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As above, it was stuck down, but ive got it back up....
what is happening is the horizontal channel is hitting a hex head bolt that looks like its holding a bracket on the motor, when its on the way down, it can force its way over it, then hasnt got enough power to get back over it on the way up.
If i lever it with a screw driver, it goes up, no problem..
Something must have moved for this interference to be occurring..
Any clues?
This has been happening for a while, as I did notice the window would "jump" on the way down and up, but its obviously got worse to the point it cant force its way over it on the way back up.
No telling how long its been like this, but the "jumping" was noticeable when I bought the car 7-8 years ago.
How much play/movement is in the door glass. Could the door glass have enough movement in it, to cause it to be out of place, and hitting the bolt.
There are 4 nylon rollers on each door glass, one in the track, one on the glass and two attached to the regulator. Over time, they wear out and will get very sloppy. Once the glass is out, the ones on the glass and in the track, are easy to replace. The two on the regulator are a little more work to do, as they're riveted to the regulator.
What kind of shape are the anti-rattle cushions in? There are two of them at the top of each door. Check to see if they're worn out, or out of position.
Finally, are you sure that the track is actually hitting the bolt? A common problem with 68-82 power window regulators, is the regulator gear. The gear on the motor, is stronger than the one on the regulator, often chipping teeth off of the regulator gear. When you have a couple missing gear teeth, the door glass will "jump" like you described. Normally you'll start with a little bit of jumping, as you skip over the missing teeth. Eventually you'll lose enough teeth that the glass won't move, because the gap caused by the missing teeth, is to wide for the motor gear to reach the next tooth.
I wouldn't be surprised to hear that once you get into the door, that you find the regulator gear, is missing a number of teeth.
How much play/movement is in the door glass. Could the door glass have enough movement in it, to cause it to be out of place, and hitting the bolt.
There are 4 nylon rollers on each door glass, one in the track, one on the glass and two attached to the regulator. Over time, they wear out and will get very sloppy. Once the glass is out, the ones on the glass and in the track, are easy to replace. The two on the regulator are a little more work to do, as they're riveted to the regulator.
What kind of shape are the anti-rattle cushions in? There are two of them at the top of each door. Check to see if they're worn out, or out of position.
Finally, are you sure that the track is actually hitting the bolt? A common problem with 68-82 power window regulators, is the regulator gear. The gear on the motor, is stronger than the one on the regulator, often chipping teeth off of the regulator gear. When you have a couple missing gear teeth, the door glass will "jump" like you described. Normally you'll start with a little bit of jumping, as you skip over the missing teeth. Eventually you'll lose enough teeth that the glass won't move, because the gap caused by the missing teeth, is to wide for the motor gear to reach the next tooth.
I wouldn't be surprised to hear that once you get into the door, that you find the regulator gear, is missing a number of teeth.
Thanks for the reply...
I should have said, I've removed the door card and can see the track hitting the bolt.
It hits the bolt head when it's about 85% of the way down, and I can lever it over the head of the bolt on the way back up with a blade of a screwdriver.
Everything looks tight and as it should be, it's not the actual horizontal track that's hitting, it's the diagonal "X", that connects to the horizontal track. The forward diagonal that terminates at a roller that sits in the horizontal track is the culprit
(If that makes sense?)
I'll see if I can get a pic...it's all very tight in there!
Sat back and thought about this problem...then took a look at the door itself....hey presto!
There is only one rivet holding the motor in place!
A closer inspection found the remains of a second rivet in the door.
So the motor looks like there is only two rivets holding it to the door - with one gone, it has "rotated" on the remaining rivet a distance of the hole itself.
I'm hoping that when I return it back to its normal position, it will operate properly (fingers crossed)
There's a LOT of torque in these motors, and probably a combination of age and dried out lube on the runners, probably conspired to shear the rivet!
also in your pics, the arm that is pointing up towards the camera looks like it has a bend in it about 4 inches up from the end causing the piece that hits the bolt to be pushed closer to that bolt.
1978 corvette power window was stuck
