The 445, 445E and 450E service and repair guide will help with changing the sprocket and or clutch. The sprocket needs replacing when worn after a lot of use, the same for a clutch. A Service Manual detailing the clutch and sprocket removal as well as complete chainsaw repair information is available to download. Also a Parts List, Operator Manual, and carburetor manual are also available to view or download as a PDF which can be read on any device or printed.
Time taken for medium skilled person to do this is about 20 minutes. The repair Covers the following Husqvarna chainsaw models:445, 445E and 450E.
Centrifugal clutch – removal
Remove the cylinder cover. Disengage the chain brake by pushing the kickback guard backward. Undo the bar nut and remove the clutch cover, bar, and chain. (see figure 13)
Disconnect the HT lead. Remove the spark plug and fit piston stop 502 54 15-01 (A) in its place. (see figure 14)
Unbolt the clutch using tool 502 54 16-03 (B) and a suitable socket or wrench. Turn the clutch clockwise to remove it. (see figure 15)
Secure the clutch in a vice as shown in the figure. Carefully release the clutch springs using circlip pliers
(C) (see figure 16)
Handle the clutch springs carefully. If they are opened up too much they could damage the saw.
Inspection and cleaning
Fig 16 Clean and inspect all parts carefully. If there are any cracks or other defects replace the damaged parts with new ones. Always use original parts.
- Check the thickness of the clutch shoes by using vernier calipers to measure the diameter of the clutch. If the diameter is less than 65 mm the clutch assembly must be replaced. (see figure 16)
Centrifugal clutch – refitting
Insert the clutch springs in the shoes using circlip pliers.
Screw the clutch (anti-clockwise) until it stops. Now tighten using tool 502 54 16-03 and a suitable socket wrench or combination spanner. Tightening torque min. 20 Nm.
Remove the piston stop. Fit the spark plug, tightening it to a torque of 20 Nm, then connect the HT lead.
- cylinder cover
- guide bar
- clutch cover
Sprocket and clutch replacement for Husqvarna 445 445e 450e chainsaws