Determining when to replace ball bearings

[belairbob]

I m working on the final drive on my A replacing seals and checking bearings. The bearings feel tight and smooth turning to me but how do you guys decide when to keep and when to replace? It s been years since the tractor was driven but I remember it did have a whine although not excessive. The gear oil is black and thick. Thanks!

 

[Janicholson]

A radial load ball bearing must have some clearance, but a bigish bearing like bull gear axle bearings should have less then .004 inch looseness. Smaller bearing
have less down to precision bearings that may have .0005. Jim

 

[riverbend]

It is a matter of feel. Get a new bearing and see how it feels. Clean the old grease out of the old bearing, put in a drop of oil and turn it trying to feel for rough spots. If I can convince myself there aren't any and they aren't too loose, I'll reuse the bearing. Sometimes if I know that the bearings have eaten a load of grit, I just change them.

 

[used red MN]

Maybe this is beyond obvious, clean the bearing
spotless clean with solvent and blow dry with air. Find
a good light or the sun. Hold the bearing so you are
looking across the outer race between to of the balls.
Slowly turn it one complete turn. Look for any flaw
pitting or flaking. Repeat viewing the inner race. If it
passes this test then it is acceptable to check for play
and roughness. The acceptable play has been covered.
And I agree with a bit of clean oil it should turn
smoothly.

 

[belairbob]

Thanks for the replies! I have been cleaning them and turning to see if rough spots. On one of the differential bearings thats still attached if I hold the top and bottom and try to rock there is a slight movement. I guess this is the looseness Jim spoke to?
I ll also remove and check the other ways y all have given me.
Thanks!

 

[jimtrs]

Common for the transmission to whine. Wear on the gears. Most used gear usually whines the most. Nice to find one that doesn't.

 

[rustred]

nope. not at all.

 

[rustred]

guess i will throw in my way of checking them . clean as good as new in solvent . couple drops of oil on the balls and rotate by hand and
listen for any clicks or feel of rough spots, plus inspect he ball track for wear. if it compares to a new brg. reuse it. when they tell u
200.00 for a new brg. then your old ones can start looking pretty good! they are slow turning brg's. and should last as long as anything else
in the power train. plus many times these old brg.s will have double the amount of smaller balls. and last a long time compared to some cheap
jobber brg. that will work.

 

[belairbob]

I appreciate all the ideas! I have already spent a lot on bearings but dont want to miss one that is questionable. As a side note so far I have purchased 6 bearings that are from 5 different countries! Two are in Timken boxes marked China but the bearings have no markings. The other 4 are in caseih boxes marked as made in Italy, Bulgaria, Argentina and USA. Three bearings marked SKF and one Bower. Go figure!

 

[rustred]

i would reuse the old usa brg. before using the china ones.

 

[belairbob]

(quoted from post at 08:11:09 08/20/22) i would reuse the old usa brg. before using the china ones.

es I should have done my research. I saw Timken and assumed quality.