Jonsered 490 Sprocket & Sprocket Bearing Replacement

Suitable Replacement Jonsered 490 Sprocket & Sprocket Bearing Parts

The sprocket transfers power from the centrifugal clutch attached to the crankshaft to the chain saw chain. The sprocket can be a spur sprocket or a two-piece floating rim sprocket. For further illustration, imagine the chain as a gear and the Jonsered 490 sprocket as a gear running together as a matched set. When a worn gear is replaced with a new gear but the matching gear is not replaced, the two will not mate properly. The irregularities between the two causes premature wear on the new sprocket and accelerates the wear on the old gear (chain). A sprocket that has been used with multiple chains becomes worn out and when a new chain is installed the scenario explained above causes unnecessary wear. The new chain on the old worn sprocket will stretch prematurely and accelerate the sprocket wear.

Performance Parts Supply sprockets and bearings meet or exceed OEM specifications for Jonsered 490 chainsaws and they cost less than OEM sprockets while maintaining excellent quality and durability. The sprocket rides on a sprocket bearing that can be a needle bearing or a bronze bearing bushing on older saws.

The spur sprocket is a one-time use sprocket as the chain will wear grooves in it as the chain is being driven by the sprocket teeth.

The two-piece floating drive rim sprocket is generally used on larger professional saws. The drive rim is made of tool steel for durability and wear. When the drive rim has had two chains worth of use (chains totally worn out), it can be replaced instead of replacing the whole sprocket (drum). This cuts the cost of sprocket replacement.