Stihl Guide Bar Maintenance

The underside of the guide bar experiences the most wear during cutting. For guide bars without a nose sprocket (Duromatic bars), the nose area is particularly stressed. Before attaching the guide bar and chain to the chainsaw:

• Clean the oil inlet holes and the bar groove using the groove cleaner on the filing gauge.
• Check the groove depth.
• Inspect the bar rails for burrs and deburr if necessary.
• When bucking, fine sawdust should be pulled from the cut instead of coarse, thick chips.
• Flip the bar over to ensure even wear on both sides.

Using four saw chains with two chain sprockets and one guide bar in rotation is ideal - this is known as the 4-2-1 principle.

Groove depth

The bar groove shallows as the rail wears. Maintaining a medium depth is crucial to prevent the drive link tangs from scraping along the groove bottom. If they do, the tangs wear quickly, and the cutters and tie straps will not ride properly on the bar rails.

Checking groove depth

Rollomatic guide bars with sprocket nose

Use the scale (groove cleaner) on a filing gauge to measure the groove depth on both the top and bottom of the guide bar.

Duromatic guide bars without sprocket nose

Use the scale (groove cleaner) on a filing gauge to check the groove depth along its entire length.

Replace the guide bar if the measured depth is below the specified minimum!

Deburring bar rails

Burrs form on the outer edges of the bar rails as they wear.

This burr can be removed with a flat file or the Stihl guide bar dressing tool.

If the left and right bar rails wear unevenly due to an improperly sharpened chain, this can be levelled with the Stihl guide bar dressing tool, provided the difference isn't too great.

Maintaining the required minimum groove depth is essential after levelling the rails.

For serious damage to the guide bar, consult your local Stihl servicing dealer for assistance.

Wear on a guide bar

A saw chain that is too loosely tensioned for an extended period can negatively affect the guide bar's condition.

If these issues are spotted early, corrective measures can be taken to reduce wear. Regular checks for abnormal wear on the guide bar are essential.

Checking nose sprocket of Rollomatic guide bar

There must be clearance (a) between the chain and bar nose. If there’s no clearance, and the chain contacts the bar nose, it indicates worn nose sprocket teeth or a damaged nose sprocket bearing.

Worn guide bar rails

There must be clearance (a) between the chain and bar nose. If there’s no clearance, and the chain contacts the bar nose, it indicates worn nose sprocket teeth or a damaged nose sprocket bearing.

Left: Evenly worn bar rails, minimum depth has been reached, normal