Tom Senior Spindle Disassembly

[Fred BennParticipant @fredbenn76496]

Hello all,

I am hoping to disassemble, clean, and regrease my spindle and rack for my Tom Senior Light Vertical milling machine.

Does anyone know how to remove the bearings from the spindle-rack assembly?

So far I have removed the Bearing Adjusting Screw (10), Bearing Locknut (9) and Bearing End Cap (3) from the Rack Quill (8). The assembly is different from the documentation shown below.

[Fred BennParticipant @fredbenn76496]

[Andrew Moyes 1Participant @andrewmoyes1]

From memory of when I rebuilt mine a few years ago – you are just left with the two bearings (items 4) which are a tight interference fit and the bearing spacer tube (item 7) which is a clearance fit. They should press out from either end as the bore of the quill is parallel throughout.

Andrew

[Jonathan RichardsParticipant @jonathanrichards78237]

There is a very helpful guide to rebuilding the milling head in MEW 258, which I relied on when I tackled a bearing change on mine. I can't recall much of the process now but I think the spindle does comes out downwards. I do know that I had to find an internal puller with small arms in order to shift the bearings that Andrew refers to above, because on mine the spacer tube precluded driving the bearings out from the opposite end(s). However, I believe that there are some alterations in the spindle assembly make up over the production life of the E-Type head, which may account for this discrepancy. Ultimately the new bearings made a substantial difference to the machine performance, so it was worth persevering. JR

[old martParticipant @oldmart]

Push down on the splined end of the spindle. The lower inner bearing will come out and the top bearing will remain in the quill. There are some drawings on the Denford Forum, this one shows the original MT2 spindle above an R8 modified one. There is a sleeve in the bore of the quill which can be removed. My R8 modification is broadly similar to the drawings shown. If you need new bearings, they are both the same size, and Timken imperial ones are easy to get from somewhere like Simply Bearings. Don't overpack the new grease, leave at least 50% air space. I used a common lithium high melting point grease used in cars and motorcycles.

There are some pictures in my photo album.

 

**LINK**

Edited By old mart on 08/06/2022 20:10:45

Edited By old mart on 08/06/2022 20:15:12

Edited By old mart on 08/06/2022 20:17:41

[old martParticipant @oldmart]

Your particular spindle has the splines rather than the drive key in a slot, the bush no.13 in the drawing is likely to be two needle roller bearings to support the front pulley. Otherwise the removal from the quill should be the same.

[duncan webster 1Participant @duncanwebster1]

I'd just regrease it and leave well alone. If it ain't broke don't fix it

[HopperParticipant @hopper]

If you are going to the trouble of pulling the bearings out, you might as well fit new good quality bearings while you are at it. They are cheap enough and designed to be a consumable item. As old as they are they probably have some wear in them so you might as well replace them now rather than later.

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