Today I went out to replace both the power window motors on my car. I bought the two for one special off ebay. Two brand new motors for $44.95 with free shipping. Before doing any dirty work, I decided to see if the original motors could be saved. I stuck a WD-40 straw up through the service ports on the bottom of both motors and injected them with lithium grease. I also greased the gears and regulators. The drivers side motor cleaned up real nice. This motor was originally a tad slow and had a hint of grinding present past half way down. The lithium grease DRASTICALLY improved the performance of this motor, to the point where I didn't deem it necessary to replace. The motor actually is quite speedy speedy now. You'd think it was a new car if you were just going off the window alone. No more grinding either a nice smooth electrical motor sound all the way up and down. The passengers side window however, was so shot it actually made It's condition worse. The pass side had a bad grind to begin with but now it just sounded horrendous. It was also moving much slower than before to the point where you thought it was gonna bind up any minute. I played a set of taps then got out the drill and got to work. I took the easy way around. First drilling out the two main rivets, then making 3 small holes in the door so I could get to the rivets holding the motor to the regulator so I wouldn't have to remove the whole regulator/motor assembly out the back of the door. I bolted the new motor up, greased it and then tried it out. It was much better than the old motor, but the results we're pretty disappointing compared to what I thought I was getting. Motor runs smooth, with zero grind. But it is slower than what I expected. Slower than the rejuvenated 25 year old original motor. It seem the start off fine, but as the window gets near the bottom of the door, about halfway down, the motor slows down and the window begins to creep. Nowhere near as bad as the old motor but slower than what you'd expect for a new motor. I pulled this motor out and bolted up the second new one I had Same result . I tried running the motor not bolted to the door and it spun consistently, so I know It's not the motor binding. If I race both the windows against each other, the drivers side beats the pass side window by about 1.5 seconds every time. I check the window stops and they are not putting excessive pressure against the glass. Also, the pass side window gives a thud whenever it goes all the way inside the door and stops, or if you go to roll it up right as you hit the switch it makes another thud sound as it starts to move back up. What to do now?

That sounds like the rubber stopper on the bottom is missing allowing the window to go down to far. If that happens the top edge of the window will go past the bottom of the outer sweep, and can get stuck on the screws. If you notice two chips on the outside top edge of the window, that what it is. This is very common on thirdgens with power windows.

Jay, I'm pretty sure this is the problem. I haven't noticed any chips on the glass but I did find a couple moderate suzed round rubber pieces in the bottom of the door that were falling apart. I also found chunks of weird looking red stuff. I want to say It's bondo, but #1 unless someone was making bondo swiss cheese I have no idea what It's purpose was and #2 I see nothing on the door that has been or needs to be bondo'd, with the exception of the drivers door that is rotting along the underside edge. But there is no evidence that this has been bondo'd in the past.

As for the window motor going slow, does anyone here have any ideas why the regulator could possibly be binding?

The rollers are sticking, for one, and the channels need to be removed, cleaned and lubed, for two. You should have done it right and cleaned the crap out of all of the window channels while you were in there as well as made sure that the rollers actually roll in the channels without sticking and sliding.

BTW, that red stuff is body sealant. It's all over the place inside the doors.

I got my IROC back in January of this year and notice two chips on the top of the windows. I always wondered how it happened. Now I know My power windows are slow as well. Looks like I need to dig in as well and clean it up.

Would somebody be able to show or describe to me in detail where these rubber stoppers go so I will know how to fabricate some replacements?

Tomorrow I will take out the channels and clean them and post back with results.