Liftmaster making loud BANG noise

My Liftmaster is about 3 years old. For the first few years, every now and then, it would make a loud bang/crack noise when starting to close the door. Other than that, it operates fine.

But now it's doing it EVERY time it starts to close the door. Also, every few weeks, I need to reset the travel limits as they're off by an inch. I'm guessing this is related. Is something wrong with the motor? Are gears slipping?

Is this an easy fix for a somewhat-capable person? Or do I need to call a repair company?


Here's a video link with sound. In person, it sounds way louder and scarier:
https://imgur.com/a/2m3fglW

Gear & sprocket assembly could be going out. Possibly a bad mechanical limit switch. Here are two links to those parts. However, take the cover off the back of your powerhead (3 or 4 philips screws) & take a picture with light of what it looks like in there, videos are even better.

Gear & sprocket assembly:
https://www.amazon.com/Liftmaster-Chamberlain-Sears-Craftsman-41a4885-2/dp/B0722NPNJT/ref=mp_s_a_1_1_sspa?dchild=1&keywords=liftmaster+gear+and+sprocket+kit&qid=1602920366&sprefix=liftmaster+gear+and+sp&sr=8-1-spons&psc=1&smid=A36RV344P5JWP3&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUlVGNks5T1g0TDYzJmVuY3J5cHRlZElkPUEwMzI1OTUxMThCSUlKWjdHUTFRWiZlbmNyeXB0ZWRBZElkPUEwNDY0NTI4MkpWMFpZMFpLWjMyQyZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

Mechanical limit switch:
https://www.amazon.com/LIFTMASTER-Garage-Openers-41D3452-Assembly/dp/B000FPVOVY/ref=mp_s_a_1_1?dchild=1&keywords=liftmaster+limit+switch&qid=1602920387&sr=8-1

Because it’s bouncing around & making so much noise. It is probably your gear & sprocket. Super easy fix btw. (Take off bottom little gear, unscrew the 3 5/16” screws you see in your video around the gear the belt rides on, & you pull that whole assembly out of the top of your powerhead.) 3 screws & a gear clip to remove it all & replace.