How often should I change the oil in my geared head metal lathe, and what oil should you use for the gears in the headstock? What’s the best way or how should I change the oil in the headstock of my metal lathe? We have a lot of customers that buy our metal lathe owner’s manuals looking for the answers to these questions. Some of the metal lathe manuals cover lubrication and oiling really well, some don’t hardly cover it at all, and some have outdated information. I’m going to share some of the tips, tricks and techniques we use in our shop with our geared head metal lathes that can be applied to most geared metal lathes in any shop, but, as always, I highly recommend a instruction manual.
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Starting with some information about oiling your metal lathe is usually better than having none, and before you take my word on anything, you should always cross reference it with what your manual recommends. Plus, your lathe manual will hopefully include a chart with all the different points you should lubricate, and each model has it’s own points that don’t like to get dry.
How Often Do You Change the Oil in Your Metal Lathe Headstock?
I was doing research before I wrote this article on oiling your lathe, and I read through our huge selection of operator manuals from different manufacturers that cover intervals for how often you should change the oil in a geared head metal lathe. As you can imagine the time varies from one metal lathe company to another. A lot of them state that the oil should be changed out every 6 months, and a lot simply say keep the oil up to the fill line or top it off repeatedly.
“We never change the oil in the heads of our metal lathes in our shop”
Unless you are operating your geared head metal lathe 8 hours a day 7 days a week, you probably don’t need to drain your oil every 6 months in your metal lathe no matter what the model is. Honestly, we never change the oil in the heads of our metal lathes in our shop. My father and I are the only ones operating them, and we aware of the conditions of how they are being used. If your lathe is in an industrial environment, where you can’t keep track of the use by the different operators, it might not be a bad idea to change the oil once a year while you perform general maintenance on the lathe.
There are times when you do need to change the oil:
- When we purchase a brand new or used lathe. Obviously you don’t know the history of a used lathe, but even a brand new lathe should be drained and cleaned out. You really can’t buy a new lathe made in the USA anymore. More than likely it is coming from Asia. We work 12 miles from Grizzly Industrial’s Springfield, MO showroom and warehouse. I’ve gone through hundreds of their new machines, and they all have metal filings and cast iron dust inside of them. Nothing against Asian machines, but just always make sure you clean them out before you use them.
- When something goes “Clink-Clank”. If things aren’t sounding right inside your geared head metal lathe headstock, and you regrettably have to find some wrenches to take the cover off to see what is creating your new noise, you may need to change the oil in your headstock. It’s a lot easier to work on the inside of the headstock of your metal lathe without a pool of oil that you keep pulling your wrenches or flashlight out of.
How to Drain & Flush the Lubricant & Oil Out of a Geared Head Metal Lathe?
Most geared head metal lathes have a threaded plug at the bottom of the headstock. Generally they seem to be on the side opposite spindle, and hidden by the gear cover. These are usually just threaded holes in the casting without any sort of drain, funnel, or trough to keep the oil in your headstock from getting all over your metal lathe bench or chip pan when you open it. I’ve seen all sorts of methods to easily and cleanly collect the oil from the headstock. My personal favorite is the taped bag method.
Below is a Grizzly G4003 12″ x 36″ Gear-Head, Cam Lock Spindle, Gap Bed Metal Lathe that I was fixing up. A shaft that holds a gear was broken off at the warehouse, and I needed to replace it to get the metal lathe going again. So I needed to drain the oil in the headstock to replace this part.
The plug for the oil was on the bottom of the casting of the headstock on the opposite side of the main spindle. What I did was tape a one gallon Ziploc right below the plug of the oil drain. Once I take a wrench and unscrew the plug the oil runs right down the side of the headstock of the metal lathe into the bag. You need to make sure you use a large enough bag to capture all the oil in the headstock. If for some reason you misjudge it, you can always put the plug in and replace the bag, then repeat.
I find this to be the simple, and easiest process to capture the draining oil from a geared head metal lathe. Sometimes there may be a lot of particles or sludge in your headstock, and you may wish to flush it out. Before you start flushing out your heastock there are a few things that you should keep in mind. If’ it’s not very dirty, I would recommend not flushing the headstock out. Usually you have a bunch of open bearings inside, and it is better that the particles or sludge stay at the bottom or crevasses where they belong then risk getting a particle inside a bearing. It can only take one particle to mess up a good bearing at the stress and tension they are under.
If you do feel like your headstock should be flushed out, then this is the procedure I recommend. I would try to vacuum out everything and get in there with a brush to keep the particles out of the bearings. Then I would try a mixture of kerosene and oil. To flush out the headstock. If it is really bad, then you may need to use a water hose with pressure.
If you use water, you are going to want to let everything dry for a day or so. Then after the kerosene and oil flush, and letting it dry, you will want to turn every shaft individually by hand. We are trying to see if there is any dirt or particles in the bearings. So are going to want to do this slowly and with your most sensitivity. You are trying to feel for any hesitation in the bearings. The Standard Modern metal lathe manuals actually recommend you fill the headstock with an oil and kerosene mixture, and run the lathe without a load for a few minutes. When you are finished draining the oil, flushing and servicing your metal lathe, then you just need to fill it back up with the correct oil.
What Oil or Lubricant Should I Put in my Gear Headed Metal Lathe Headstock?
I always recommend that you check the manual of your lathe and go by what the manufacturer states. We have manuals here if you need one. But sometimes, if you have an old lathe, you get an old manual that has outdated information. Generally for most people that have a personal or small shop, I recommend non-detergent Mobil DTE Heavy/Medium 20 Sae Grade Circulating Machine Oil. This will suite most lathes just fine. Some metal lathe manuals I read do recommend 30 weight, but unless you are running your lathe 8 hours a day, it probably doesn’t matter a whole lot if you aren’t sure. You can pick up a gallon of this oil at Enco. I recommend getting on their mailing list, and waiting for a free shipping and percentage off sales. Either weight of oil should be fine, but you need to make sure your oil is non-detergent.
Detergent Vs Non-Detergent Oil for a Metal Lathe or Machine
You need to use non-detergent oil in almost every machine. What’s the difference? Detergent oils were introduced in the 1950’s. They have additives in them that are designed to suspend and trap particles. Detergent oils are what you put into a modern car with a oil filter. The idea is the suspension carries the particles to the filter, which is replaceable.
Non-detergent oils are just straight oil, and they let all the particles sink to the bottom. These are commonly used in small engines without filters like two stroke engines, lawnmowers, tractors, etc.. Since the headstock of our geared head metal lathe doesn’t have a filter, we want all the particles to sink to the bottom, and stay out of the gears and bearings.
Please let me know if you have any other recommendations, questions, or ideas about changing the oil your geared head metal lathe in the comments below.