Update… finally got round to fixing the cracked spindle on my WM16; was dubious about getting bearings off etc as didn't have a bench press, just a small bearing puller, anyhow set to yesterday. Getting the spindle cartridge out wasn't a major deal, just a matter of looking at the exploded drawing from the manual , just a case of covers off compress the spring with a screwdriver, remove the 'C' clip… careful you don't let go of the spring, once that's out the cartridge slides down out of the splined drive gear … for a fuller description of bearing replacement look on YouTube… there is a nice video by Hossmachine on bearing replacement on a Grizzly G0704 which is the nearest equivalent to the WM16/18 …
https://youtu.be/hP-XvbV7Pc4
Following the video my self for clarity I managed to get the spindle out using the small bearing puller set, plus some 10mm screwed rod I had. I didn't take too many pics of the procedure as I wanted to get on with it & get it of my 2doit list. What I noticed on the original spindle was a heat marks around the area of the bottom bearing… what is this I ask? the bearing didn't show any heat marks… was it some form of heat treatment in manufacture, maybe hardening treatment of the MT2 taper end…? anyhow the spindle is out, a good wash out with white spirits, dry off & check over for any signs of damage.
I refitted the new spindle with a pair of new taper roller bearings that I bought with new spindle, as per OEM, I didn't fit angular contact bearings ( ac ) as this would have meant messing about with shims to make up difference in outer race dimensions, a lot of YouTube videos show this but as part of upgrading to increase speed, which I wasn't planning on doing, so far I haven't needed to use higher than the 1200 rpm on the low range setting so no need for ac bearings. I have att. a couple of pics of the main procedure…
Bearing puller prep'…

Spindle pushed out of cartridge…

Heat marks on spindle, no signs of overheating on bearing…spindle heat treatment ?… the blue is OEM grease…

Old spindle out, new fitted, tools used…

I repacked new bearings with high temperature lithium based grease rated for 4000rpm, suitable for pump shafts, wheel bearings & other high temp' applications, all it needs now is to run in for a while & check for any over temperature rise indications on casing, then it should be good to go… fingers, toes & everything else crossed
George.