Myford ML10 (later model) lubrication

Hello everyone,

I'm not a complete beginner, but close enough. I have a Myford ML10 (Speed 10) lathe - it has the later taper roller bearings rather than the plain bearing headstock.

My question is, what to lubricate the bearing with?

The manual says to use lithium grease on a taper roller bearing machine, or oil on the plain bearing types. At the weekend, I tried to buy some appropriate grease from Myford, but the fellow said to just use the oil. I pointed out to him that the manual said to use grease, but he just shrugged and said that the manual was written 50 years ago, and was out of date as everyone uses oil these days.

I'm not keen on that idea. I think if the manual said to use grease, even 50 years ago, that would be because grease is better for the taper roller bearings. The manual might be from a few years ago, but so is my lathe.

Anyway, so I'd be keen to hear what other folks use to lubricate a taper roller bearing ML10, and how often (differing advice there too!).

Many thanks

Steve

Hello Steve,

I use lithium based grease from Castrol, but just about all the manufacturers will have a lithium grease in their range. Try Halfords as a start, but you can get it from motor factors, usually much cheaper too!

The first time I tried lubricating the bearings I rather overdid it and got grease all over the inside of the cover! Not good for the belt, that is for sure. I now open the cover and grease until I can see signs of movement around the rear roller. As to how often .......... well depends how much you use it. I would guess a good greasing would last about a 100 hours running. So it doesn't have to be done often. Although I am open to correction on this.

Andrew.

As a comment/query

I always thought that one should not put too much grease in bearings as it created heat.

Is that correct?

If one looks at sealed bearings there is very little grease in the bearing

Hi Sam,

You are correct, too much grease will make the bearings hot. It has been discussed on this forum, here's a link to what SKF says.

Thor

We had a bearing heat discussion!! recently. Look at SKF with reference to your bearing number it will give you an indication of grease amount. Bearing should be greased with enough to cover the surfaces, usually about a third of the free space volume. Adding more will only cause heat generation.

Lithium or moly (or teflon) grease will be fine. Oil is OK ... if you have an oiler to keep them lubricated!

I've been told it's best to fill about 25% of the space in the bearing to avoid overheating and 'ploughing'.

Neil

In my opinion, I would rather have too much grease than too little! But I bow to every ones knowledge on this!

Much more to the point how often would one grease? With the bearings in an ML10, how do you know how much grease you have put in the bearings. All very well saying 25% of the space etc when you cannot see how much you have put in. Correct me if I am wrong, but I can't see the grease quantity in my my ML10 bearings.

As to heat generation, I am not bothered about that. With lithium grease, the grease will run out of the bearing when hot, so it is more or less self limiting. I know this happens, because I see signs of grease coming out of the bearings for maybe the first hour or so of running, after greasing.

I am NOT trying to be argumentative, merely quoting the observations I have made on my ML10.

Regards,

Andrew.

There is a specific time period for greasing the ML10 bearings, something like 10 hours running and then one pump of the grease gun.

I do not recommend pumping until grease appears, as you found it will come out in quantities and clart everything up.

I could check but I have no wish to go outside at the moment as the temperature is minus 2.5 C.

Clive

When I've regreased bearings in the distant past, if they were 'open ' bearings I used to coat the balls/rollers inner / outer race tracks 'till all was completely coated then put a finger end full of grease in the bottom 1/4 - 1/3rd of ball / roller cage, that was usually sufficient to meet needs. Nowadays majority of bearings are sealed for life behind a metal / polymer / rubber shield so 'old one out new one in'...

George

I may stand to be corrected here & you my be perfectly right, but grease does not go "Thin" when hot. So I would suggest that if grease is being expelled it is initially due to too much in the bearing. This is what is making the bearing hot which cannot be good for the bearing if over expansion occurs. Agreed some bearings may be designed to run at a certain high temperature.

Re " runny" grease I wanted some " thin " grease so I put some high speed machine grease from one of my moulding machines ( forget the grade) on a tin lid & held it over a blow lamp. Nothing changed as far as the grease was concerned. It certainly did not thin out. This is not conclusive of course but does suggest that general machine grease would stay at a consistent consistency

Taper roller bearings behave differently to ball bearings where grease is concerned - ball bearings "churn" excess grease & this generates heat, whereas taper roller bearings have a "pumping" action that moves grease though the bearing & expels the excess. IIRC the grease is moved from the large end of the rollers to the small end.

SKF don't recommend using moly or other additives in grease for bearings, just normal lithium soap grease.

Nigel B

I have found from experience that Lithium grease does lose a lot of viscosity when hot. I am not certain about other types of grease. However lithium based grease can do this. I have even opened cans that have got very warm in summer and found a liquid on the surface. I am not sure it is supposed to do this, but several different cans have shown this effect over the years!

Maybe an experienced lubrication engineer can comment on this?

Andrew.

Edited By Andrew Tinsley on 27/01/2017 14:28:00

Taper roller bearings in an ML10 headstock are nothing special. They are just the same as the wheel bearings on millions of cars and trucks around the world. Any wheelbearing grease from a car parts store will do the job more than adequately.

+1 on don't pump grease in until you see it come out around the spindle. It can ruin the bearings and serves no good purpose whatsoever. That's why the manufacturers tell you not to do it. I've seen it done on a set of HVAC blower fan bearings on a 4-inch diamter shaft where the engineer in charge insisted on pumping the pillow block full of grease once a month until grease came out around the felt seals. They had to replace the bearings every six months or so and could not work out why. Looking for stray electrical currents, dynamically balancing the impeller etc and even increasing the greasing schedule to weekly!. Normally such bearings have 25 to 50 per cent grease fill in the pillow block and last for years and years and years.

Clive's suggestion of one pump of the grease gun every 10 hours' runtime would be about right, if not a bit on the over-lubed side.

If you are in any doubt, open up a brand new sealed bearing and you will find the tiniest skerrick of grease in there, a mere smear. They run for decades like that. Look at how many 20 year old cars still have the original sealed alternator bearings running just fine.

Edited By Hopper on 28/01/2017 02:30:37

Edited By Hopper on 28/01/2017 02:31:59

Edited By Hopper on 28/01/2017 02:32:47

Hello Hopper,

I don't mind in the least at being pulled up for duff information. The problem I have got, is that a lot of the advice appears to be somewhat conflicting. As I said before, there is no way I know of, to determine how much grease there is in an ML10 bearing, So whatever you put in, is pure guesswork. You go on to say, quite rightly, that there are thousands of cars that run for many years with a sealed bearing in the alternator. Is the implication that it is fine to do the same for the ML10 bearing? As to frequency of greasing, if I adhered to the one shot every 10 hours, from my Wanner, then I would rapidly fill up the bearing, which is precisely what you counsel against. I do bow to better knowledge and will not in future fill up the bearings until grease comes out, I am guilty of bad practice.

I am still very curious as to the behaviour of lithium grease. There is no doubt that under very hot summer conditions, in a shed, the grease appears to start melting and there is liquid in the can. I assumed wrongly, that if I overfilled the bearing, then it would self correct, by melting out. I have seen this "melting" behaviour with various makes of lithium grease, but never with any other type. Maybe what I am seeing is not due to a melting process. Does anyone know what is going on here and has anyone else ever seen this curious behaviour?

Thanks,

Andrew.

Look at how many 20 year old cars still have the original sealed alternator bearings running just fine.

And how many vehicle alternators use taper roller bearings ?

You are comparing apples & pears here - vehicle wheel bearings these days are sealed for life angluar contact ball bearings, alternators are ball bearings, many plummer blocks are ball bearings - as I said earlier, over greasing ball bearings is not a good idea. But taper roller bearings work a little differently - well, that is what the Timken Design manual said when I had to consult it for the design of a machine tool spindle bearing arrangement some years ago. I don't have access to that manual any more, but do recall the comments about taper roller bearings having a "pumping" action on the lubricant & I believe that is the reason for recommending a periodic regreasing on taper roller bearings that may not be required on ball bearings.

Nigel B

Just to confound you all, I will quote from the hand book of the ML10 and this also applies to the Speed 10.

Headstock bearings front and rear taper rollor brg, Lubricate every 4 to 6 months with Lithium grease until it oozes out of the bearing.. This on page 6 of the hand book.

Clive

The phenomenon you have observed is 'static bleed' where some of the base oil is released by the thickening agents. This and 'dynamic bleed' - which can cause problems in bearings are explained nicely in this article...

**LINK**

Thank you David!

That seems to explain what I have seen with lithium grease. Thank goodness there is a rational explanation for the phenomena!

Clive,

That will put the cat amongst the pigeons! So the manufacturers seem to care not how much the lathe is used in a 6 month period! Also they don't seem to mind if the grease oozes out.

Maybe the answer is that it doesn't really matter what you do as long as you occasionally remember to grease the little perishers. But stop when you see movement, otherwise you get a very greasy belt! Come to think, maybe I should read the manufacturers handbook, no excuse here as I do have it!

As to the front bearing, God only knows how you see grease oozing out of that one, as it is completely shrouded from prying eyes!

Thanks all for an interesting discussion, at least I now know why you get the liquid formation in the lithium grease.

Thanks again,

Andrew.

No. The implication in this convenient example is that roller and ball bearings in general do not need to be packed full of large amounts of grease in order to function correctly and last for many years. They are rolling elements and need very minimal lubrication.

Edited By Hopper on 29/01/2017 02:05:19

LOL, when all else fails, read the destructions.

Thinking about it further, it would seem there must be no proper seals on the ML10 bearings if grease can ooze out. (I'm not familiar with the ML10). So a) filling the bearings full of grease will not result in damaging pressure building up inside, the grease being free to ooze out in  best British engineering tradition. And  b) pumping grease in will flush out swarf and dirt that has gotten into the bearings due to the el cheapo lack of seals on the bearings. Just like on the Myford rubbish felt bed wiper system made up for by flushing out with the oil gun.

But in this day and age, wouldn't synthetic grease work better than lithium?

Edited By Hopper on 29/01/2017 02:00:59