Gearbox oil

[re5rotary]

Hi all now that Im getting close to being able to start my Commander after a complete rebuild of the bike I wondered what the current thoughts are on the best oil to use in the gearbox? Given the carnage I found inside my gearbox when I stripped it I want to give the replacement all the help I can to last regards Terry

[Clive603]

Both mine did pretty well on Castrol R. Not something folk normally consider as gear oil but castor based lubricants do have one of the highest pressure capabilities of any simple oil. Main issues are thermal as it goes off when it gets too hot, and environmental as it needs a pretty well sealed gearbox to keep out moisture. Got the idea from a friend who had experience assisting in the running of a supercharged sprinter with a habit of wrecking AMC and Norton gearboxes back in the late 1960's. Switching to Castrol R meant that they survived.

After finding worrying amounts of metallic debris on the magnetic drain plug at around 40,000 odd miles I inspected the box of my first Commander uncovering some very unhappy gears. Working for the Royal Armament Research and Development Establishment (and its successor organisations) meant I had access to to some real expertise (and some right pretend plonkers too) so it was only sensible to exploit the connections by having the parts inspected by appropriate folk in MoD labs. Certainly unimpressed with EP 140. Apparently what it really wanted was something uber specialised, second mortgage expensive, and only obtainable in 50 gallon lots by approved folk with the right headed notepaper. After being less than complimentary about the gear materials, hardening and spindly main shaft they agreed that R was well worth a try. Certainly made the change lighter. Lots less debris on the magnetic drain plug when I changed to my second Commander at around 80,000 miles.

Second one got R right from the start. When Richard did the Supreme Commander conversion on it at 95,000 miles or thereabouts I got him to send the innards off to Okerlion Balzers for a high performance coating to be applied. A bit spendy but I'm too old and short tempered for futzing around with fragile gearboxes. Getting Quaife to re-engineer the thing would have been more than a few sheckels too far.

Clive Foster

[johnbirchjar]

It's a pity that the hardening treatment for the gears and shafts at Okierlion Balzers was not made bit more public a few years back, 'cos I am sure that I am not alone in being willing to cough up a few quid to improve the scabby old Quaife g/box that are fitted to our Rotories,J.B.

[Clive603]

The Oerlikon Balzers treatment is a coating, not hardening. Can't say I really understand how it works but apparently that sort of thing is almost routine now for motorsport. Back then they were just getting serious about offering such services on a one off basis. Previously it was more industrial, batch processing and engineered in applications. Especially high tech defence stuff. Which was how I got to find out about it even though it was nothing to do with my speciality, IR systems (then).

Data on the relevant current offerings :- https://www.oerlikon.com/balzers/com/en ... t-engines/

If I recall the MoD lab peoples comments correctly (but that was pushing thirty years ago so plenty of time to get muddled!) the issue with our gearboxes is that the gears are over hardened to reduce wear from the things being seriously overloaded by rotary power. Over hardened gear surface is stiff, inflexible and relatively brittle so it tends crack and eventually spall off. Shaft deflection under load really doesn't help. My theory was that the coating ought to reduce or even prevent cracking so the hard surface stays where it should. Coating is supposed to reduce micro pitting and thats how cracks and spalling start. I imagine that if the boxes were designed now they would use slightly softer gears and rely on the coatings. But they would never be designed like that now anyway.

As I was spending the thick end of 9 grand on the Supreme upgrades and incidental overhaul it was worth making an effort to get the gearbox to last. Oerlikon Balzers don't do cheap tho'.

Clive

[re5rotary]

Hi Ok so if I give Castrol R a go what weight R30 or R40? regards Terry

[Clive603]

I used R40.

Probably best to put it on a regular 6,000 mile / once a year change schedule unless yours lives in a Bugatti standard heated motor house.

Back in those days mine were on regular commuting runs so new oil went in regularly. 25 miles each way. Usually doing 25,000 + a year with all the other running about. Not hanging around first thing either due to my disfunctional relationships with alarm clocks and mornings in general!

Clive

[johnbirchjar]

There was a company in Peterborough way back in the early '2000's that specialized in"One Off" gearboxes and they quoted me about 2 grand for a compleatly re-designed set of gears that would still fit in the original casing.
The guy that races the only Rotory Combination outfit (that I know of) gave me their name 'cos they made the gearbox for his racing outfit
They have now moved to Sussex,I last spoke to them about 6/7years ago and they told me to bring a g/box to them and they would have a look and quote me a price,I didn't take them up on there offer.I have there address somewhere if anybody is interested.J.B.

[Clive603]

Redesigned gears sounds interesting but probably lots more than 2 grand now! Wonder how they would deal with main shaft deflection which is the root cause of problems. Objectively its just too long and too thin for the loads involved.

I live in Sussex so its almost tempting to look them up if they are still going.

Clive

[johnbirchjar]

A compleate re-designed of the internals ?but as you say, a lot more than two grand now .I'll have a root round and see if I can find their phone number.J.B.

[johnbirchjar]

It's Nova Racing,01403711312,(over to you )

[Clive603]

Thanks John

Impressive looking website and list of products. Prices actually seem very reasonable for such (inevitably) limited production. However my reasonable might not be yours given where I used to work. Interpolating from prices on the site I'm guessing probable range of £3,000 - £3,500 including VAT for a complete one off set of innards.

Probably more realistic to just get replacements for the known to be iffy gears in a more modern material and get them coated like mine. If my "run on R" experience is typical and not personal, I'm known to be light on machinery, should be good for 100,000 miles or so.

(How in the name of all thats holy did they squeeze 6 gears into a Velo box! Can't see Bridgestone gearsets being a big seller, only time ever I saw one was when one of the other guys in 6 th form tried to sell me one as my first bike!)

Clive

[johnbirchjar]

I doubt it would be a viable proposition for me,(I had my 79th birthday a couple of weeks ago,)and am finding manovering the Classic (and the Deauvil) in and out of the garage getting a bit much ,so not sure how much longer I can keep on riding either bike,not going to give up biking though ,looking at "Twist and Goes" .J.B.

[Interpol2471]

JB ...REALLY

One thing that would worry me with R in the Rotary gearbox although it is a superb lubricant is that the gearbox may get hot enough to cause varnishing especially in an air cooled bike.
R is a fantastic lubricant I agree but once hot causes varnish to build up on all surfaces think I would stay on the standard route of gear oil etc.

[johnbirchjar]

Yep,like you, I have tried various transmission oils over the years, and one of the best was the one recommended for Harleys ,(well sticky,and a nice bright red colour,so's one can spot any leaks )
I am off to the wilds of Wales tomorrow(Hereford)for a bikers camping weekend(I'm ok riding the bikes,it's just when I have to manoeuvre them slowly,especially when loaded up with camping gear )ride safe,J.B.

[Assen]

In 1998 i had a conversation on gearboxes with Doug Hele at a meet from the Norton-Club. He advised me to add a little Molybdenum Disulfide to the gearbox-oils of all bikes with a separate clutch and starter solenoid. Of course i followed his advice. Molykote A is such a product that i use with great benefit. Lighter gearchanges and a big protection against wear.
I also have a BMW (from1960) that had allready been heavily damaged on the rearwheeldrive (gear and pignon?). Looked like cavitationdamage. Only option was to buy new gearwheels. At that time the gearwheels were sold out with BMW, so i had no choice than to put it all together again and ride the bike and wait on BMW. On Doug s advice (in 1998 wich i remembred)) i put some molybdenum disulfide with the gearoil to not damage the enddrive further. Long story short...this was 15 or more years ago and the reardrive still drives silent with no exessive play. There are no particals in the oil to see after an oilchange, so all is well. I will leave well allone...
I've also put a bit in the engineoil of this BMW, and the idlespeed increased....a sign of less friction in the engine..
Perhaps the above is of help...

Jannes

[johnbirchjar]

I may well try some of this Molythingey in the Honda(shaft drive and all that )next oil change.J.B.