my irobot roomba 694 keeps getting stuck and making a weird grinding noise, what's going on?

Diagnosis

The grinding noise in an iRobot Roomba 694 is almost always caused by "bearing seize." Over time, long hair, carpet fibers, and fine grit migrate past the rubber seals of the main brush roll and wrap tightly around the end caps (bearings). As this debris compacts, it creates immense friction, preventing the brush from spinning freely. The grinding sound you hear is the motor straining against this resistance or the plastic gears inside the drive module slipping under the load.

This mechanical resistance triggers the Roomba's internal sensors, which detect that the motor is drawing too much current to rotate the brush. To prevent the motor from burning out, the robot will stop moving and report a "stuck" error. You can confirm this by flipping the unit over and attempting to spin the main brush roll by hand; if it doesn't spin with a smooth, loose motion, the bearings are clogged. Additionally, check the front caster wheel; if it doesn't pivot 360 degrees freely, it can cause the robot to "plow" into walls, creating a similar mechanical strain.

How to Fix It

Follow these precise steps to clear the jam and restore the drive system:

1. Power down the unit completely by pressing and holding the CLEAN button until the lights fade, then ensure it is removed from the Home Base.
2. Flip the Roomba 694 upside down on a flat, clean surface.
3. Locate the two plastic release tabs on the main brush module frame. Press these tabs inward and lift the brush guard to expose the two main rollers.
4. Grasp the brush rollers and pull them straight out of the module.
5. Slide the plastic end caps (the bearings) off the ends of the brushes. You will likely find a dense "donut" of hair and lint packed tightly against the axle. Use a pair of precision tweezers or a seam ripper to cut through this debris. Do not pull the hair out forcefully, as this can warp the plastic axle.
6. Clean the interior of the brush module housing. Use a can of compressed air to blow out any grit or pebbles trapped in the gear housing.
7. Inspect the side-brush (the three-pronged yellow brush). Pull it off its screw and remove any hair wrapped around the base of the stem.
8. Reinstall the cleaned end caps, slide the brushes back into the module, and snap the guard back into place.
9. Test the front caster wheel. Pull the wheel assembly out of its socket and remove any hair trapped in the axle. Wipe the axle with a damp cloth and snap it back in.

If That Didn't Work

• Replace the Brush Roll Assembly: If the grinding persists, the internal plastic gears of the brush module may have stripped teeth. Replace the brushes with a new set (Part # 694-BRUSH-KIT). If the noise continues with new brushes, the motor itself is failing.
• Deep Clean the Drive Wheels: Check the two large main drive wheels. Gently pull the wheel out of the chassis. Hair often wraps around the wheel axle, causing the robot to veer or "stutter," which can sound like grinding when the robot tries to correct its path.
• Inspect the Vacuum Motor: If the grinding is high-pitched and occurs even when the brushes are removed, the vacuum impeller may have sucked up a small pebble or piece of plastic. Use a flashlight to look into the vacuum exhaust port and remove any visible obstructions with a needle-nose plier.
• Perform a Soft Reset: Hold the CLEAN button for 20 seconds until the light ring flashes. This clears the temporary error cache and forces the robot to recalibrate its motor torque settings.

Heads Up

• Bearing Maintenance: To prevent future grinding, remove the brush end caps every two weeks and clear the hair. Waiting until the robot reports an error often means the motor has already been stressed.
• Avoid Wet Debris: Never run the 694 on damp floors. Moisture causes dust to turn into a "paste" inside the bearings, which hardens and acts like glue, leading to permanent motor failure.
• Check Brush Compatibility: Only use brushes specifically rated for the 600 series. Generic "universal" brushes often have slightly different diameters, which can put undue pressure on the gear assembly and cause premature wear.
• Caster Wheel Care: If you have hard floors, the front caster wheel can collect "dust bunnies" that restrict movement. A quick wipe with isopropyl alcohol on the axle every month keeps the robot tracking straight.