Suitable solvent for flushing my mill's gearbox

[jgedde]

I have my RF45 clone apart to replace a leaky seal. The gearbox is filled with sand, cast iron particles, and other assorted garbage. What's a low volatility, low flammability, low oder solvent suitable for flushing out the dirt, oil and gunk?

I'm thinking diesel is a comparatively low cost idea. What do you all think?

tHANKS!
jOHN

 

[Rbeckett]

Mineral spirits if you can find any. They used to sell it in Home Depot in a 1 gallon metal can, but I haven't bought any lately so I couldn't tell you if they still have it or not. Diesel smells, spirits is pretty good solvent wise and low odor. Just a thought.
Bob

 

[jgedde]

Mineral spirits if you can find any. They used to sell it in Home Depot in a 1 gallon metal can, but I haven't bought any lately so I couldn't tell you if they still have it or not. Diesel smells, spirits is pretty good solvent wise and low odor. Just a thought.
Bob

Good idea Bob! Home Depot had it in stock at $14/gallon. Slight odor, but wonderful at getting the crud out of my mill! With the amount of casting particles (mostly cast iron) that were in there, a strong magnet will be placed in the bottom of the housing to catch any stuff I missed.

Now I see why they don't recommend detergent oils!

Cheers!
John

 

[arvidj]

I used kerosene ... also available at Home Depot or Mills Fleet Farm or Menards or ... to clean out the gear box and apron on my lathe. I then used this ... http://www.harborfreight.com/brake-fluid-bleeder-92924.html ... to suck it back out again. I pulled the black adapter off the end of the bleeder tube and then used duct tape to attach the bleeder tube to a paint stick. That way I could push the bleeder tube where ever I needed to in the bottom of the gearbox to vacuum it all up.

A cheap chip brush ... http://www.harborfreight.com/1-inch-chip-brush-39627.html ... or ... http://www.harborfreight.com/pack-of-36-1-inch-industrial-grade-chip-brushes-4181.html ... more duct tape and another paint stick allowed me to make a very long handled brush to ... well ... do what you do with a brush and kerosene.

The only thing I had to watch out for was the bleeder tank getting full. It will not stop sucking when the tank gets full, it simply turns into a very poor spray gun at that point. Yes, I am sure you can figure out how I came by this knowledge.

 

[Old Iron]

I also used kerosene in both my mills, Filled the gear box and the knee ran them for 5 minuted drained and added new oil.

Paul

 

[jgedde]

John,

Please post some pictures of the insides of your mill. I also need to tear apart my RF-45 clone to fix a leak and I'd sure like to see what I'm up against.

Thanks,
Ed

Edit: I forgot to say that I used kerosene for cleaning out my lathe and mill gear boxes.

Ed, I'm sorry to say that I did not read your post in time and my mill is back together. She works, is leak free, and seems to work a bit better with more spindle bearing preload)

Disassembly is no great shakes when you know ahead of time what's in there (I didn't). Basically it goes like this for seal replacement:

0) Drain gearbox.
1) Remove Motor
2) Remove snap ring on spindle bearing (on top). Not sure you really need to do this... I did.
3) Remove gear selection knobs
4) Remove front panel
5) Remove power switch (if equipped on side of mil like my Precision Matthews).
6) Remove six cover screws
7) Remove cover, some of the gear shafts may come off with the cover. Reinstall them into the bottom of the gearbox when the time comes.
8) If equipped with power down feed, remove power down feed on/off knob. If not go to step 11
9) Remove two screws on outside of housing holding the cam wheel shaft for PDF engane/disenage.
10) Remove power down feed driven gear.
11) Now you can get at the seal holder. Remove the three screws that hold it on.
12) Remove and replace seals (see below)
13) Flush the gunk out with mineral spirits.
13) Check spindle bearings and readjust preload if required (I set 'em a bit tighter). There is a tanged lock washer under the preload nut. I just reused it. Be sure to lap the bottom of the preload nut as it burrs up really easy. Now is the ideal time to repack the spindle bearings (or replace them). Mine were fine, although the grease was well diluted with gearbox oil that leaked out. I ust cleaned 'em and repacked them with grease.
14) Assembly is the reverse of the above.
15) Refill with suitable lube (ISO-68 Hydraulic oil or otherwise, just not detergent oil).

The seals are 35X45X10mm and two are required. My local power transmission outfit only had good quality seals in 7mm thickness. So, I simply fabricated a 6mm spacer to make up the difference between 10mm x2 and 7mm x 2. The spacer is 6061 aluminum, 44.9mm in diameter, 37.8 mm ID, and 6mm thick.

Alsoi check out this link for pictures of the insides. My PM-45MPDF is VERY similar.

http://www.graetech.com/index_files/Page975.htm

Any questions, just ask... It's still fresh in my mind and senility hasn't yet set in.

An interesting bit of trivia is that all of the internal breaings are sealed bearings. Considering the amount of particulate matter that was in there, I can understand why... I popped off the seals, cleaned out the bearings, and cleaned again, and again 'til they ran smooth, relubed, and replaced the seals.

One more thing: I used Permatex Ultra Black RTV gasket maker to seal the top cover and the seal "plate" inside the gearbox.
John

 

[rmsflorida]

I flush the head stock of my Hendy lathe with mineral spirits/kerosene a hundred years ago..
I place a magnet in the head stock in a out of the way place.
I was surprised in what I found on that magnet the next time I changed that oil..Mostly a mud like substance .
All the cavitation of the oil flushed out particles of metals and stuck to the magnet.
Two weeks ago I remember what I did with that Hendy ..

So when I change the oil in my Lodge & Shipley "Power Turn" even that it has a filter oil system I still put a magnet in that head stock..

Robbie

 

[OlBadger]

Magnet in gearbox is a superb idea, particularly now there are some cheap but incredibly powerful ones around, but and I expect many will go 'duh!' at such a stupidly obvious point, make sure it sits well away from steel gears and if possible epoxy it to a service trap or drain plug. Whilst flushing with kerosene does the job beautifully, it may also leave some unwanted 'thinning' of the new oil, I tend to use a commercial vehicle flushing agent or flushing oil after the 'paraffin' (I am Brtish after all) and the final oil, it just seems to provide that little bit extra of cleaning and clears the nasties from the nooks and crannies.