C900 Slow Window Syndrome
Now it's time to fix the mechanism. If the motor is not removed yet, remove the 3 bolts that hold it on.
Now you should be able to move the mechanism up and down with relative ease. The spring will provide some resistance, but nothing too bad.
You should feel that it's harder to go down than up. This is because on the way down you are compressing the spring and the way up is uncompressing.
If you cannot move the mechanism very easily, then it's probably corroded.
I took some brake cleaner and got rid of all of the old grease that hardened up.
This cleaned up the joints and made it much easier to move.
Then you need to lubricate the joints with some silicon lubricant from a spray can, as it will not harden up.
If the mechanism still doesn't work after cleaning and new lubricant, then you will have to replace it with either a new unit or a good used one.
Luckily both are still available!
Once you get the mechanism working good, now it's time to clean up the motor.
First test the motor with some wires connected to the battery. It doesn't matter which side is 12 volts and ground as it spins in both directions.
Now listen and watch for any slugishness. Even when new, the motor is not a speed demon.
It probably moves only about 100 rpm, but it does it consistently and smoothly.
If the motor is running bad or not at all, you want to take the cover off and inspect the gearing. You may be able to save the motor and save some money!
New motors are available but they are around $100. In most cases the motors are usually worn out and cannot be restored very easily.
To remove the gear cover, use a screwdriver and pry up on each of the 4 rivets.
On the inside, you should see something like my picture and not something all rusted up with no grease.
NOTE: If you need to replace one of the parts, you can use the same side of a 4-door car.
The motors and mechanisms are the same.
If yours is rusted up, then remove the motor from the gears with the two screws and pull it out.
Now you can test the motor by itself and see if it works.
This should spin very fast and be smooth. If it doesn't spin, then the motor is dead.
If it spins fast, then you just need to clean up the gears.
Spray the gears with some brake cleaner and remove all of the old grease. This will probably take a full can to do.
Before greasing up the gears, you need to drill out the holes so you can attach the cover back on.
Use a drill tap and a small drill bit to make a hole where the 4 rivets went. Then enlarge the hole with the size screw/bolt you plan on using.
Now clean out the metal filings and grease up the gears with some light weight grease.
Make sure it isn't temperature sensitive, as it won't move at all in the cold!
I'm not sure what Saab used, but it is thicker than motor oil, but thinner than grease.
You can put some gasket sealer on the small edge of the cover to keep any water out.
Now retest the motor with some power and see if that makes any difference.
The only thing left is reassembly.
You want to push the mechanism in the full down posistion. Then wrap the motor in the wrap it came in or use something else that is waterproof.
DON'T FORGET THE WRAP! This keeps the water out of the motor!
Now attach the motor to the mechanism and test it out with some power. It should move much quicker than before!
Stuff the assembly back into the door and attach the wires before attaching the bolts!
Bolt down the mechanism, attach the window and test it out.
It should work like a champ!
Reapply the plastic liner covering the holes and reattach the panel to the door.
Now you can go do the other side!