Rebuild questions for an 87 Mark V power head

[P89DC]

After using my SS all weekend long it's developing a howl. Not sure which bearing, it's coming from the belt side of the powerhead.

I think I'll just tear it down and replace all the bearings/belts and set it up for another 30 years which will put me just south of 87....

In 1998 I replaced the bearings on my AO Smith motor. The rear bearing was shielded (and fried). My local bearing supplier sold me two sealed replacement bearings. Was that a mistake? Should I have used a shield bearing in the rear? It's still working well....

Why wouldn't I use sealed bearings for all the replacements in my powerhead?

Should I drop the motor out or do the "ship in a bottle" routine? My hands are large/ex-large glove-wise and it's an older one with the smaller access port.

How does my speed changer look?

Any other things I need to know/have before I dive in?

Thanks,
Eric

[JPG]

Howl????

First thing I would do is blow that fine dust off the speed control parts.

THEN apply some oil to the control sheave bearing(the one in the pix with the loop).

Let it soak in.

Then see if the 'howl' has changed.

IMO, sealed bearings make sense. But then none that I have replaced have 30 years run time(yet).

A better way to get oil in the control sheave bearing is to profusely get oil into the hole in the control sheave, raise to vertical and let the oil migrate to the bearing overnight.(thank you Bill)

Large hands - get a 'zoom spout' oiler.

[P89DC]

Anyone able to answer these other questions?

Should I drop the motor out or do the "ship in a bottle" routine? My hands are large/ex-large glove-wise and it's an older one with the smaller access port.

How does my speed changer look?

Any other things I need to know/have before I dive in?

[algale]

I've never dropped the motor. But I have zoom spout oiler.

I think there's too much sawdust to say anything about the condition of the speed changer from that photo. After you blow it out and oil it, you'll know if it needs other work by how easily it changes speeds when the motor is running.

You should consider watching the old Sawdust Session videos on the Shopsmith website. There are several showing everything from routine oiling to changing the speed control to doing a near total tear down and rebuild on a headstock.

Jacob Anderson has some good maintenance videos on Youtube that will also show how to do this and other maintenance jobs.

[P89DC]

Before I got to my original headstock I purchased a non-functioning 1980 unit off of CL. I decided to drop the motor, now that I have it's clear that's the way to go.

While I'm inside I'm replacing all seven OEM shielded bearings with sealed bearings (single bearing quill). Can't repair the idler shaft so I bought a new unit with sealed bearings from ebay vendor "bandsaw-tire-warehouse". New belts, bearings, replaced the damaged switch and speed control knob. The sheaves were frozen too. Interesting way to learn about headstocks!

[rcplaneguy]

As part of your diagnosis, walk the belt off the motor, then listen to the motor alone. Helps identify exactly what is making the howl.

[P89DC]

I've had the power head since 1987 (30 years), I'd like to use it another 30 years when I'll be in my mid-80's. It's unlikely any single bearing will make it 60 years without needing replacing. There's only 7 or 8 bearings in a power head (depending on the quill and including the motor bearings). What's the big deal about just replacing all of them? Esp now while it's easy for me to do it.

I'm more in the mode of OWWM.org. While rebuilding an old machine it's a fool's errand to try and cheap out by not replacing all the old shielded cartridge bearings with modern sealed versions.

[JPG]

I do not think replacing 30 yr old bearings is a 'big deal'. I think doing so when it is already disassembled is just plain common sense. I would keep the ones removed that seem OK just for possible future need.