When Liftmaster chain drives openers make loud noises it is because of several different reasons. It will either be a problem with the motor itself, which almost never happens. In 15 years in the garage door business I have only replaced one motor that was covered under factory warranty. The most common malfunction is the gear and sprocket drive system. It can be as simple as properly lubricating the chain itself. The other possible issues will be the sprocket that turns the chain can be about to give out. The tell tail sign that the sprocket is breaking off is a sagging chain.

chain has been adjusted too tight

This Happens when a chain has been adjusted too tight at the time of original install and the chain puts too much pressure on the sprocket and in about 5-10 years the sprocket eventually shears off the post that turns the sprocket. Also there is a plastic wheel opposite end or the drive sprocket located at the front of the opener rail right where the rail screws into the wall above your garage door. This plastic wheel acts like a sprocket but does not have any teeth its just there to guide the chain.

The wheel will sometimes break apart and cause noise

Sometimes there is a chain guide that screw into the top of the motor head right in front of the chain sprocket. Liftmaster designed this chain guide to spread the chain out a little bit to keep the chain banging against the metal rail as the chain moves along. The plastic chain guides can deteriorate and pieces will break off causing the chain to make noise as it travels thru it. There aren’t any other factors that I can think of on a chain drive opener that make it loud and noisy. So it has to be one of the issues I mentioned above.