Liftmaster 81C168 Garage Door Screw Drive Carriage Rack

by Chamberlain

Product Description

81C168 Screw Drive Carriage Rack

Product Details

• Shipping Weight: 5 ounces (View shipping rates and policies)
• ASIN: B000NBGNW0
• Item model number: 81C168
• Average Customer Review: 5.0 out of 5 stars  See all reviews (3 customer reviews)
• Amazon Best Sellers Rank: #15,215 in Home Improvement (See Top 100 in Home Improvement)
  • #71 in Home Improvement > Hardware > Garage Door Hardware > Garage Door Openers

Customer Reviews

Most Helpful Customer Reviews

6 of 6 people found the following review helpful:

5.0 out of 5 stars A Simple Fix for an Annoying Problem, February 27, 2011

By 

David Bower (Houston, Texas, USA) - See all my reviews
(VINE VOICE)    (TOP 1000 REVIEWER)   

Amazon Verified Purchase

This review is from: Liftmaster 81C168 Garage Door Screw Drive Carriage Rack (Misc.)

Update March 1, 2011
While researching the part I found conflicting information on the web concerning lubrication of the screw drive assembly; some sources indicated the screw itself should be lubricated to facilitate the operation of the rack and others omitted such references. I decided to call Chamberlain and was told the rail, not the screw, could be very lightly lubricated every 12 inches to facilitate operation of the trolley. They specifically said the rail and not the screw and emphasized the minimal use of lubricant.

Original review
We have always appreciated the convenience offered by a garage door opener so when it made a really loud racket and stopped working we were definitely concerned.

Being something of a do-it-yourselfer I started researching the LiftMaster screw operated garage door opener and soon discovered the weak spot in the design; the infamous screw drive carriage rack. It took a little research to find the exact name of the part but the web came to my aid again.

After I discovered its real name which is screw drive carriage rack and checked Amazon sure enough they had that part. I placed an order with Amazon but the part must have gotten lost somewhere because it never came in. Amazon refunded my money and suggested one of the other suppliers so I chose U.S. Door Control who did a stellar job of getting the part to me well ahead of schedule.

It was then up to me to install the rack; being one of those who always read the instructions I wanted to see if I could find anything on the web that would give me a step-by-step guide to how best to do this. Fortunately the Chamberlain Group has a website where after a little searching I found just what I needed; "Screw Drive Rack Replacement" which is a complete guide to the replacement process.

These instructions are not easy to find; put Chamberlain Support Center into your search engine. You should get something like [..] with a space to type in "screw drive rack replacement instructions." That should take you to a new window with Screw Drive Rack Replacement Instructions listed on top - you should see "To download a copy of the Instructions click the Download Instructions button below. Download Instructions Date Updated: 08/16/2010" This will take you to the same instructions I used to install mine.

I assure you I would not have guessed the steps listed if left to my own devices. While waiting for the part, which wound up taking a lot longer that I thought it would, I spent my time studying the instructions and mentally going through the replacement process.

Finally, with part in hand, I was ready to replace the worn rack and sure enough after I got it out the old rack was almost worn smooth. Following the instructions I was doing great until I got to the actual replacing of the rack on the rail; I discovered the garage door spring assembly got in the way of the rail when I tried to drop it down. After some experimentation I discover the entire LiftMaster unit would flex enough to get the rail down below the spring.

Continuing to follow the instructions I replaced the rack, reattached the rail and ran the test. For some reason the upward and downward travel had to be adjusted but that was relatively simple following the instructions in the Owner's Manual and on the replacement sheet I had downloaded.

I have left out a lot of detail available in the replacement download I mentioned. Suffice it to say I really needed those instructions! The job is not difficult if you're prepared; the replacement instructions are, however, vital if you're not a garage door repairman!

1 of 1 people found the following review helpful:

5.0 out of 5 stars Saved me money on a new opener, March 21, 2010

By 

M. Floriani "Floors" (Rhode Island) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Liftmaster 81C168 Garage Door Screw Drive Carriage Rack (Misc.)

I an a master electrician from Rhode Island.This part enabled me to fix the opener without buying a whole new unit.Still wish I had bought a chain drive unit for the door, however that is not the replacement parts fault.

5.0 out of 5 stars Garage door is working!, February 25, 2011

By 

T. Kim - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Liftmaster 81C168 Garage Door Screw Drive Carriage Rack (Misc.)

My garage door slipped one day almost crushing my car. I took the carriage rack off the rail and found that it had been worn to the point where it was not gripping the screw drive. I got a replacement and now my garage door is operational without fear that the door will come down on my car and/or my kids.