Warco spindle oil leak GH1322

Hi Guys,

Being driven to distraction with an oil leak from the spindle of my GH1322, which only shows at higher speeds and hoping someone has previously experienced this or can offer some guidance.
The oil is leaking from the contact between the collar and locking nuts securing the spindle as shown below.


This is a metal to metal fit and I cannot see how oil is prevented from doing this.


In desperation, I even tried changing the gasket on the end cap, but it made zero difference. You can even see the oil leaking on the garage floor

Schematic for reference.


Any advice/guidance gratefully received.

I had a steady but slow oil leak on my Warco BV20, also a geared head lathe, finally solved the problem I had filled the gearbox with fresh oil and topped it up till the level was at the top of the sight glass, when the oil level dropped to the middle of the sight glass the leaking stopped, it appeared it was only due to over filling. Dave W

The black cap with the labyrinth seal grooves appears to have an area to connect with a drain hole in the headstock - the parts list picture of the gasket shows a notch at the bottom that would clear such a drain hole.

So,first question - is there drain hole below the bearing seat to drain accumulated oil from the rear bearing back into the headstock ?

Second question - if there is a hole, is it clear ?

On the front spindle bearing cap on some larger lathes I have seen the labyrinth seal have multiple chambers, with the outer chambers drilled to allow coolant to flow outwards back to the coolant tray & the rear chambers drilled though into the headstock to drain the oil back into the sump.

Nigel B.

Hi Samsaranda,

The very same thing occurred to me as when I bought it last year, I did drain the oil and replaced it with the recommended amount of oil (can’t remember how much offhand)

This took the oil in the sight glass to the top line, but it’s now lost that much it’s on the bottom line so I am concerned that there is another problem. As I mentioned earlier, it only happens on 1255 or 2000 rpm, so I’m guessing it’s related to the amount of oil being thrown around by the gears its lubricating.

Only at high-speeds is consistent with over-filling, if that might have happened during maintenance. Or maybe Bearing 127 has an oil seal on the inside that's failed - replace bearing.

I don't have a gearhead lathe, but Samsaranda's post makes sense to me. Gearboxes don't like being overfilled.

Dave

Hi Nigel,
I honestly couldn’t say, but I do remember thinking why was there an extra hole in the gasket. Your suggestion makes perfect sense as if there is a return hole and it’s blocked, then the oil would rise in the cavity to the point where it would reach the spindle bore.
Thank you, I’ll strip it off tomorrow.

I eventually got round to stripping the end cap today, and there were indeed two drain holes at the base that would allow oil to return to the headstock. However, they were both clear! 🤦🏻‍♂️.


I tried it again, and the leak was present as normal. The only other thing I noticed was the collar had two grooves in which were at the bearing end. I reversed the collar so that the grooves were at the cap end and reassembled it.

I ran it at top speed for approx half an hour and there was no sign of a leak. I’m not entirely sure why this is the case, maybe the groove is helping to shed any oil that gets onto the spindle, but it appears to have made a difference.
I suppose only time will tell.
Thanks for all the help and suggestions

If vit needs saying, Labyrinth seals operate by flinging oil off the shaft into a housing which has a drain hole to return the oil to the sump / reservoir..

They have the advantage over lip seals of being frictionless, but work better as speed increases, because of the gretater centrifugal forces produced by the speed.

It looks as if you've fixed it, so that is good.

Howard

Edited By Howard Lewis on 19/08/2023 20:23:31

If you’ve fixed it - great. But have you checked for ventilation of the gear box? They need some form of ventilation to avoid any pressure as they heat up.