Hi, I just had to go through the process of changing spindle bearings on my pre 1995 Acra AM-2V manual mill with step pully head.
I had .005" of play just from pushing and pulling on the spindle by hand.
There was a complete lack of information online so I am putting my notes here. Hopefully they will help someone in the future.
The general technique is just like a Bridgeport: Removing a Spindle on a Bridgeport Head - YouTube
Remove draw bar and draw bar washer from the top
Remove set screw in the back of the quill
Remove spindle nose (left hand thread) using 0-3" face pin spanner wrench
On mine the spindle went down just enough to see 90% of the lowest bearing and wouldn't move anymore.
I found the quill stop nut was blocking its movement.
Remove the quill stop nut assembly completely (similar to a bridgeport).
Lower bearings are 7207 0AIR P4 BEARIND, I paid $275 for the pair from Acra (since they are close to me and I needed them asap)
Upper bearing is a 6206, $25 from Acra
Spindle nose is $60 from Acra (could have reused it, but I boogered the holes)
They had all the parts in stock
I opted for sealed bearings because it seems like the spindle oil dissolved all the grease and left the bearings under lubricated.
This machine also sat for 5 years, so that could also be part of the problem...
Here is the exact NSK bearing part number I received from Acra for the lower spindle bearings: 7207A5TYNSYMP4
Anyways, hope this helps someone.
I had .005" of play just from pushing and pulling on the spindle by hand.
There was a complete lack of information online so I am putting my notes here. Hopefully they will help someone in the future.
The general technique is just like a Bridgeport: Removing a Spindle on a Bridgeport Head - YouTube
Remove draw bar and draw bar washer from the top
Remove set screw in the back of the quill
Remove spindle nose (left hand thread) using 0-3" face pin spanner wrench
I found this very difficult. Soaking it in penetrating oil, using a torch, and finally a punch I got it off
Lock the spindle all the way up, use a brass punch and hammer to push the spindle down. Doesn't take much force.On mine the spindle went down just enough to see 90% of the lowest bearing and wouldn't move anymore.
I found the quill stop nut was blocking its movement.
Remove the quill stop nut assembly completely (similar to a bridgeport).
Lower bearings are 7207 0AIR P4 BEARIND, I paid $275 for the pair from Acra (since they are close to me and I needed them asap)
Upper bearing is a 6206, $25 from Acra
Spindle nose is $60 from Acra (could have reused it, but I boogered the holes)
They had all the parts in stock
I opted for sealed bearings because it seems like the spindle oil dissolved all the grease and left the bearings under lubricated.
This machine also sat for 5 years, so that could also be part of the problem...
Here is the exact NSK bearing part number I received from Acra for the lower spindle bearings: 7207A5TYNSYMP4
Anyways, hope this helps someone.
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