Burman Gearbox Lubrication

[CPR]

Hi. I’m soon to start rebuilding my Burman R Type 3 speed gearbox and I was wondering what form the lubrication should take. The Burman manual recommends Castrolease Medium. Radco recommends that 1/8th of a pint of EP90 oil should be added to the grease. I’ve Googled ‘Castrolease Medium’ but only ‘Old Stock’ comes up. As an equivalent what do other club members use in their Burman gearboxes?

[chris1]

Use semi-fluid grease, available from most classic lubrication people like Morris. Looks a bit like Swarfega and you don't get oil leaks!

[cottonjo]

I would not suggest using EP 90 it has chemicals in it that attack phosphor bronze. For years in my type R I mixed Straight 50 and grease. A messy task. Recently somebody suggested putting the grease in first, this reduces oil leaks . I now use a purpose made product, expensive but a litre will fill the box and top it up for years. I am in France at the moment and cannot remember the nam. Will tell you on my return.

[johnc]

Sounds sensible advice above.
I have never been sure why Burman didnt use thick oil like everyone else. I had got around to thinking that the grease lining, in-part, stops leaking. Is it also actually very clever in that the gears dont need to continually churn the oil, expending power, because 'tracks' form in the grease. However, I thought it might be an idea to periodically add a little bit of oil (not EP) on top, just to make sure nothing gets dry.

[cottonjo]

When I said fill the box, I meant of course only half fill it! Otherwise you will see lubrication oozing from the main shaft bearing. That bearing is available new for less than £10 and comes with a rubber seal on each side. Pick out and discard the seal on the inside and leave the one in place on the outside. The large bearing on the other end is scarce. I think you probably already know this, but there may be other readers who do not. I have some R parts spare if you need them .

[cottonjo]

When I said fill the box, I meant of course only half fill it! Otherwise you will see lubrication oozing from the main shaft bearing. That bearing is available new for less than £10 and comes with a rubber seal on each side. Pick out and discard the seal on the inside and leave the one in place on the outside. The large bearing on the other end is scarce. I think you probably already know this, but there may be other readers who do not. I have some R parts spare if you need them . I’ve just remembered it is “Penrite semi-fluid grease” I use.

[portboy]

Hi, Do you have a part number for the scarce bearing , i have access to a bearing supplier here in the valley with great range of older bearings in stock.
Tony

[cottonjo]

I think so, but am in France at the moment. I think that as the bearing was so large there was very little meat between the two bearings. A batch of bearings was made where the OD was ground to a smaller diameter. Somebody in Norfolk remanufactured some in the last few years. I will provide more information if you want on my return to the UK . Not for a week or so though.

[CPR]

Thanks gentlemen for all the advice. There’s a lot there to ponder over.
This Cotton is the first pre-war one I’ve owned, so its been a steep learning curve.
A Burman manual recommends 2 to 3oz of Castrolease Medium. When I took the gearbox apart the internals were only covered in oily grease. No excess.
Thanks for the offer of parts Cottonjo. I’ll bare if in mind but I’m not sure what I may need yet. The internals seem OK. The drive dogs are a little worn, but I’ve seen worse that have worked. I think I will put them back and see if it works OK. It’s clutch parts I need, but thats a subject for another thread.
The large mainshaft bearing at the clutch end is Hoffmann 5856. Which according to Hoffmann is a special bearing. So it’s not to surprising that it’s scarce. Fortunately both bearings seem OK.

[CPR]

Hi. This is a question for COTTONJO What was the straight 50 oil you use to mix with the Penrite Semi Fluid grease?
PS Hope you are enjoying your French trip.

[cottonjo]

Good old fashioned straight Miller SAE 50 . No synthetic or anything fancy.

[cottonjo]

With Penrite semifluid you do not add any oil though. Just take the gearbox cover off and squeeze the Penrite in, much less messy and exactly the right consistency.

[CPR]

Thanks for that COTTONJO. I'll order some today.

[chris1]

I know its another thread, but your mention of clutch parts reminds me that if you have no clutch, the taper shaft on the Burman gearbox will take a Triumph centre. This means you can fit a complete clutch which should be easier to find. A pre-unit one has single primary chain and looks similar to the Burman one. I have done this, it depends on your take on originality.

Chris

[CPR]

Hello Chris. To answer your post I think I will open a new thread.