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Thiel Duplex 159 oil sight glass not working

magnusrm

Plastic
Joined
Sep 14, 2020
Hi. Ive been doing some lubrication work on my new Thiel 159 duplex that I just bought while Im waiting for the electrician to get me power.

The old oil in the gear boxes were pretty dark, and the main gear box seemed to be empty when I drained it until I put a cable tie up in the drain plug. Then some coagulated oil / particles loosened and "normal" dark oil started flowing out. I waited an hour for it to fully drain before I filled up the specified 4L oil.

On the lower gear box, the oil sight glass works fine, and has a white background. The upper sight glass has a dark background and it doesnt seem like oil is entering on the backside of the glass.

Upper gearbox (main) after 4L new oil:
IMG_20200928_143834 — ImgBB

Lower gearbox after 2L new oil:
IMG-20200928-143846 — ImgBB

Should I try to fix this, or just do the yearly oil change as normal and measure the used oil and new oil. I am doing a oil change after a couple of weeks now, since it has been standing still for so long.
 
Thanks guys. When I drained the old oil, it still looked like this. Im pretty sure its completely dry on the back side, and it might have a small inlet / outlet that is clogged. Looks like I have to make a small tool to open it up.
 
The lower gearbox is fairly well sealed and so the oil tends to stay clean for a long time. The upper gearbox is not really sealed at the top and it is fairly easy for contamination to enter. I would consider running the mill for a while and then changing the upper gearbox oil again. Better still would be to take the cover off (drain first!) and clean it all out.

The sight glasses do get dirty and difficult to see through. You can take them out to clean, but I would suggest making a special tool to unscrew the rim - obviously don't use a punch. I made a tool for the sight glass on my 159 boring head and I think the gearbox glasses are similar or the same. See below:

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Take care when cleaning the sight glass inside. The paint showing the level can rub off if you are too heavy handed.
 
The lower gearbox is fairly well sealed and so the oil tends to stay clean for a long time. The upper gearbox is not really sealed at the top and it is fairly easy for contamination to enter. I would consider running the mill for a while and then changing the upper gearbox oil again. Better still would be to take the cover off (drain first!) and clean it all out.

The sight glasses do get dirty and difficult to see through. You can take them out to clean, but I would suggest making a special tool to unscrew the rim - obviously don't use a punch. I made a tool for the sight glass on my 159 boring head and I think the gearbox glasses are similar or the same. See below:

Take care when cleaning the sight glass inside. The paint showing the level can rub off if you are too heavy handed.

No need to reinvent the wheel
You have tools for that
Adjustable pin wrench



Peter
 

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That was my first thought, but the pins on those wrenches are too big. I could have made new pins and pressed them in, but it was just as easy to make a special tool.
 
Not sure how you got on with this but I had the same issue. I drained the oil and replaced it with new. Whilst filling it up I shined a power torch/flashlight on the sight glass and was able to see the oil level much easier.
 








 
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