Flail mower rotor bearing replacement

[Burnymill]

The non-pulley offside bearing has failed - screeching noise, heat and smoke! It's an 8 year old Jensen 1.25 metre for compact tractor - although I'm sure it's a generic Chinese machine - plenty of other makes look identical. Is it likely to be a simple replacement for a non-techy person like me? There are 4 bolts with central grease nipple. The bolts fit into a circular flange which supports the rotor. Looks like the entire rotor might need removing to get at this bearing? The pulley side looks daunting, can't see how to remove the belts - there is no tensioner. Photos show the external and internal bits. Any advice appreciated.

 

[Dave W]

Simple enough job.
remove belts and pulley. Then undo those 4 bolts either side and rotor will drop.
post some pictures of belts and pulley for advice on removal

 

[Burnymill]

Thank you Dave - photo of belts (mower is on its back):

 

[Dave W]

Thank you Dave - photo of belts (mower is on its back):

There must be a belt tensioner somewhere. Possibly on the other side under the tube that houses the driveshaft.

undo all the Allen key head bolts from bottom pulley. Once out they will reveal 2 or 3 threaded holes. Screw the same Allen key bolts into those holes. Tighten in turn until it splits that pulley and you can draw the centre boss out. Will be self explanatory after that

 

[Ladsdad]

Is this how it tensions

 

[Burnymill]

Thanks Dave and Ladsdad - I'll get a good look in the next couple of days - rain again so I'll have something to do inside!

 

[Dave W]

Is this how it tensions

No that is a part of the side wall that removes to let the rotor drop down

 

[Ladsdad]

No that is a part of the side wall that removes to let the rotor drop down

Ok makes sense.

 

[Burnymill]

Many thanks for help - re-assembled and tested, just waiting for new flails now. Found the belt tensioner near the drive shaft. Loosened it and gearbox bolts to allow the pulley to move, belts came off quite easily as did the rotor. Was struggling to remove the flange and bearing from the longer length of shaft at pulley side without a puller. Saw that the flange bolt holes just lined up with the edge of the rotor. Luckily I had long M12 coach bolts that I used to gradually screw in and push the flange off. Replacing the bearings wasn't too bad once I realised that the flanges had recessed sections, so just a matter of rotating the bearings and knock out/in via the recesses - still a very tight fit though. Re-fitting the rotor was a pain - lining up the holes as the flanges were hard against the sides. Really appreciate advice as a non-engineer.