makita lxt saw making a grinding noise and cutting really slow, blade seems tight.

Diagnosis

The grinding noise and sluggish cutting performance on the Makita XSH03Z are classic symptoms of excessive mechanical friction and motor strain. When a blade feels "tight," it usually indicates that the blade is either physically binding against the arbor or the teeth are so saturated with polymerized resin (pitch) and sawdust that they are no longer slicing the wood, but rather pushing against it. This creates a massive increase in drag, forcing the brushless motor to draw more current, which can lead to overheating and an audible grinding sound as the motor struggles to maintain its RPMs under load.

Alternatively, this specific model uses a high-torque motor that can be affected by a bent arbor or a warped blade flange. If the blade is not seated perfectly flush against the inner flange, it will wobble during rotation. This oscillation creates a rhythmic grinding noise and causes the blade to "bite" unevenly into the material, which manifests as a slow, labored cut. You can confirm this by removing the battery and spinning the blade by hand; if you see any side-to-side play or hear a metallic scraping sound against the blade guard, you have a mechanical alignment issue.

How to Fix It

1. Power Down: Immediately remove the 18V LXT battery from the rail to ensure the trigger cannot be accidentally engaged during service.
2. Blade Removal: Use the provided hex wrench to loosen the arbor bolt. Rotate the bolt counter-clockwise. Be careful not to drop the outer flange; catch it as it releases.
3. Debris Clearing: Inspect the blade teeth for a brownish, sticky residue. Use a dedicated gum and pitch remover or a mixture of warm water and mild detergent. Use a stiff nylon brush to scrub the gullets (the spaces between the teeth) until all hardened sap is removed. Dry the blade completely to prevent flash rust.
4. Flange Inspection: Remove the inner flange and inspect the arbor shaft for any sawdust buildup or metal burrs. Use a clean rag and a small amount of lubricant to wipe the shaft clean. Ensure the inner flange is seated perfectly flat against the motor housing.
5. Blade Reseating: Place the cleaned blade onto the inner flange. Ensure the teeth are pointing forward and the blade is centered. Tighten the arbor bolt firmly, but do not over-torque it to the point of stripping the threads.
6. Test Run: Reinsert the battery and run the saw in a free-air environment for 10 seconds to ensure the grinding noise has ceased and the blade spins true without wobbling.

If That Didn't Work

• Replace the Blade: If the blade is dull, cleaning it will not restore the cutting edge. Replace the current blade with a high-quality 6-1/2" carbide-tipped blade specifically rated for 18V cordless saws (which typically have lower tooth counts to reduce friction). A blade with too many teeth for the material will cause the "slow cut" feeling and overheat the motor.
• Inspect the Blade Guard: Check the retractable lower guard for any bent linkages or debris. If the guard is rubbing against the side of the blade during the cut, it will create a high-pitched grinding sound and slow the blade's rotation. Use a file to gently remove any burrs from the guard's interior if necessary.
• Check for Bearing Failure: If the grinding noise persists even with a new blade, the main spindle bearings may be worn or contaminated. Gently shake the blade side-to-side; any detectable "clunking" or play indicates the bearings are shot and the gear housing needs professional servicing.
• Verify Battery Health: A failing 18V battery cell can cause the motor to "stutter" or lose torque, which can sound like grinding under load. Swap the current battery for a fully charged 5.0Ah or 6.0Ah LXT battery to see if the power delivery improves.

Heads Up

• Avoid Gasoline: Never use gasoline or harsh solvents to clean your blades; these can degrade the bonding agent of the carbide tips and damage the paint on the tool.
• Avoid Over-Tightening: Over-tightening the arbor bolt can warp the blade or damage the motor shaft, leading to permanent vibration issues.
• Clear the Dust Port: Ensure the dust ejection port is clear. If sawdust builds up around the blade guard mechanism, it can create friction that slows the blade down.
• Match Blade to Material: Use a ripping blade for longitudinal cuts and a cross-cut blade for perpendicular cuts. Using a rip blade for cross-cutting creates excessive friction and that "slow" feeling.