Already have the book, but i knew what it was anyway... or i thought i did.
whipped motor out, checked big rubber motor housing thing, all looked fine - put it all back together - no howl 24 hours later but i did add a smear of silicone on the rubber housing nose.
Gave it a good floor test today but after 10 min it started howling again.
Bugger
Stripped motor out again, fitted a different motor bucket and side piece as well as the large rubber thing just for arguments sake ( i can't remember all the correct part names )
put it all back together and guess what ? howling ! fog horn...
so....stripped again - motor - i noticed it looked slightly different to the more common dc07 240 motor
this one then i noticed the part number YDK YV 511
fitted a new mtr299 instead and now ok.
Had a series of long floor tests and all is well. popped it's original cyclone assy on ( i use a test one for all machines instead of dirtying the machines washed ones ) and sounds partly blocked ! i know it's spotless inside and out...
However i remember jet washing this cyclone (a month ago) and when i removed top and pulled rod out there was a strange clump of something in there - emptied it out on the cut grass pile in garden and i have noticed a month later it's still there the same so not normal dust.
Gave it a poke and it feels muddy - and a blue / grey colour. Deep inside the cyclone unit still has it in there after looking with the scope so replaced the cyclone unit.
Another floor test - yep that sounds and feels better...
5 min later ....
clutch failed.... and what a noise...
I rebuild every clutch without fail, always have and always will, done hundreds over the years.
Had a great day today