64-72 Olds master parts catalog online here: http://www.oldsmobility.com/mpc/index.htm The specific page with the tailgate motor is http://www.oldsmobility.com/mpc/group12000/text07.htm 5045611 is also listed for 68 to 70 wagons with the single action tailgates.
I would take the regulator/motor assembly out and clean then regrease it. You can take the pinion gear out of the electric motor and regrease the worm gear on the motor. Be careful when removing the motor from the regulator assembly. The spring loaded arms can take off on you. Have someone hold the arms when removing the motor and slow let the arms go where they want. Before you do this look at the gears on the arms. there are stamping/index marks on the gears and the strap that covers the gears where they mesh. You may have to run the motor to get them to align close enough to see how they align with each other. This will let you reassembly while its aligned properly.
