Thread: what oil?

Ok, so all my oils are changed and if Im not mistaken, I beleive the oil from the rear spindle is seeping into the center gearbox, any ideas on what is going on here? Thanks

That seems standard with some 10EEs - mine leaks down the front bearing sump unless I leave the #2 camlock on the top. Then it takes a couple of months to leak down.

Originally Posted by KnoLimitz

Ok, so all my oils are changed and if Im not mistaken, I beleive the oil from the rear spindle is seeping into the center gearbox, any ideas on what is going on here? Thanks

It's nice to know that people read my posts . I already explained this in post #25 of this thread, complete with diagram...

Cal

Sorry Cal, just spaced out, I'll look now

Originally Posted by KnoLimitz

Found this post, thought it was helpful!

Originally Posted by Mad Machinist
The named series were Mobil's lowest cost general purpose gear and bearing oils. They would be the first choice for a big old machine that looses a lot of oil. But it doesn't matter. I talked with Mobil last week and they are completely discontinuing the named series and recommend using the 20 series as a direct replacement. Probably not that many simple old machines out there anymore. I think the 20 series additives make it suitable for hydraulic systems which would have more sliding metal components and tighter tolerances than an old gearbox. I think Chevron Regal R&O oils are the same as the Mobil named series if that is what you want.

Link to Mad Machinist post from 12-10-2009: What is the difference between Mobil DTE Light and Mobile DTE 24?

There's some very bad information here; I want to set the record straight.

1. The DTE Named Series IS NOT Mobil’s “lowest cost” oil. In fact DTE Light is about 10% more expensive than DTE 24, even in 55 gallon drums. Both oils are made from turbine quality feed stock. They differ primarily in the additives used.
2. The DTE Names Series HAS NOT been discontinued. It was available in December 2009 when Mad Machinist posted this and it is available today. AFIK, Mobil has no plans to discontinue it.
3. Mobil DOES NOT recommend DTE 24 as a direct replacement for DTE Light. (Call their lube tech support line at 1-800-443-9966 and ask them yourself.)

Possibly he’s confused on the last two points. The Vactra Named Series was discontinued and the DTE Named Series is the recommended replacement.

The DTE 20 series, which includes DTE 24, is formulated as hydraulic oil. The main purpose of hydraulic oil is to move things via hydraulic force, be it the cylinder on a backhoe or an industrial robot. According to the Exxon-Mobil website, the 20 series “…were developed in conjunction with the major builders to meet the stringent requirements of severe hydraulic systems using high pressure, high output pumps as well as handling the critical requirements of other hydraulic system components such as close clearance servo-valves and the high accuracy numerically controlled (NC) machine tools.” The two companies they mention by name are Denison (a Parker Company) and Vickers (an Eaton Company); both market high end hydraulic cylinders, servo valves, etc. These components use special alloys that require protection by special additives in the oil. The NC machine tools they referr to here are probably things like industrial robots, not CNC machining centers.

Hydraulic oil has to operate in very different conditions than gear oil and has special additives to handle the service. For example, a retracting hydraulic cylinder carries minute amounts of contaminants back into the cylinder where it can contaminate the oil; special additives work to neutralize the contamination. Hydraulic systems usually have filters to remove particles from the oil and this typically means that additives are used to suspend the particles until they reach the filter.

Additives aren’t necessarily compatible with one another and may work at cross purposes. For example, the additives in DTE 24 inhibit it's ability to separate from water; DTE Light, on the other hand, has excellent water separation properties.

I’m sure DTE 24 is dandy for what it’s designed to do: operate under pressure and protect internal hydraulic components with exotic metallurgy. It has special anti-wear additives designed to meet those needs.

DTE Light is better at other things: better anti-foaming, much better water separation, better rust and oxidation protection. Foaming can definitely be a problem with a high speed spindle bearing, i.e. 10EE running at 4000 RPM.

For a machine tool spindle with no circulating pump and filter to clean the oil, the last thing you want is oil designed to suspend particles; you want the particles to settle harmlessly to the bottom of the sump. You also want water to separate completely. You don’t want water and debris constantly circulating though precision bearings.

data sheets:
Mobil DTE Oil Named Series
Mobil DTE 20 Series

Cal

I read this thread to find out what oil is required for my 1943 Round Dial Monarch 10EE. Here's a summary of what I used, plus some other information:

Oils for Round Dial Monarch 10EE

reservoir oil drain fill
------------------- ---------------- ------------------- -------------------------
center headstock Mobil DTE heavy medium pipe - left rear headstock - center top
rear bearing Mobil DTE light drain thru sight glass headstock - left near top
front bearing Mobil DTE light drain thru sight glass headstock - right near top
gearbox Mobil DTE heavy medium pipe - left front large cap on top of pulley shaft
backgear on DC motor Mobil DTE heavy medium screw plug - bottom screw plug - top
apron Mobil Vactra #2 right near bottom left near top
tailstock base Mobil Vactra #2 * not needed front right base
tailstock quill Mobil DTE heavy medium not needed top of tailstock

* = manual and Monarch call for Mobil DTE heavy medium

Mobil DTE heavy medium is available (from Grainger) in 1 gallon cans. Light and Vactra #2 come in 5 gallon buckets. Some are available on eBay in smaller containers.

Machine lubricant cross-reference:
http://www.basstool.com/PDF/literatu...0Reference.pdf

Flushing (from an email by Cal Haines)

Flush with kerosene or diesel. Use only fresh kerosene to flush the spindle bearings, run it in the top and let it drain out the bottom. You want to avoid washing the sludge from the bottom of the reservoir into the bearings. You can get a rubber cork from ACE Hardware and put a drain tube near the bottom edge to keep from getting kerosene all down the front of your lathe.

For the headstock, take off the top cover and do a few fill and drain cycles until the kerosene is coming out clean. Then you can start flushing with a hose and a length of tubing as a nozzle, leaving the drain open. I use a helper of work a simple recirculating pump. It's a good idea to use an automotive inline fuel filter to keep from washing fine debris back over the gears, etc.

Depending on what you find in the headstock, you may want to remove the dial from the quick-change gearbox so that you can do a hose flush of it as well.

It's always a good idea to pull the apron and saddle on a machine with an unknown maintenance history. You can flush the apron then and also check the pump and lube lines.

Sorry about the lack of formatting for the table. Here's a cleaner version. I've added capacities.

Nice table.

I think Vactra is a better choice for the tailstock quill than DTE heavy medium.

Cal