stihl FS 460 gear box issue

[Aspen51]

I have a stihl fs 460 brush cutter and I have replaced the gear bearings as they failed. I have replaced them and the gear box works but when i put the blade back on and tighten the nyloc bolt the gears jam up and i cant move the gear box. I can take the gear box apart but it does the same thing when i put it back together. Any ideas on how to fix this? Cheers

[spudulike]

Take a look at the IPL below and make sure the components are in the correct order. It sounds like on securing the blade, the gears are forced further together than they should be. Check part "4" as it may be in the incorrect position. Possibly screws "16" are too long and not original?

 

Edited Sunday at 21:15 by spudulike

[GarethM]

Was it just the bearings you replaced or did you change 2&3/6&7.

 

Plus make sure it's well greased, as per above ensure the 4 washer is in the correct place as when you tighten the blade it pulls everything downwards seizing it against the housing cover.

 

Playing devil's advocate I'd also ask if the original bearings just seized or grenaded as that may have damaged the teeth on the gear wheel and head as they may operate but under load they have to mesh perfectly.