TaiChiGuy

Power window on 71 does not want to up. Even with assist pushing from bottom or pulling top edge, motor struggles getting window up. Down is not a problem (motor sounds normal going down).

How to diagnose problem is motor, window regulator, or mechanical binding-adjustment, etc.? Any repair/adjustment advice? BTW, window adjustment procedure?

toobroketoretire

Most likely a broken spring. Without the aid of the helper spring a window will power up very slowly and power down real fast. All of the Corvette vendors stock them.

F22

It might be the spring, but most likely, it is the motor, trying to overcome the 44 year old grease, that has by now, hardened into clay. If you've haven't done it yet, go in there and clean up out all the hardened grease and lube it with fresh grease. Far easier than replacing the motor. Don't go crazy with the lube. Put it only where it needs to be.

0Willcox Corvette

I think if I were you I'd tear into the door and see if you can ID what is wrong. Gear, Spring, Motor binding.. A good cleaning and re-lube and possibly a spring might go a long way.

But the only way your really going to know is to remove the regulator and see.

Willcox

DUB

YES...lots of advice.

AS for you asking about a window adjustment procedure....well...that depends on the parts that are worn in your window assembly currently.

The front and rear rollers for your vertical tracks...if they have 'in and out' play in them....then attempting to adjust a window and have it do what you want is POINTLESS. A 1/32" or grate in and out play equates to a lot of in and out play a the top edge of your door glass when it is raised....due to the distance from the top edge of the door glass down to these roller is roughly 12 inches + or so. And if the argument that the window has two felt stops that press against the door glass....well that is just changing the fulcrum point of the glass. And then a person will wonder why the glass does fine when the door is closed and you can roll it up and down....but if the door is open and the window is up and you try to close it...it may not close correctly and hit the blow-out clip or actually hit the body at the 'B' pillar.

DUB

7T1vette

You might want to first check out the window switches. If the switch contacts are carboned-up, they won't pass enough current to properly run the motor. You can just turn the switch socket around so that the switch action is reversed (UP is down; DOWN is up). If the problem stays with a particular side of the switch, disassemble the switch and clean it out; then reassemble and reinstall. If the problem stays with the window [direction], the problem is with the spring or motor.

Although, if it's the motor, I'm not sure why it would work well in one direction and not in the other. (same motor~)

0Willcox Corvette

If you do test the switches, here is a paper I did for testing the entire system a while back.

TaiChiGuy

Didn't see a spring in assembly manual-where is the spring located? Thanks.

0Willcox Corvette

The spring is already on the regulator so it won't show up in the AIM.

7T1vette

Just so you know:

There is a specific procedure for removing the motor and/or window/regulator from a power window car. You need to get a copy of that, either from the Chevrolet Chassis Service Manual for your year car or cabbaged from the internet. If you don't follow the right procedure, you can screw up the window mecanism, break the glass, and/or do damage to your arm.

Snoopysvet

I had a problem with my widow as well
The grease became hard, all I did is was scrape all the grease out, blasted the residue out with brake cleaner put in some lithium white grease and put it all back together!