What's new
What's new

How to determine the condition of bearings in a 10ee, and other questions

Removed the spindle bearings last night:
DSC01294.jpgDSC01297.jpgDSC01299.jpgDSC01301.jpgDSC01302.jpg
Heated up the bearing area then packed the spindle with crushed ice. Let it sit for 1-2 minutes and was able to get the bearing assembly off with about 6 hit to a hardwood board by dropping it from about 8-10 inches.
 
I have confirmed that the oil exit path for the forward bearing is via the channels in the retainer plate and thru the passage at 6 o'clock to the center reservoir.
DSC01310.jpgDSC01311.jpgDSC01314.jpgDSC01316.jpg
Any oil that gets through the labyrinth seal should drain via the forward weep hole.
 
My spacer has a hole at the bottom (6 o'clock) to allow the oil to fill that area.
DSC01309.jpgDSC01318.jpgDSC01321.jpg
The long slot is where the setscrew retains the spacer. My headstock has been apart at least once because they had initially installed the outer spacer backwards, you can see where the setscrew bit into the spacer in the second picture. If it's in backwards, the hole will be at the top and the center area will not fill to the sight glass level. When I remove the spindle the spacer was in the correct orientation.

The only un-answered question is the aft bearing of the pair. I have not looked at the retainer for it as yet, I will add info about it tomorrow.

My bearings are labelled: 20212 and both have db.t etched after the number.
 
I have found compatible Q20212 and QN20212 bearings available however, they are not sets but individual bearings. Who wants to pipe in on how bearing sets are 'matched'. Is the bore diameter the primary criteria for matching?
Both my db.t bearings have etch marks for the high point but the two bearings were not installed with those point either aligned or opposed. The high points were installed about 30 degrees from each other.
 
Had a look at the aft bearing of the 20212 pair. Splash from the central area between the two bearing exits directly into the central reservoir from between the inner and outer races.
 
I have found compatible Q20212 and QN20212 bearings available however, they are not sets but individual bearings. Who wants to pipe in on how bearing sets are 'matched'.

The size variation per pair of bearings for outer and inner diameters is measured to be less then 1/3rd of the total respective tolerance..

Essentially this means the ID and OD of a bearing is measured and then hand matched (or probably an automatic procedure in this day and age) to another bearing with a very close ID and OD size..
 
The size variation per pair of bearings for outer and inner diameters is measured to be less then 1/3rd of the total respective tolerance..

Essentially this means the ID and OD of a bearing is measured and then hand matched (or probably an automatic procedure in this day and age) to another bearing with a very close ID and OD size..
Why is that important?

Cal
 
Something I forgot to mention above: I found that my shift fork was loose however, the SHCS were tight. Not sure if it is a result of wear or if they are shoulder screws to intentionally leave a bit of slop. Will let you know once I have it apart.
 
Last edited:








 
Back
Top