Does anyone know the properties of BMWs name brand 75W140 synthetic gear lube? I just drained some from a recently rebuilt trans where the tech who built it used the BMW gear lube. It is very different than what I am used to. Does anyone know how it differs from other synthetic gear lubricants?

i would not waste any time to that

just use it

Castrol MTX 75W140
MOTUL Gear FF Competition 75W140

zonenfeile wrote: i would not waste any time to that

just use it

Castrol MTX 75W140
MOTUL Gear FF Competition 75W140

My ususal gear lube is Mobil 1 synthetic 75W140. I was just curious if there was anything special about the BMW stuff. I like Mobil 1 because of the high moly content and ready availability.

I don't believe the Castrol MTX line is available in the US. It is not shown on their US website and the Castrol web page for it shows a bunch of European flags but no US flag.

A W140 seems very thick....am I right inthinking SAE90 gear lube is roughly equivelent to W40 engine lube?

I am sure its good for slightly worn transmissions too....and less likely to leak,

92KK

A W140 seems very thick....am I right inthinking SAE90 gear lube is roughly equivelent to W40 engine lube?

I am sure its good for slightly worn transmissions too....and less likely to leak,

92KK

SAE 90 is what the local BMW dealer said to put in to me. Helpfully they also said to use Halfords own brand stuff as well...

With gear lubricants it is almost impossible to tell what the viscosity is from the ratings on the bottle, a bit like fork oils where if you find a site where they have actually put the oils into a kinematic viscometer the first thing one notes is they tend to have widely differing viscosities at the same temperature. As an ex lubricant chemist for Castrol many many years ago I would pick a premium brand synthetic oil like Mobil 1 or similar with a span of viscosity rating that is above and below (like 70-140) the recommended SAE 90 and use that.

Without going into reams of typing we all need an oil that will circulate around all of the bearing parts to prevent metal to metal contact as quickly as possible when they first start to turn but will retain enough film strength and resist fling off under extreme pressure when hot.

For our gearbox and final drive I have noted that the magnetic drain plugs provided by BMW are PATHETICALLY WEAK and yes I am shouting. Even brand new ones are very very low magnetic strength. I had some discussion with the legendary Tom Cutter the Guru of gearbox and transmission restoration and he said he suspected that they intentionally chose weak magnets so they would not gather too much fuzz on them and frighten the owners. My personal belief is the stronger the magnet the better with the proviso that the Curie point must be high enough to prevent them ever demagnetising at the highest temperature the oil will ever reach. Dimple motor oil magnets in the USA make some quite strong gearbox and final drive magnets for our bikes and they will do a good job of collecting the swarf and taking it out of circulation. I recall when I first read Volvo's bulletin about putting a magnet in the power steering reservoir I did that and what a shocker when I pulled it out a week later. Once it had cleaned it up there is just a faint film at every check.
Regards,
K-BIKE

All of the BMW motorbike-specific gear and engine oils in the US which you can buy from your local BMW dealership are contracted out Spectro brand and have been since the '80s. They are not BMW factory-recommended Castrol with the exception of the SAF-XO synthetic gear oil for the "newer" R/K series hollow final drive and bikes with separate gearboxes from the engine/clutch.

BTW, I am currently using the SAF-XO 80W90 in my R1150RT's gearbox and final drive with great success recently on my 17,700 kms round the US ride. The shifting effort has been reduced and the gearbox seems quieter than when I used the 75W140 gear oil from BMW previously. It costs about the same too. I will carry some home with me to use in my K100RS' gearbox and final drive when I return to OZ next year - too expensive to buy from the Beemer dealers there...

Two Wheels Better wrote: All of the BMW motorbike-specific gear and engine oils in the US which you can buy from your local BMW dealership are contracted out Spectro brand and have been since the '80s. They are not BMW factory-recommended Castrol with the exception of the SAF-XO synthetic gear oil for the "newer" R/K series hollow final drive and bikes with separate gearboxes from the engine/clutch.

BTW, I am currently using the SAF-XO 80W90 in my R1150RT's gearbox and final drive with great success recently on my 17,700 kms round the US ride. The shifting effort has been reduced and the gearbox seems quieter than when I used the 75W140 gear oil from BMW previously. It costs about the same too. I will carry some home with me to use in my K100RS' gearbox and final drive when I return to OZ next year - too expensive to buy from the Beemer dealers there...

Castrol in the US is owned by BP. We do not have the gear oils you mention available for sale in the US.

The gear lube I took out of the bike was a deep red color and I am pretty sure it was the BMW branded 75W140. What I found interesting is even though it was a warm day, it poured out extremely slowly. I use 75W140 Mobil 1 synthetic and it is not so viscous. I was wondering if anyone knew the properties of the BMW branded gear lube, how it differs from other synthetic gear oils?

92KK K100LT 193214 wrote: A W140 seems very thick....am I right inthinking SAE90 gear lube is roughly equivelent to W40 engine lube?

I am sure its good for slightly worn transmissions too....and less likely to leak,

92KK

It is a multi grade, with the viscosity of a 75 weight oil when cold and the viscosity of a 140 weight oil when hot. What this really means is that while a 75 weight straight grade oil is viscous when cold but thins out too much when hot, a multi grade does not loose viscosity as it gets hot. At operating temperature is has the viscosity of a fully hot true 140 weight oil but when cold it pours and lubricates like a cold 75 weight oil. Does that sort of make sense?

Where I live an hour from Death Valley, 140 weight oil is not too heavy, especially in the summer, and the cold weight is appropriate for our below freezing winter mornings.

Themason wrote:Castrol in the US is owned by BP. We do not have the gear oils you mention available for sale in the US.

The gear lube I took out of the bike was a deep red color and I am pretty sure it was the BMW branded 75W140. What I found interesting is even though it was a warm day, it poured out extremely slowly. I use 75W140 Mobil 1 synthetic and it is not so viscous. I was wondering if anyone knew the properties of the BMW branded gear lube, how it differs from other synthetic gear oils?

To all US BMW motorbike dealers the SAF-XO is available in a 200ml container as well as a larger quart container for gearbox-change, part number 33 11 7 695 240. It's 75W90 and is fully synthetic, and it's made by Castrol. I'd give you the part number for the 200 ml bottle but am not at work again until Tuesday.

The others (engine and gear oils) are all sourced by BMWNA exclusively from Spectro, including the red-coloured 75W140, and are packaged in a BMW branded bottle with BMW-type, but US-only, part number. Until a few years ago, the 75W140 was not red but a more traditional honey colour, and also Spectro. Not recommended on your toast, however.

https://media.photobucket.com/image/recent/kurt1305/file.jpg
In this link, note the label info states Spectro as the Manufacturer for BMWNA. This is an engine oil label but the gear oils say the same thing.

I have used the Spectro/BMWNA 75W140 gear oil with great success in my Airhead gearboxes for yonks.

Two Wheels Better wrote:

Themason wrote: Castrol in the US is owned by BP. We do not have the gear oils you mention available for sale in the US.

The gear lube I took out of the bike was a deep red color and I am pretty sure it was the BMW branded 75W140. What I found interesting is even though it was a warm day, it poured out extremely slowly. I use 75W140 Mobil 1 synthetic and it is not so viscous. I was wondering if anyone knew the properties of the BMW branded gear lube, how it differs from other synthetic gear oils?

To all US BMW motorbike dealers the SAF-XO is available in a 200ml container as well as a larger quart container for gearbox-change, part number 33 11 7 695 240. It's 75W90 and is fully synthetic, and it's made by Castrol. I'd give you the part number for the 200 ml bottle but am not at work again until Tuesday.

The others (engine and gear oils) are all sourced by BMWNA exclusively from Spectro, including the red-coloured 75W140, and are packaged in a BMW branded bottle with BMW-type, but US-only, part number. Until a few years ago, the 75W140 was not red but a more traditional honey colour, and also Spectro. Not recommended on your toast, however.

https://media.photobucket.com/image/recent/kurt1305/file.jpg
In this link, note the label info states Spectro as the Manufacturer for BMWNA. This is an engine oil label but the gear oils say the same thing.

I have used the Spectro/BMWNA 75W140 gear oil with great success in my Airhead gearboxes for yonks.

Hmmm, I see late model 16V wheels and Monolever on the rear. Since it is a right side view I am left wondering if a left side view would reveal an 8 valve or 16 valve head and exhaust system. I guess you could have a K1100LT back there with a Monolever rear end. I have even seen a 4 1/2 inch wide K1100RS rear wheel with Monolever but you had to use the 16V exhaust and even then you only had a few mm clearance between the exhaust and the tire. Looks like a 16V fork too.

Anyway, back on topic, I have seen Spectro barrels in the back of a BMW shop so I was aware they supplied the engine oil. I was not aware of the gear lube also being a Spectro product since the last time I used a Spectro brand gear lube, in a gearbox and not on my toast, it was honey colored as you say. Thanks for the information.

Now about that bike of yours ....................

Themason wrote:Hmmm, I see late model 16V wheels and Monolever on the rear. Since it is a right side view I am left wondering if a left side view would reveal an 8 valve or 16 valve head and exhaust system. I guess you could have a K1100LT back there with a Monolever rear end. I have even seen a 4 1/2 inch wide K1100RS rear wheel with Monolever but you had to use the 16V exhaust and even then you only had a few mm clearance between the exhaust and the tire. Looks like a 16V fork too.
Anyway, back on topic, I have seen Spectro barrels in the back of a BMW shop so I was aware they supplied the engine oil. I was not aware of the gear lube also being a Spectro product since the last time I used a Spectro brand gear lube, in a gearbox and not on my toast, it was honey colored as you say. Thanks for the information.
Now about that bike of yours ....................

I pretty well spell it out in my signature line what I've done to the 8V K100RS over the past few years. It currently rides on K75 'S' forks, a 4.5x18" rear wheel, a 2.5x18" front, with a 17" wheel/tyre combo, 305mm discs and a Marzocchi fork all obtained for when I return to OZ next year. The exhaust is a round can Motad from the UK and is a relatively tight fit back there. Some of us who have done that particular wheel/tyre mod in OZ call them the 'Phat Tyred Ladies'.

Yep, the only Castrol oil in the US from the BMW factory is the Castrol-branded SAF-XO 75W90 full synthetic for the later model's 'hollow' final drive and/or gearbox if required. All others are provided by Spectro, engine and gear oils alike. Have a squiz at what ol' Ted says on his BMW site and then look at his 'Addendum' and then 'Further Addendum' at the bottom. This is but one example of confirmation. Tomorrow at work I will jot down all of the part numbers/viscosity/grades and post them up so this forum's members in the US know what they're buying IF they purchase oils from their local dealer.

http://www.beemershop.com/tech00.php

[quote="Two Wheels Better"][quote="Themason"]Hmmm, I see late model 16V wheels and Monolever on the rear. Since it is a right side view I am left wondering if a left side view would reveal an 8 valve or 16 valve head and exhaust system. I guess you could have a K1100LT back there with a Monolever rear end. I have even seen a 4 1/2 inch wide K1100RS rear wheel with Monolever but you had to use the 16V exhaust and even then you only had a few mm clearance between the exhaust and the tire. Looks like a 16V fork too.
Anyway, back on topic, I have seen Spectro barrels in the back of a BMW shop so I was aware they supplied the engine oil. I was not aware of the gear lube also being a Spectro product since the last time I used a Spectro brand gear lube, in a gearbox and not on my toast, it was honey colored as you say. Thanks for the information.
Now about that bike of yours ....................[/quote]

I pretty well spell it out in my signature line what I've done to the 8V K100RS over the past few years. It currently rides on K75 'S' forks, a 4.5x18" rear wheel, a 2.5x18" front, with a 17" wheel/tyre combo, 305mm discs and a Marzocchi fork all obtained for when I return to OZ next year. The exhaust is a round can Motad from the UK and is a relatively tight fit back there. Some of us who have done that particular wheel/tyre mod in OZ call them the 'Phat Tyred Ladies'.

Yep, the only Castrol oil in the US from the BMW factory is the Castrol-branded SAF-XO 75W90 full synthetic for the later model's 'hollow' final drive and/or gearbox if required. [i]All[/i] others are provided by Spectro, engine and gear oils alike. Have a squiz at what ol' Ted says on his BMW site and then look at his 'Addendum' and then 'Further Addendum' at the bottom. This is but one example of confirmation. Tomorrow at work I will jot down all of the part numbers/viscosity/grades and post them up so this forum's members in the US know what they're buying [i]IF[/i] they purchase oils from their local dealer.

[url=http://www.beemershop.com/tech00.php[/quote]http://www.beemershop.com/tech00.php[/quote[/url]]

Interesting. Thanks for the description. I will pass along to you a tip from a friend here in the US who built and tested the prototypes of the K100 and K75. Don't use the Marzocchi fork. It is not durable, it weighs more than the original Fichtel Sachs fork, and has the damping split between the legs. If you really want to go whole hog on a fork, buy an original fork, not the S fork, but the standard Fichtel Sachs fork and use sliders with the built in fork brace like the S fork has, have the inside diameter of each slider nitride coated and use brand new fork tubes and teflon seals at the bottom of each damper rod. You will never wear this fork out, and because there is full contact the entire length of the fork instead of just at a bushing at the bottom that will wear, it ends up being a lighter and more responsive fork. Splitting the damping as is done on both the Marzocchi fork and the later S fork you have is not ideal either. Better to take the old fork and install Race Tech Cartridge Emulators in both legs. This is the hot set up.

Also, unless you change the triple clamps to reduce the offset, changing to a 17 inch front wheel will reduce the already insufficient trail to the point of being dangerous. The primary reason these bikes have a high speed weave, especially when loaded, is a lack of trail. Using a smaller diameter front wheel only makes the problem worse. The triple clamp used with the 16V bikes (K-1, K100RS/16V and K1100) likewise has insufficient trail. You need to use some other triple clamp modified to fit. I have an R100GS triple clamp on one of my Ks. It is a machinests nightmare to make this work, boring the holes, spacing the lower triple clamp,steering stops, fitting guages, etc. An R100R triple clamp is equally ugly to make work. You can also use the triple clamps, even the complete front end, off an original GSX/R-1000 (they used the same steering head bearings) with a modified stem. Don't ask me how it's modded, but I have ridden a K100RS with the Gixxer front end. That works very nicely.

But putting a 17 inch front wheel on the set up you have now is asking for trouble. I know. Even with the 18 inch front tire, there is so little trail that if you load it down for touring and then compress the front end further with a high speed cornering load, such as a certain 130 mph Autobahn sweeper entering Bonn returning from the Dutch GP, you can initiate a weave that has both ends of the bike cycling through the full travel of the suspension while the bars move lock to lock. At 130 mph that is [i]very[/i] scary. Now, with enough trail, the bike never weaves, ever, no matter how much I stuff in the bags or how fast I ride it. It is a little heavier steering, but not much, and the added stability lets you get away with things you would never try otherwise.

Themason wrote:But putting a 17 inch front wheel on the set up you have now is asking for trouble. I know.

But it won't be when I add the Paralever, and requisite gearbox with attachment point for the torque arm, for that added 50mm of wheelbase, just as any K1100RS has. The K75 'S' forks have worked far better for me on the K100RS than the original longer travel and softer setup, even with different springs and fork oil weights, which I've played round with over the years. This bike, as it is now, corners with grace and stability befitting a much shorter wheelbased bike.

One must experiment with different setups to find what suits. Besides, what kid did you ever know who listened to advice, however well-intentioned, without going out and doing just what he or she's told not to? It's inexorable, a rite of passage, our experimentation with different bits, that never stops. No, you must go out and try it for yourveryownbadself. If it works like crap, there's all the original pieces and parts to put back into place, no harm done. Unless of course you're too lame to recognise or admit to a mistake.

BTW, you don't have to add the whole load of previous quotes to your reply post as it only adds to the confusion of who said what and the point gets lost.

Two Wheels Better, adding that 50 mm to the wheelbase doesn't buy you any additional trail. Trail is what stabilizes the steering. If you go with a 17 inch front wheel on the stock triple clamps, you will have stability problems. Take it from people who have tried this. I'm trying to save you some road pizza and broken bones.

What does work and work well is to reduce the offset to increase trail as mentioned, then slide the fork tubes up in the clamps 25 mm and extend the length of the shock. This is how my bike is set up. With the triple clamps I mentioned you have so much more trail, roughly 10-12 mm more, that even with the nose lowered and the tail up, you still have more trail than you started with, less rake and much nicer turn in.

Adding a 17 inch wheel to the set up you have is asking for a high speed weave you won't ever forget. Even with the stock 18 inch front wheel you do not have sufficient trail. Add trail, however, and the bike is extremely forgiving, which is what you want on public roads.