I repaired my Front and Rear Passenger-side Windows on Saturday. First of all, big thanks to B-body Builder and everyone who has contributed to this post over the years for all the excellent advice! I've read through it several times over the past 8 months or so to prepare, knowing I'd need to set aside a day for it. Also - I like to work on bigger projects like this when I'm with my Dad - since he was an Engineer for GM and used to have me work on car repairs with him when I was young.
I'm not going to go into all the details, since they would be redundant, but I will mention a few things. Hopefully they will help convey my experience... This will only make sense if you've read the thread a few times and maybe you'll want to re-read my description as you are actually working on the project to really understand what I mean.
Doorman #74444, Window Regulator Rollers, $3.51 ea on RockAuto
Doorman #45115 (700-343) Door Panel Retainer / Clip, Box of 25 for $7.75 on RockAuto
Lucas Oil White Lithium Grease 8oz
Hillman 10-24x1/2 Combo Round Machine Screw
My Lowe's did not have the 10-24 Lock Nuts in stock, but had another brand equivalent
(by the specialty drawers, far away from where I found the round machine screws)
Follow all of the instructions as written. If you've not done this before, I do recommend you remove the door handle brace from the back door, as it gives you a lot more room to operate. I didn't at first and was really struggling until I said "screw it" and removed that. Also, if you are doing both front and back, start with the back door, as that's easier to figure out than the front and once you've done this once the next repair is easier.
Once I drilled out the rivets that holds the window brace to the rising track, I very easily pulled the window up and taped it out of the way. Then, I was able to reach into through the access holes to twist the sliding bar 90-degrees so that the unbroken clip just popped off the ball joint of the lifting bars. I got the rising track out of the door through the access holes, and then I bent the crimps out and slid out the broken pieces of plastic sliding clips. I greased up the track, slid in my two Round Rollers, and then re-crimped the end of the track.
I put the bar back into the door and lined up the first roller, it easily popped into the ball joint on the lift arm with a squeeze of my big self-locking "Alligator Pliers" which were adjusted for the proper width of the track over the connector. I used the power switch to move the lift, got the other side to a place I could access, and used the Alligator Pliers again to pop in the other ball joint. I then used my ratchet to disconnect the stationary track for the single slider from the door, twist to pop it off the ball joint, remove, regrease, replace with a round roller, pop onto the joint with my Alligator Pliers, and then reattach the bolts. This was all on the back door.
I reattached the rear door handle brace with 5/16" hex-head bolts, 1" long (but 1/2" probably would have worked), with a flat washer, locking washer, and nut on the back of each. They were rock solid when tightened and the bolts were not in the way of anything internal. The front door handle brace does not need to be removed. I used a shop vac to suck out all the debris that fell into the door interior once I was done working in there. Also - while I didn't mention the plastic barrier before, this is obviously something I had to cut up a bit to move out of the way. I used a lot of duct tape putting it back together... hopefully it will be an okay long-term solution.
On the front door, I followed pretty much the same process. I do want to mention that you will need to remove the speaker to open up an access hole, but it is easy to do. I got a reminder that you definitely want to replace all three of the plastic sliding clips with rollers! When I inspected these tracks, I found that the stationary track already had a round roller. In other words, a previous repair had obviously been done, but since that time one of the two sliders in the rising track had become brittle and broken, so here we are again. The good news is, since this was already a round roller and it felt like it was in good shape, I didn't see the need to replace it like I would replace a clip.
The big difference on the front door is that since the access holes are in different places, it was simply not possible to use the Alligator Pliers to pop the round roller onto the ball joint - you don't have the space to maneuver. Luckily, I did have a 2-inch C-Clamp and was able to have the driving rod stick out of a small access hole to tighten it for the same result. It was still a lot more difficult to raise the bar into the right place and get everything lined up - but possible with some patience... and it helps if you have some experience, which is why I recommend doing a rear window first if you're doing both rear and front. In fact, I'm willing to bet from my own experience there are a lot of Caprices and Impalas out there with rear window problems that aren't fixed because they are easy enough to live with until the front goes bad too ;-)
Anyways, that should be a pretty good summary of the lessons I learned. It took me about 7 hours of total work, because I was going slow and talking with my dad a lot. That does not include the breaks we took for lunch and dinner. I have 4 round rollers and 20 door clips left, so I may check on my driver's side doors at some point in the future so see how they are doing.