Noisy Lathe Gearbox

[Harry WilkesParticipant @harrywilkes58467]

Posted by Neil Wyatt on 06/02/2020 22:05:35:

I remember being advised to push a pair of old nylons through the filler hole of the noisy diff on my Cortina estate.

…

Thought it was sawdust one was supposed to use

[BazParticipant @baz89810]

No, sawdust goes into the engines sump, supposed to quieten the big ends!

[John MCParticipant @johnmc39344]

Don't know if its been mentioned, try some "climbing gear oil" (google Lucas climbing gear oil, other brands available).

I first heard about this type of oil in relation to the new version of the not very good Morgan three wheeler. They have a gear box that turns the drive through 90 degrees. Its often very noisy, climbing oil turns down the volume, a bit, apparently.

John

[SamsarandaParticipant @samsaranda]

John, the product you referred to was Wynns Friction Proofing, an oil additive that used to be on sale years ago, I never used it and I have no idea if it’s still available, I think modern lubricants negate the need for additives nowadays.
Dave W

[OldironParticipant @oldiron]

You can get a very good additive for quietening gearboxes in vehicles from Halfords or other motor shops & Ebay. It is Manual Gearbox Additive made by SLICK 50 costs £15 a small bottle. Easy to use and works a treat. I have used it in a Land Cruiser manual box and also in a farm elevator gearbox with excellent results.

regards

[John MCParticipant @johnmc39344]

Posted by Samsaranda on 08/02/2020 21:09:43:

John, the product you referred to was Wynns Friction Proofing, an oil additive that used to be on sale years ago, I never used it and I have no idea if it’s still available, I think modern lubricants negate the need for additives nowadays.
Dave W

No, its an oil rather than an additive. Just had a look at the Lucas Lube website, I see they no longer use the term "climbing oil", plenty more do, Plusco for instance.

John

Edited By John MC on 09/02/2020 08:00:05

[Dave HalfordParticipant @davehalford22513]

Posted by john fletcher 1 on 07/02/2020 10:15:44:

20 or more years ago when in Canada visiting relatives, they had a large American car to pull their very large caravan and boat. During the journey to a lake, the noise from the rear axle got really loud, we stopped at a garage (not many in such a remote area) the man said I'll pop you in some Winns. Well that Winns simply transformer the vehicle noise wise. I wonder if such stuff is available here in UK and would it be OK for a lathe gear box. Just a thought. John

Wynns or it's competitor brand STP was an engine oil additive back in the day for those with worn bearings or a Mini

Thick as treacle and just as stringy, don't use it in a modern engine with a Cat.

You can still get STP.

[egaParticipant @ega]

STP stood for "Scientifically treated petroleum".

[thaiguzziParticipant @thaiguzzi]

Posted by Harry Wilkes on 08/02/2020 15:33:07:

Posted by Neil Wyatt on 06/02/2020 22:05:35:

I remember being advised to push a pair of old nylons through the filler hole of the noisy diff on my Cortina estate.

…

Thought it was sawdust one was supposed to use

Bananas…

[Dave HalfordParticipant @davehalford22513]

Geoff,

I see wear on the top (spindle) gear. The chuck end of the teeth look narrower.

What you say makes me wonder if they put the oil window in too low as that gear would not be lubed enough by splash from the lower gears.

If Mgnbuk is right about that groove then I hope you levelled the lathe otherwise one of the head bearings has been running a little starved.

[Geoff CausonParticipant @geoffcauson89285]

Dave, you are correct. That's the reason I over-filled it, in an attempt to get that gearset to pick up.

I made a clear acrylic lid (as suggested by Nigel B) & filled it a bit more to get those gears lubed.

The groove around the housing is sealed by the gasket, so is not draining onto the main bearings.

It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm. The spindle gear shows damage, but it's not as bad as it looks in the photo. I just wonder what the mating gear looks like.

I investigated spare parts, the big one is listed but not the small one. I'm not brave enough yet to ask prices, no use just replacing one anyway.

Regards, Geoff.

 

Edited By Geoff Causon on 10/02/2020 05:26:43

[PeroParticipant @pero]

Quite right Thaiguzzi – definitely banana skins.

Also, I vaguely remember banana oil being used for something to do with model aeroplanes, so use in lathe gearboxes has to be a no brainer.

[not done it yetParticipant @notdoneityet]

If the gears were not splashing oil (the reason why you over-filled it) I would expect those top bearings are toast.

I have around ten gearboxes that have a dedicated oil-throwing gear (it idles all the time but is not part of the gearbox power transmission train). There is no way those boxes can starve top shaft bearings of lubrication.

Edited By not done it yet on 10/02/2020 07:15:48

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Geoff Causon on 10/02/2020 05:26:07:

[…]
It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm. The spindle gear shows damage, but it's not as bad as it looks in the photo. I just wonder what the mating gear looks like.

[…]

.

I hope you don’t mind, Geoff … I have straightened your photo a little, and cropped it to reduce the distractions:

It may be an illusion, but … the gear at top centre of the image looks to have damaged/worn teeth

MichaelG.

Edited By Michael Gilligan on 10/02/2020 07:26:58

[Dave HalfordParticipant @davehalford22513]

Posted by Geoff Causon on 10/02/2020 05:26:07:

Dave, you are correct. That's the reason I over-filled it, in an attempt to get that gearset to pick up.

I made a clear acrylic lid (as suggested by Nigel B) & filled it a bit more to get those gears lubed.

The groove around the housing is sealed by the gasket, so is not draining onto the main bearings.

It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm. The spindle gear shows damage, but it's not as bad as it looks in the photo. I just wonder what the mating gear looks like.

I investigated spare parts, the big one is listed but not the small one. I'm not brave enough yet to ask prices, no use just replacing one anyway.

Regards, Geoff.

Geoff,

Is that groove covered fully by the top plate?

The groove has to be there to either help prevent oil leaks (and be covered by the plate) or aid bearing lube as well if not covered by the plate (which means the gasket may be wrong.)

How far above the window is the oil level now? Hopefully below the lowest shaft bearing or it will leak quite a bit.

Have you tried a magnet in the oil?

[Russ BParticipant @russb]

One of the Lathe headstocks I'd worked on had a broke ridge line in the lid above the spindle which allowed oil to run off and drip on the gears below, the last of the ridges dripped into a reservoir cast above the nose bearing providing lube.

Another one of them (Colchester) had a steel fabricated reservoir on top that directed oil to the various parts, including the clutches hidden away at the back of the box.

It's for this reason that I don't use the Newton Tesla drive on my Myford 280 below 50%, as reducing the speed of the whole gearbox any further stops oil being thrown up from the bottom of the box to reach the necessary parts. I keep meaning to pop the case open and reprogram the pot to range from 50-150%

[Ex contributorParticipant @mgnbuk]

I would say that the gasket is not correct, but it would be interesting to see the underside of the lid to see if the groove is covered by that as well, or just by the gasket. There is no other obvious way for the spindle bearings to get reliably lubricated other than by the milled out grooves to deflect oil down the vertical casting faces & into the bearings – some might make its way into the rear bearing, but the spindle drive gear would tend to fling oil away from the front ?

It is worth checking that the splash does get everywhere & not just rely on a sight glass. I finished my apprenticeship at Boxfords at the time that the first of the "new" gear head lathes were being developed & the first production batch produced. Tests established that the headstock oil sight was initially positioned too low, as the level indicated didn't give adequate lubrication. As a batch of headstocks had already been machined, a sticker was made that was positioned next to the filling point that said (IIRC – though I do have one of the stickers on the toolbox I used at the time) "Fill to top of glass plus 1 pint". I wonder how many machines lost the sticker in operation & were subsequently operated with the oil level too low ?

Nigel B.

[Geoff CausonParticipant @geoffcauson89285]

Nigel, the gasket may be wrong. It's hand made & much wider than the lip on the lid. Strange, I bought the lathe new & have not replaced the gasket. A proper factory one would be die cut. I can't see clearly enough through my perspex lid to check if the modified one drains, but it can't hurt.

Like you, I suspect the sight glass is too low. The absence of any clever oil management features on the underside of the lid suggests the design /testing process was short. Also, the drain plug is too high, I had to make a vacuum sucker to drain the last half. It's all starting to add up.

Dave, The new oil level is 18mm above the middle of the sight glass, & the lowest shaft is about 15mm below the sight glass. That's well below the new level, but I'm not at all worried about leaks. Every drop of oil I put on the ways & cross slide ends up swimming with the swarf. I wouldn't notice a weep from the gearbox.

I like the idea of a catcher to direct more oil splash to the problem gears. There's plenty of room & the 2 center gear trains throw up lots of oil.

[HopperParticipant @hopper]

Your gasket mod looks like the way to go. The wide originsl gasket may have been handmade at the fsctory due to a shortage of ptoper parts etc. Chinese assembly methods have been known to be highly variable at times.

[not done it yetParticipant @notdoneityet]

It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm

Seems to me that it is time to stop worrying about that top gasket and start checking out bearings! Polishing s turd (with oil) will not make it smell any better.

[HopperParticipant @hopper]

Posted by not done it yet on 11/02/2020 08:37:49:

It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm

Seems to me that it is time to stop worrying about that top gasket and start checking out bearings! Polishing s turd (with oil) will not make it smell any better.

Lol. Back to the 3rd post in this thread.

[Dave HalfordParticipant @davehalford22513]

Posted by not done it yet on 11/02/2020 08:37:49:

It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm

Seems to me that it is time to stop worrying about that top gasket and start checking out bearings! Polishing s turd (with oil) will not make it smell any better.

Sometimes it best to find the cause before you repair the result, unless you like doing things twice.

[Chris MateParticipant @chrismate31303]

Hi, Geof was searching for similar problem I have with chinese lathe, here is my story.

Gearhed Lathe:160mm Chuck 330mm swing.
Problem-1: I am sure spindle bearing not getting oil they deserve.
Problem-2: I would say its noisy in higher gears.

I did the followingBefore)
1-I sucked out oil, put in diff 90 oil. Within 10 minutes it was out again. Motor not strong enough to pull it through that oil viscosity, and motor may burn out as well. I did this a year ago.

Last week:
2-I made a wooden frame, had a 6mm glass 21x22cm cut and fit & sealed on wood frame as a lid, this gave me great insight into what is going on, I could clearly see how and where it splahes depending on gear choice as weel as running in reverse(Big diff in each case).

3- I could see the spindle bearings with holes on top, not groves like yours, dont get oils fast enogh and well enough no doubt.

———Catch plates—–

4- I then went on the following endeavor with great success using the glass as giude to see.

5- I decided on a ISO 68 oil Fuchs freely availably for me 5L at Farm Strore. I mixed this with a dark blue marine grease wich in my opinion mixes well with this oil, not all greases mix well I tried, I like this. In my opinion this keeps the oil light and gives a softness to it wich I like. To test I pour it through a seringe 20mm(contraption=3 Seriges) to compare with ISO 68 and no difference….It flows to halfway, then drips, other oils like 30SAE behaves differently.

6-Ok so now I filled the gearbox higher, above glass to get a good throw on low speed gear (60 RPM).

—-New design………I am busy making "catchplates" from aliminium about 15mm wide.

7-I 1st made one to cross the top section with a bow in the middle, lets say 3 degrees to middle. This plate now catches the splashes, I grinded a groove in 3mm plate. You wont believe how the oil now flows towards the spindle bearing holes on bth sides. I even grinded short groves going sideays to direct overflows back in gearbox. This works perfect for all gears except the two lower speed gears, so I added more catch aliminium to catch from where the oil lands on glass, then drips down on catchplate and fow to spindle bearings. This worked, but not good and fast enough to my expectation, so I further improved this method on topside.

8-I then went further, seeing I can see everythinh happenning clearly. I went down in the greabox, fit a cross plate above a gear splashing, wanting to splash upwards. I construct this in such a way that it takes useseless splash from another gear below, let that oil flow left to this gear and shoot it upwards, not the catchplate catch it and I am very happy how fast the spindle gets oilflow in two lowest gears (60 & 90 rpm).

9-I am now going further, remeber I filled the gearbox a bit more oil, I would say 1/3rd. In higher gears motor stayed cool, I did not noticed drag, the gears are not wide to begin with, maybe that helped. This oil and grease combo is not "heavy", I liked that.

10-At moment I m busy with final design/idea to implement, and that is Drain-Reservoirs, to catch surplus oil in higher gears and "store" it, dripping away when the rush is over, keeping less oil in circulation momentararly, thats my theory in any case.

Note:Tomorrow I am going to extend "reservoir" on lower plate to store excess oil catched for upwards shooting gear. I will see if I can take a photo of the plot. So far I am very happy, and never thought I even do this.

Lathe is running quieter as well.

[Author]

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