This is a continuation of the thread "Millrite MVI spindle bearings may need replacement" first posted on 31 July 2010.
I now have the spindle out of the quill and the taper roller bearings off the quill. I made (from a cast iron pipe fitting) a special pusher to avoid crushing the grease slinger, and (lacking a press) used a piece of 1/2-13 allthread passed through the drawbar hole to generate the needed force. Greasing the spindle just ahead of the sliding bearing race also helped.
The taper roller bearings are not in that bad condition, given that the grease had turned into some kind of chalky cake. However, the absence of grease had allowed coolant to enter and corrode the bearing "cup" (the outer race) of the lower bearing assembly in a few places. I assume that the area weakened by corrosion will soon fail. The rollers are not yet clean enough to tell if they have been compromised, but one assumes that there has been damage.
It is not obvious how one would grease these bearings without removing spindle from quill (which isn't that hard, but still). I have heard of people instead using DTE24 or heavier hydraulic oil fed in through the plug in the side of the quill, and letting it drip out of the bottom of the quill. This may be a better approach. What experience do people have with this?
For the record, the two outer races ("cups") are each Timken 19268; and thetwo assemblies of inner races ("cones"), rollers, and cages are each Timken 19150. The stated ID of a 19150 cone is 1.5000".
The quill shaft is about 0.0011" larger than the stated cone ID, so it was a light press fit. As others have noted , this cripples the running preload adjustment by turning a ring nut on the spindle, and press fits are too hard to get exactly correct.
Is there a standard solution? I'm tempted to polish the spindle shaft down until the (new?) bearings are a (hand) push fit. Has anyone done this?