Screw Drive Rack K081C0168 81C168 Replaces Chamberlain LiftMaster Sears Craftsman

Works as advertised! Must be comfortable with doing removal and replacement… one of three screws to attach unit is a bugger… very tight space even with small socket wrench. Happy so far.

Craftsman Opener was 15 years old- this part brought it back to new life. Easy install- watch the YouTube videos.

No instructions included, BUT plenty of videos on YouTube and other sites. I only used the new main gear as all of the old existing parts were still very good in the 20+ year old Sears unit. Total time from removal to installation was maybe about 2 hours, to be sure that it went together the right way. Works flawlessly now, and so much quieter. An easy do-it-yourself project if you have the right tools.

Had the door springs tightened and they saw the shaft had worn out on the bearing in the motor. Saved myself $160 by doing it myself. Watch a copy vids on YouTube to make sure you get the correct items and then tear it down and replace it. Took about an hour to do on my Liftmaster opener. Everything fit perfect and had zero issues with the clips not the gears. Lots of grease included which was good. Be sure to check both gears since they both may need to replaced. Mine just needed the main sprocket and shaft. You don't have to remove the motor or take it down to do the replacement.

Replacing gear on an old 1991 model. Most parts fit perfectly, but some (shaft bearing, W-clip and worm gear on motor shaft) weren't exact. Worm gear on motor shaft was a tight fit. Save your old parts just in case - had to use the old shaft bearing. W-clip fit after some gentle filing. This kit was inexpensive and only replacement I could find.

So the drive gear on my garage door opener became worn and the chain kept coming off. My first thought was to buy a new opener for about $200. Then I stumbled on the gear assembly for about $10 (I think it's about $15 now). It was relatively easy to replace the old one. Since the assembly doesn't come with any instructions, I highly recommend checking out a couple of YouTube videos which will make getting the chain repositioned correctly after the gear assembly is installed.

Multiple issues with this kit.- The clip that holds the position sensor gear must be removed (and replaced) for installation. However, when I tried to remove the clip, it wouldn't budge. I finally ended up breaking the clip and using a drift pin to drive the remnants out of the hole in the drive shaft. The problem was that the hole in the shaft was too small (~ 0.020" as compared to the OEM part) and also had a burr on one end. I drilled out the hole to proper size, and used the clip from my existing opener.- The worm gear would not fit over the motor shaft. The inside diameter was 0.010 to 0.015" too small. The part is molded of a relatively soft plastic (nylon ?), and so I was not able to drill out to the right size (ever try to machine jello ??). The OEM worm gear is of a fairly hard plastic. Also, the quality of the part was abysmal. There was excessive flash from the mold separation line, and even a void on the ID where the mold did not completely fill. Fortunately, the worm gear on my existing opener was in good shape, so I could use that.- The main drive spur gear appeared to of "ok" quality, But when I tried to assemble the unit, the gear did not mesh well with the worm gear. It appears that the pitch diameter is larger than the OEM part (I have no way of measuring that). I was able to jam it together, but the gears are under a lot of pressure. Because of this, I expect the gears to fail soon, and perhaps also the bearings on both the motor and main drive shaft.On the positive side, the metal parts (sprocket, bearings, etc) all seemed to be good quality.

The manufacturer forgot to tap the threads in the screw holes that mount the sheetmetal piece to the garage door frame. If I didn't own the correct (10-32) tap, I would have had to ask for a refund. Otherwise everything fit. This kit was very comprehensive, including replacement washers, brass bushings, and roll pins.