# SM Utilathe 9" apron and quickchange gearbox disassemble, clean and reassemble



## calgaryguy (Mar 18, 2022)

So I got way ahead of myself and didnt take pics of the disassemble of the apron on my SM9

Here's where I am at. Lots of brake cleaner and lacquer thinner was used. I didnt need those brain cells anyways...

There was a significant amount of old black gunk coating everything. I should have taken pics of the parts pan after I spent 3 hours cleaning and inspecting. No chipped teeth, all gears spin freely on their shafts but no excessive wear, etc. Off to get some rtv to seal it back up...


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## calgaryguy (Mar 19, 2022)

Apron is back together and installed. I'll post a pic in a while. In the meantime I disassembled the Quickchange Gearbox for cleaning and inspection. Shafts are tight, no abnormal wear I can see.






Was about a 20-30 min job to take apart. I wish I had a large ultrasonic cleaner. I've been eyeing them at the vevor site for a while...


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## calgaryguy (Mar 19, 2022)

Cleaned and ready for reassemble, gotta wait till Monday and see if I can source some bearings:


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## PeterT (Mar 20, 2022)

calgaryguy said:


> I wish I had a large ultrasonic cleaner. I've been eyeing them at the vevor site for a while...


I dunno. Looks like you did a dang good cleaning job from here. I have a small 4-litre? ultrasonic cleaner. It for sure has its place in a shop. Really good for getting bitty bits of micro swarf & debris out of nooks & crannies, especially delicate parts. But it has limitations too. You can't use hydrocarbon based solvents as bath, has to be water based & then your choice of basically a water soluble detergent detergent. I've tried a few products but I find the so called environmentally friendly ones work the best for the cost. I think last time I used purple power. What I found is you have to be careful. The combination nice warm bath & additives can start an oxide discoloration on steel parts & aluminum parts can go from shiny to matte. This one particular 'lemon fresh' (water based) degreaser was bad for that. 

For baked on oily stuff I still prefer some kind of hydrocarbon & basically brushing action. For rust + munged parts I started messing around with some of the water based rust removers & actually work pretty good too so that might be step-1 in the future just because its easier to dispose. I guess I'm rambling on, but maybe test drive a smaller ultrasonic cleaner & see if it does what you want. They can get spendy as the volume increases.


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## calgaryguy (Mar 20, 2022)

PeterT said:


> I dunno. Looks like you did a dang good cleaning job from here. I have a small 4-litre? ultrasonic cleaner. It for sure has its place in a shop. Really good for getting bitty bits of micro swarf & debris out of nooks & crannies, especially delicate parts. But it has limitations too. You can't use hydrocarbon based solvents as bath, has to be water based & then your choice of basically a water soluble detergent detergent. I've tried a few products but I find the so called environmentally friendly ones work the best for the cost. I think last time I used purple power. What I found is you have to be careful. The combination nice warm bath & additives can start an oxide discoloration on steel parts & aluminum parts can go from shiny to matte. This one particular 'lemon fresh' (water based) degreaser was bad for that.
> 
> For baked on oily stuff I still prefer some kind of hydrocarbon & basically brushing action. For rust + munged parts I started messing around with some of the water based rust removers & actually work pretty good too so that might be step-1 in the future just because its easier to dispose. I guess I'm rambling on, but maybe test drive a smaller ultrasonic cleaner & see if it does what you want. They can get spendy as the volume increases.


I ended up using about 2L of Laquer thinner to do the tough cleaning. Its hell on my hands and nose. And expensive.

I didnt have any rust on this utilathe rebuild to deal with, but I have a 20L pail of Evaporust that I use to rusty things that has been worth EVERY penny I spent on it. Its chemistry magicks.


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## calgaryguy (Mar 20, 2022)

Made some progress today reassembling the QCGB. I need to try and pick up some bearings tomorrow at Transmission Supplies Limited in Calgary for the selector shaft.

THe most difficult thing was the 'stepped' or 'stacked' gears in the bottom of the pic below. They are VERY tricky to reassemble due to the splined shaft and tight tolerances they have to said shaft.


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## PeterT (Mar 20, 2022)

calgaryguy said:


> I ended up using about 2L of Laquer thinner to do the tough cleaning. Its hell on my hands and nose. And expensive.


Brave soul. I still maintain its one of the most effective solvents & best stuff for removing paint from expensive spray guns etc. Even after regular paint thinner or acetone, lacquer thinner will find some more residue the others didn't quite get. I knew it was effective when my nitrile? vinyl? gloves basically started evaporating off my hands. Need the tough rubber for that stuff. Normally I don't mind most smells but lacquer thinner I can't stand. Not sure if its the toluene or xylene or maybe something they put in, but it lingers for days.


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## calgaryguy (Mar 20, 2022)

I enjoy talking to my dead relatives when washing parts down with Lacquer thinner....


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## Degen (Mar 21, 2022)

Great cleaners overlooked.

Varsol (better solvent)
karosene (better lubrication properties)

Both soften and remove old dry grease and oils.  Biggest advantage is the still lubricate and prevent rust.

For certain applications I have one container with 4l of karosene and 250ml of Hobbs #9 mixed in.  Drop you piece in let it soak and scrub clean.

Disclaimer......Just remember the fire risks and the disposal of rags as they can self ignite, and the exposure issues.


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## Darren (Mar 21, 2022)

I've been doing some cleaning too, on my 10ee. Water based cleaners suck. They leave flash rust too, and weird staining. I ended up filling a garden sprayer that i normally use for pressure bleeding brakes with colored diesel fuel and soaking the whole machine. Not much fumes and the crud is melting away, a brushing with a nylon bristle brush helps bust up the thick stuff. After that, a round of water based cleaning gets the fuel off. Its slow going either way when there is 70 years of gunk in every nook and cranny.


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## terry_g (Mar 21, 2022)

I like Easy-Off oven cleaner for degreasing.
Just don't let it dry.


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## calgaryguy (Mar 21, 2022)

Degen said:


> Great cleaners overlooked.
> 
> karosene (better lubrication properties)


I actually started with 2L of kerosene in one of my parts pans. Let it sit for an hour and tried scrubbing with a brass brush. THe gunk was coming off but very slowly. Thats when I tried a little lacquer thinner on one gear and it immediately removed 95% of the gunk. 

And yes, mineral spirits, paint thinner, kerosene, et al have a self-combust risk. I usually put a bucket behind the garage half filled with water and throw rags/paper towels soaked in these liquids in it to minimize the fire risk.


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## calgaryguy (Mar 22, 2022)

terry_g said:


> I like Easy-Off oven cleaner for degreasing.
> Just don't let it dry.


Oh thats worth checking out, thanks for the suggestion.


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## calgaryguy (Mar 22, 2022)

Final pics. I was able to replace all the bearings shown in the earlier pic above EXCEPT the two smallest ones. The modern replacements with the same bearing number (stamped on the bearing itself) are 5/16" wide and not 1/4" like the ones in the machine and the position of the bearings doesnt allow for the 5/16th wide ones to fit.


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## Brent H (Mar 22, 2022)

@calgaryguy - are you talking the sintered bronze bushings?  Those you can reduce errrr……if you have a second lathe - ugh!  The paradox ..,, I digress


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## calgaryguy (Mar 22, 2022)

Brent H said:


> @calgaryguy - are you talking the sintered bronze bushings?  Those you can reduce errrr……if you have a second lathe - ugh!  The paradox ..,, I digress


If you look back above in the thread I have some bearings laid out on a shop towel - the two small diameter ones are the bearings I'm talking about.


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## Brent H (Mar 22, 2022)

Really???   Hmmmm - let me go and check the files on the 9” tear apart and send away.  - seems like those wee bastards are roller skate bearings - might have a cross reference


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## YYCHM (Mar 22, 2022)

Brent H said:


> Really???   Hmmmm - let me go and check the files on the 9” tear apart and send away.  - seems like those wee bastards are roller skate bearings - might have a cross reference



Didn't the whole QCGB get sent to a guy in the US?


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## calgaryguy (Mar 22, 2022)

So the originals were made by 'Nice' a bearing company in the US that has long ago been swallowed up by other bearing mfg'ers.

The stamped number (1602) on the bearing is still available, except its 5/16" wide now. There is a ** annotation in the online catalog the TSL guys showed me that says the current bearing number is 5/16" and not 1/4".

SKF, RBL and other common mfg'ers have the 1602 as a 5/16" width bearing.

There are 1/4" width available online, but I wanted to get my gearbox back together. I heated up some bike chain parrafin and soaked the small bearings in it and the reinstalled them.


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