What is the best transmission oil?

Anyone got ant more info on why people are using ATF?

What about these comments?
http://www.ajs-matchless.com/topic.asp? ... Title=Help

I just brought a new Norton labeled inspection plate for my gearbox on an Ebay impulse buy. When I removed the cover I found the gearbox had virtually no oil in it. Ive only had the Commando for 6 months and am still working out some ill conceived maintenance issues. It seems the previous owner forgot to tighten up the screws on the front cover when he rebuilt the gearbox a wile ago.
Glad I didnt find that out while I was skidding down the road after the thing seized.

Gearbox -

After trying everything (except ATF) listed in this thread, I personally have settled on Motul Gearbox Mineral 80/90. Black, stinky, and slick...my right foot tells me that this stuff brings the gear box to nothing short of dreamy. Simple click, click, click through the gears.

MOTUL DETAILS

Gearbox and differential lubricant Molybdenum bisulphide MOS2 reinforced Extreme pressure.

Specially recommended for noisy or/and loaded gearboxes. All mechanical transmission, synchronised or not synchronised gearboxes, gearbox/differential, transfer gearboxes and hypoïd differentials without limited slip system operating under shocks, heavy loads and low revolution speed or moderate loads and high revolution speed.

API GL4 and GL5 / MIL-L-2105D Extreme pressure lubricant for an efficient anti wear protection, reinforced with Molybdenum bisulphide to handle heavy loads. Stays in 90 grade after KRL 20 hours shear test as requested by SAE J306 Standard, July 1998 update Very high lubricating power which decreases friction and wear. 90 grade at hot temperature to provide outstanding oil film resistance at hot temperature and/or to reduce transmission noise. Suitable for any type of seal and yellow material used in gearboxes design. Anti-corrosion, Anti-foam.

Viscosity grade SAE J306 80W-90
Density at 15°C (59°F) ASTM D1298 0.902
Viscosity at 40°C (104°F) ASTM D445 164 mm²/s
Viscosity at 100°C (212°F) ASTM D445 21.7 mm²/s
Viscosity index VIE ASTM D2270 157
Flash point ASTM D92 198°C / 388°F
Pour point ASTM D97 -24°C / -11°F


To add to the engine oil portion of the discussion...the biggest thing is change it, along with a new filter regularly. Personally I run Valvoline VR1 50W - OR - if I happen to have it on hand Torco V/ST 50W.

Tankx for the Motul lead and ugh to Comez on turing and turning a new engine till it wears out, ugh. Implies if some fuel or ignition problem prevents early easy starting and run up, its a lost cause, ugh.

I now select lube in gearbox by how fast-long I intend to run it in lower gears, and consider Comstock's 10 min of WOT on max load as mild compared to what I enjoyed spanking sports bikes over the ton by staying over 6500 rpm for 20 to 45 min a heat for 45-60 miles in steeps. Only something as thin as ATF can get into the sleeve bushs to carry off heat to avoid filling their gap with gritty ceramics.
After ATF the bushes stayed fine and talk about thoughtless shifting ease,yum.

Changing often is the best policy as what is almost never mentioned in oil threads is most wear is from chemical corrosives that accumulate and etch surfaces just sitting up. This is one of the wonders of additives to extend oil changes longer.

The best oil for any engine is relative to operating conditions and how well the engine is likely to be maintained. If you are running a current model car and want to clock up quite a few miles between oil changes, then a synthetic oil conforming to manufacturers specs will be the best choice. On air cooled engines which run far hotter than modern water cooled car motors, the additive package in any oil is going to deteriorate a lot faster than in the cool running modern engines.

This linked to the fact that viscosity of non motorcycle specific synthetics, is a lot lower than the air cooled motors were designed to use, will mean synthetics will need changing more often, and are not likely to provide a great deal more protection than a high detergent diesel specific oil, which costs a lot less than synthetics, and can be changed frequently and will keep the inside of the motor very clean.

There are specific synthetics designed for motorcycle use, and those intended for modern 4T mx bikes, would very likely be ideal for anyone who has a particular wish to use a full synthetic in an old air cooled motor. These oils are also compatible with alcohol fuels, and oil dilution will not be a problem as it is if old fashioned castor based oils are being used.

Have had some experience of Mobil 1 being used in saloon car race motors, and it seemed that even with windage plates and sump baffling fitted, the very low viscosity appeared to have resulted in oil pick up being starved of oil during very hard cornering, which meant very limited lower end life.

I'm sticking with ATF or its thin synthetic relatives for surprising sports bikes in lower gears for most of an hour a go in Ms Peel but plain Jane Trixie gets the standard thick modern lubes that don't eat bronze bushes anymore. Even gear box lube should be changed out after run in, and time to time renewed d/t chemistry corrosives - though less prone that engine oil. Here's a primer on little discussed issue that may be a main reason surfaces go weak to rub away too fast.
http://www.mattituck.com/articles/engcorr.htm

I mostly use diesel grade oil in all my engines, mowers to motorcycles to truck. The zinc/phosphorous is about right, if ya can get the oil hot enough for those to adhere to surfaces and cook off moisture, while maintaining oil pressure. Commandos used to win endurance races - so rate your mechanical manhood by that eh. I'm not feeling very matured yet myself ok.

Sure glad this subject got brought up again so I can get all paranoid once more......

I've got about 45,000 miles on this speedo, more on the engine and transmission. No racing, but it is hard not to wind on the throttle to get that buzz that comes on after 4000 rpm. Quite a few miles were on 10W40 Valvoline and lately I've been using 20W50 Rotella. The gear box gets what ever 90W that goes in the H. Last summer I rode more or less 3700 miles to the INOA rally. If you did ride there, you know that some of the days were very hot on the way home. What more do you want out of an old bike ?

Your results may differ, but I still believe that you are over thinking this. Ride your bike. Change the oil(s). Fix it when it is broke. Repeat.

Greg

Wow Greg, my respects on such a long hot ride and bravery to use off the shelf oil a long time. I so want to have similar story - someday - maybe - please.
Spent last decade.2 learning downsides of Commandos and lubes, maybe, just maybe, next time out a charm?

gjr said:

I've got about 45,000 miles on this speedo, more on the engine and transmission. No racing, but it is hard not to wind on the throttle to get that buzz that comes on after 4000 rpm. Quite a few miles were on 10W40 Valvoline and lately I've been using 20W50 Rotella. The gear box gets what ever 90W that goes in the H. Last summer I rode more or less 3700 miles to the INOA rally. If you did ride there, you know that some of the days were very hot on the way home. What more do you want out of an old bike ?

Your results may differ, but I still believe that you are over thinking this. Ride your bike. Change the oil(s). Fix it when it is broke. Repeat.

Greg

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Agreed. Using a Valvoline 90W syn with no issues. I change it out every year or two due to storage and moisture in these parts. So Greg, was it as hot as Utah? Going to New York?

Hi folks. Don't get too hung up about "GL-5". The American Petroleum Institute (API) has defined the performance requirements for the majority of lubricants in common use. There are two primary specifications for gear (G) lube (L) which are GL-4 and GL-5 with GL-5 having the higher performance criteria. I would suspect the brand and not the spec. Had an interesting conversation with an engineer from a major synthetic oil manufacturer. I wanted to use their oil in my, then new, R1150. My owners manual (Canada) clearly specified not to use synthetic oil and the on line manual (USA) clearly specified not to use Mineral oil. His bottom line was that the base oil in any brand name lubricant was far less important than the chemistry of the additive packages. He also advised not to change to synthetic in older engines unless it was freshly rebuilt. End result - I stuck with dino oil for Canadian warranty reasons. Over the past 45 years I have personally used mainly Castrol, Shell and Gulf oils in my cars, bikes and boats and have yet to have a lubricant related failure. For what it is worth, synthetic oils, in general are less able than dino oils to emulsify water and keep it in suspension so I will never use a synthetic in a non-unit engine myself unless specified by the manufacturer. Sorry if this sounds like a rant. BTW, saw this on a Ducati website a few years ago;"If it makes you feel better to by expensive oil, go ahead. Otherwise it is perfectly ok to use what the manual calls for."

Anecdotal personal experience: I've used Mobil 1 Synthetic Gear Oil in my gearboxes for years. One gearbox is in my street Commando, the other in the Manx which is only used on the track. I have had one gearbox failure on the Manx, that being due to failure of the sleeve gear bushing which became galled to the point of almost seizing up (coming off the track I thought the brakes were binding). Looked like a lubrication failure to me. The bushing looked as if it had run dry despite the box being properly filled. Several paddock advisors (much like Navy Sea Lawyers), indicated that I should never use Gear Oil in a Norton gearbox, it being too thick to adequately lubricate the sleeve gear bushing. I've had no failures in my street gearbox.

One of my racing friends who runs a brace of Manx's runs ATF. However, I've seen him experience at least two gearbox failures, with one of those boxes being of the very expensive six speed variety. I think it difficult to attribute the failures to lubrication, but I'm still not comfortable running something that thin.

Okkie Dokie then that settles the issue Steve, period, done, throw in the ole towel on it, there is no way any liquid lube can get into the sleeve bushes when spun up as they are above oil level and sling out any lube trying to get in. If any place in Norton needs a pressure feed this is it. Your report backs up my experience, > to give some idea how much fun I had on my street bike running away from hot shots where it mattered most. Cog wise 3rd seems to be my weak set or teeth.

On Ms Peel I will have the surfaces cryogentic'd, dry friction coated, run ATF and replace at first hint of clutch basket wobble.

MexicoMike said:

Hmm, makes one wonder how Norton Commandos ran for many thousands of miles originally when there was no such thing as synthetic oil and they were generally ridden a lot harder by us young guys than they generally are now by us old guys...

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I thoroughly agree.