Author Topic: Gearbox grease  (Read 575 times)

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Mike Farmer

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Gearbox grease
« on: 11 February, 2021, 12:54:40 »
 :) :) :)

Hi.
In keeping with many of us my M20 has a stupid gearbox oil leak (bet you've never seen one of those then).
I spoke to a guy who made a differential for me and he uses grease, instead of oil, that should last a normal lifetime.
Yesterday I spoke with a local friend who is seriously into our oldies and he actually keeps this stuff on the shelf and uses it in old gearboxes, Quote " I have used it for years with no ill effects".
Its a case of drain the oil--melt the grease and pour the relevant amount into the box. With M20 he suggests taking off top plate to make pouring easier. Then, as it cools, it re-assumes it grease properties.
Because of its viscosity it doesn't "track" like ordinary grease does. So I'm seriously thinking of giving this a go.
Anyone with experience, I would like to hear about it.
Mike 8) 8) 8)

DAVE BRADY

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Re: Gearbox grease
« Reply #1 on: 11 February, 2021, 13:29:36 »
Hi Mike,

What is it?

Dave.

GLENN

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Re: Gearbox grease
« Reply #2 on: 11 February, 2021, 13:58:23 »
Hi Mike, As far as I know this is not recommended on the M20 gearbox as there are oilways from the gears to shafts that cannot be lubricated when grease is used, for example the sleeve gear.  I stripped a M20 gearbox a few years ago that had been filled with grease and there was a lot of heat scorching on the selector forks and selectors, and they were badly worn, so I wouldn't recommend it.  Plus all the bushes were excesively worn.  Just my opinion :) Glenn

DAVE BRADY

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Re: Gearbox grease
« Reply #3 on: 11 February, 2021, 14:07:34 »
Hi,

Heavy duty clearing saws and strimmers use a red grease in the angle drive in the head and this really is quite runny.  It is obviously so that tracks do not form and there is grease constantly on the gears.  However, I am not sure if this would find its away through the oilways in the pinions and shafts in a gear box.

Dave.

Mike Farmer

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Re: Gearbox grease
« Reply #4 on: 11 February, 2021, 15:53:26 »
 :) :) :)

I too had a problem with a greased box. But that was ordinary "axle grease". So I dont know. Next time I see him I'll ask the relevant questions posed here.

Mike 8) 8) 8)

Dean Southall

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Re: Gearbox grease
« Reply #5 on: 11 February, 2021, 20:04:44 »
It sounds very risky in a BSA gearbox. The small oil holes is one reason not to but I have also hear it said that the grease can form troughs so the gears are running in air.
I have found a plastic takeaway food tray deals with the problem ;)
However for a definitive answer answer from people who have been riding and building M20 for decades I'd ask the question on the WM20 Forum
http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&cmd=show
BSA: turning ordinary men into mechanics since 1910

DAVE BRADY

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Re: Gearbox grease
« Reply #6 on: 11 February, 2021, 21:42:43 »
Hi,

Oregon do the grease I mentioned above.  In fact two types.  One for the angle drive heads on brush cutters and strimmers so able to cope with the bevel gears.  The other a red fluid grease for the sprocket noses on chainsaws and chainsaw clutches.  It has other uses but even though very liquid for a grease it may not get in to the bushes of the gearbox pinions.

Dave. 

Bess

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Re: Gearbox grease
« Reply #7 on: 12 February, 2021, 09:11:54 »
Hi Mike,
            I would never contemplate using grease in the BSA gearbox.

I cant see how grease would migrate to the main gear bushes.
I wouldn't know how much grease to use, too little and the upper moving parts would be lub free, too much and the grease would churn and overheat.
Most bearing kits come with a prepacked bearing or a plastic packet with the correct amount of grease to use.
Grease doesn't cool the gears.

Google which grease to use in your motorbike gearbox, you'll probably get hundreds of oil options.

Best wishes...

TTJOHN

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Re: Gearbox grease
« Reply #8 on: 12 February, 2021, 19:23:57 »
I've actually got a tub of liquid grease, which I was going to use on one of my bikes but never got round to using it, the ariel CP gear boxes used grease and they were very sturdy boxes and I doubt if anyone had any problems with them, the liquid grease I bought is quite runny so I dare say that that would be okay for an M20 box.
When I worked for a catering equipment firm, we always used Marfac No2 grease which was quite thick in the food mixers and they ran for years with no problems but they were slightly different.

TTJohn

Bess

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Re: Gearbox grease
« Reply #9 on: 12 February, 2021, 20:08:08 »
Hi,
    The CP and BAP gearboxes used grease up to 1948 although many owners used 3 parts grease to 1 part oil. In 1948 an oil seal was introduced and SAE50 oil specified. Although Ariel recommended 50/50 mix of light oil and grease. By 1952 new boxes were designed and grease was replaced by oil.


Best wishes...