Customer Reviews
Rock Tumblers

 Home » Rotary Tumblers » Thumler's » Oiling Instructions

Oiling A Thumler's Tumbler Motor and Bearings

Oil ports on Thumler's tumbler motor
This image shows the location of the two oil ports on a Thumler's tumbler motor. Place one drop of SAE 20 oil in each port once a month.

Oil Your Rock Tumbler Monthly

Thumler's Tumblers should be oiled after each month of operation. The motor should be oiled and the bearings should be cleaned and oiled.

These are very easy jobs. Oiling the tumbler will prolong its useful life and help it run more quietly. These oiling tips apply to the following Thumler's Tumblers: MP-1, A-R1, A-R2, A-R6, A-R12 and Model-B.

Thumler's tumbler bearings
It is recommended that all four bearings get cleaned and oiled once a month. This photo shows the location of the bearings on a Thumler's tumbler base.

Oiling the Motor

The motor on a Thumler's Model A-R tumbler has two oil ports. After each month of operation you should place ONE drop of oil in each of those ports. The photo at right shows the location of these ports. Thumler's recommends using SAE 20 oil for lubricating the motor.

We purchased a small can of 3-IN-ONE oil that is SAE 20 weight with a convenient applicator spout. You can see it in the photo below. It works great for oiling the motor.

There are many brands of SAE 20 oil. We chose 3-IN-ONE because of the convenient applicator tip. A can like this one will last for many years because you only use two drops per month.
Oiling Thumler's tumbler bearings
To oil the bearings place a drop of oil onto the shaft next to the bearing and manually turn and slide the shaft back an forth to ensure that oil gets between the bearing and the shaft. Wipe off any excess oil.

Oiling the Bearings

Is your Thumler's tumbler squeaking? If it is, most likely your bearings need oiled. There are four plastic bearings that should be cleaned and oiled after each month of operation. The bearings will last longer and operate quietly if they are lubricated and kept clean. The bearings are located at both ends of each shaft.

Before oiling, use a paper towel or a rag to wipe any excess oil and/or dirt from the part of the drive shaft that contacts the bearings. Grab the shaft near each bearing with a rag and rotate the shaft with your free hand to remove any excess dirty oil and debris.

After it is cleaned apply one drop of oil to the drive shaft immediately adjacent to the bearing. Then, rotate the drive shaft and slide it back and fourth. Capillary action will cause the oil to flow between the drive shaft and the bearing. One drop per month on each bearing is all that is needed. Do not get oil on the drive belt, rubber or nylon rollers.
SAE 20 3-in-1 oil

Wash Off Excess Oil

Keeping the tumbler clean of excess oil is very important. Oil attracts and holds dirt and moisture. Dirt on the bearings will cause excess wear. Moisture can cause metal parts to rust.

Oil can also damage the soft parts of your tumbler such as the barrels, belt, and rollers. If you accidentally get oil on any of these soft parts, clean it with a rag or paper towel that has been moistened with a gentle soap - such as Dawn dishwashing detergent.

Happy Tumbling

Following the lubrication and cleanliness tips above is easy and will help your tumbler run quietly and efficiently for a long time. Many of our customers have tumblers that have been in operation for decades of regular use.

Article Authored by

Brad Cole Bradley Cole: Bradley is the manager of and has authored much of the content on this website. He also does customer support, photography, maintains the website, and consults with customers about rock tumbler repair and maintenance.
Hobart King Hobart M. King: Hobart is the owner of and has authored much of the content on this website. He has a PhD in geology and is a GIA graduate gemologist. He also writes most of the content for