04 R1150RT Transmission Oil Recommendation

[pgm]

Hi All -  What is the current thinking on what transmission oil to use on my 2004 R1150RT?

I reviewed posts that I could find on all oilheads. 

It seems that Mobile 1 (75w140) might be better than BMW recommendation (90W?). 

I am hesitant to go to RedLine Heavy, but could quiet shifting. 

 

No major issues with transmission, just the normal "hard to engage 1st" at stop lights (release clutch, rev, shift) and clunking between 1-2, sometimes 3rd. 

Bike has 19K miles on it.

 

Oh yes, how often do you guys change it? 

Yearly or by miles?

 

Thanks in advance.

peter

 

[dirtrider]

16 minutes ago, pgm said:

Hi All -  What is the current thinking on what transmission oil to use on my 2004 R1150RT?

I reviewed posts that I could find on all oilheads. 

It seems that Mobile 1 (75w140) might be better than BMW recommendation (90W?). 

I am hesitant to go to RedLine Heavy, but could quiet shifting. 

 

No major issues with transmission, just the normal "hard to engage 1st" at stop lights (release clutch, rev, shift) and clunking between 1-2, sometimes 3rd. 

Bike has 19K miles on it.

 

Oh yes, how often do you guys change it? 

Yearly or by miles?

 

Thanks in advance.

peter

 

 

 

Morning Peter

 

Current thinking is all over the map.

 

Problem is: what works in yours the best might work in mine the worst.

 

I have yet to see an 1150 6 speed bike where Red Line heavy works even close to the best. Now on the older 1100 5 speeds the Red Line heavy can improve the noise/shifting on some (but not all or to say not across the board).

 

Best advice that I can give it to try a different gear oils in your transmission then use the one that shifts the best for the longest time.

 

Some gear oils will give false positives  as right after a change they shift just great, what you don't read about is how the shifting degrades over time but the poster never returns to post that important info.  (most gear oil shears in a gear to gear mesh environment, especially with helical gear sets)

 

I will say  that the Mobil 1 (75w140) is a good starting place as it seems to work OK in most 1150 6 speeds. Might not be the overall best in YOUR transmission but I can just about guarantee that it will work acceptably.

 

So, bottom line--   start with an up-level mainstream gear oil, then get a long mileage base line, then try different gear oils to see if you can find one that works a little better in YOUR transmission.  Just don't jump to a conclusion at 300  miles as just about any new gear oil will be a improvement over what you just drained out. See how it is performing at 3000+ miles. 

 

If you do choose to try the Red Line then do it last as once that stuff gets into your trans it takes many many gear oil changes to completely disappear. 

 

 

[Oldrider51]

My 2 cents. Have an 04 R1100S (second one), and have used only 75W-90 or 80w-90 GL5 gear oil from Belray, Maxima, and Castrol and all have worked well in these bikes. Always get a small clunk into 1st but otherwise shifting is good, but maybe a different transmission design. 

[pgm]

@dirtrider - Agree, without some data, it is all opinion.

@041100S - Agree - it seems, maybe, just maybe, BMW Motorad knows what should work the best, which in my manual includes what you list.

 

I'm sticking with the recommended oils & viscosity. 

[dirtrider]

18 minutes ago, pgm said:

 

I'm sticking with the recommended oils & viscosity. 

 

Afternoon  pgm

 

That is a safe approach, problem is if you stick with one gear oil then you will never know if there is something out there that will shift better (or shift better longer) in your particular transmission.  

 

 

[Claudio]

I switched to Royal Purple 75-90 (its suitable for applications that call for API GL-5 or GL-4.  My transmission is practically silent. 

 

I have noticed, however, the oil doesn't have a tremendous lifespan, possibly due to the extreme climate I ride in, so I change it each season or after a longer trip.

[JamesW]

I like Motul 80-90 with molybdenum for the transmission but stick with any quality dino 80-90 for the final drive.  Buy the Motul on Amazon and I really like the bottle it comes in.  The difference in transmission noise in my '93 R1100RSL is nothing short of remarkable.  However, your 1150 will never make the same noise my early oilhead transmission makes and for my bike the racket is pretty normal.  Also, I would stick with the lubricant weights recommended by BMW especially in the final drive.  Just no need to reinvent that wheel, imo.

[Paul De]

Am I wrong but at one time BMW sold two grades of BMW branded GL-5 rated oil and one was much higher viscosity?   The higher viscosity grade was 75w-140 and was sourced from Spectro(?) but they no longer sell the heavier gear oil.   Anyway that is what I have been running in my R1100 5 speed and rear drive but used up the last of my supply last fall and was going to buy the Spectro labeled stuff for the next round of gear oil change.   It could be a little stiff shifting on a cold morning but once warm it works great in that clunk box of a transmission.  Not sure this info is relevant for a 1150 6 speed though.

[Still CAL]

A quick side q on multi-viscosity fluids. Does an oil with a 75w-140 rating shear quicker than something like a straight 90 weight or an 80w-90? Or does it have to do with dino vs synthetic or just manufacturer quality control?

[pgm]

Multi-viscosity refers to the ability to change viscosity with temperature to insure proper lubrication over a wide operating range.  This is accomplished thru the addition of polymers and is independent of the base oil.

[Paul De]

14 hours ago, pgm said:

Multi-viscosity refers to the ability to change viscosity with temperature to insure proper lubrication over a wide operating range.  This is accomplished thru the addition of polymers and is independent of the base oil.

Agree, but would restate slightly and not say ability to change, but  rather indicates the rate of viscosity change in the oils viscosity over the temperature range of 0F to 212 F.
 

This was copied from Totals website:

Viscosity is notated with the common "XW-XX." The number preceding the "W" rates the oil's flow at 0 degrees Fahrenheit (-17.8 degrees Celsius). The "W" stands for winter, not weight as many people think. The lower the number here, the less it thickens in the cold. So 5W-30 viscosity engine oil thickens less in the cold than a 10W-30, but more than a 0W-30. An engine in a colder climate, where motor oil tends to thicken because of lower temperatures, would benefit from 0W or 5W viscosity. A car in Death Valley would need a higher number to keep the oil from thinning out too much.

The second number after the "W" indicates the oil's viscosity measured at 212 degrees Fahrenheit (100 degrees Celsius). This number represents the oil's resistance to thinning at high temperatures. For example, 10W-30 oil will thin out at higher temperatures faster than 10W-40 will.

 

Shear thinning is a bit different in that the base oil and polymeric additives are broken into smaller molecules and I would expect it to not be directly related to the viscosity change over temperature other than  shear thinned oil would likely have a permanent change in its original viscosity temperature curve. speculating further it may have a negative impact on lubrication if the oil no longer was able to leave a sufficient oil film on the metal parts that are meshing together.

[Still CAL]

Thanks, good stuff.

[dirtrider]

On ‎9‎/‎28‎/‎2019 at 1:31 PM, Still CAL said:

A quick side q on multi-viscosity fluids. Does an oil with a 75w-140 rating shear quicker than something like a straight 90 weight or an 80w-90? Or does it have to do with dino vs synthetic or just manufacturer quality control?

 

Morning Still CAL

 

It can shear quicker but it doesn't necessarily always do that.

 

As mentioned above it has a lot to do with amount of polymers in the gear oil to achieve the   multi-viscosity rating.

 

Some of the very up-level synthetic gear oils get the viscosity spread using high end synthetic  base stock & good oil engineering  (not a lot of polymers added) so those don't tend to shear easily. (they also cost a lot more to produce).

 

Cheaper conventional based gear oils tend to use cheaper to engineer polymers to get the multi-grade viscosity spread so those do tend shear more easily  & shear  quicker. This is also the reason that you seldom if ever see convention gear oil  in a 75w140 rating. Almost all 75w140 gear oil is at least partially synthetic. (some a lot more robust than others)

 

The farther the spread between the low number & the high number the more likely to shear unless the gear oil is a very up-level synthetic with very few polymers added. 

 

Remember that both 75-90 & 75-140 are basically 75 weight gear oils when cold & never EVER get any thicker than their base rating. The difference is that the 75-90 doesn't thin out to  any thinner than a 90 weight would at 100°c & the 75-140 doesn't thin out to any thinner than a 140 weight would at 100°c but both 75w90 & 75w140 do get thinner as they heat up in use (never thicker).  

 

The thing with motorcycles is the gear oil seldom if ever gets any where near  100°c during normal riding.

 

In most motorcycle usage situations an 80 weight or 90 weight will have a higher working viscosity during most riding situations than either a 75w90 or a 75w140 gear oil will. Apples to apples the 80 weight or 90 weigh will usually shear less  but that isn't  a given just a general rule.

 

The thing to keep in mind is that most modern gear oil is sold to & used by the large trucking industry so their usage requirements are the drivers in the performance requirement of most modern vehicle gear oils. In most cases that is gear tooth loading protection & increased fuel mileage with gear noise not  being a priority.

 

When it comes to gear noise that is not as gear oil viscosity related as most think, it is more related to the cling-ability of the gear oil. An 80 weight gear oil that clings like snot to the gear teeth is usually a lot quieter than a high end 75w140 that is designed to increase fuel mileage, decrease gear tooth wear,  & go long term between changes.   The down side to a more clinging type gear oil is that it can hinder smooth shifting  in motorcycle type transmissions (especially when cold).

 

 

 

 

 

[pgm]

@dirtrider  @Still CAL

 

Not to pettifog this discussion,

Multi-Weight ratings (75w150) is about temperature performance 

Shear is about "rpm" or speed of moving surfaces being lubricated and is more aligned with API ratings (ie; SA vs SN).

 

Agree with the rest of DR's post (ie; polymer additive  mostlyfor temp performance vs carbon chain length distribution for shear performance)

Also, other additives, like molybdenum, can change gear friction.

 

 

[dirtrider]

28 minutes ago, pgm said:

@dirtrider  @Still CAL

 

Not to pettifog this discussion,

Multi-Weight ratings (75w150) is about temperature performance 

Shear is about "rpm" or speed of moving surfaces being lubricated and is more aligned with API ratings (ie; SA vs SN).

 

Agree with the rest of DR's post (ie; polymer additive  mostlyfor temp performance vs carbon chain length distribution for shear performance)

Also, other additives, like molybdenum, can change gear friction.

 

 

 

 

Afternoon

 

Shear is about "rpm" or speed of moving surfaces being lubricated and is more aligned with API ratings (ie; SA vs SN).--Where did you get this info from? Shear has nothing to do with API ratings or speed of moving surfaces, it is simply the viscosity breakdown (shearing) of the gear oil viscosity during usage.

 

https://www.synforce.com.au/shear_stability.html

[Still CAL]

Okay, plenty to go on with. It still comes down to DR’s comment, try to find what works best for me and my RT. I think for me the bigger concern is synthetic vs dino and curtailing seeps. I’m done hijacking this thread, I’ll start another one on that topic. 

[pgm]

@dirtrider

Aligned with, not a measurement of... SSI and API designations are marketing terms, not scientific.  API designation of SA is/was for cars around the 1920/30's era & does not have the viscosity performance under shear of a modern oil formulation. API designations of SM or SN have better shear and other performance requirements than SA.  SSI are broad buckets of viscosity-shear performance.  Thus, both are aligned with, but not measurements of performance.  

 

I ran viscosity studies for Exxon and polymer companies in graduate school and in my first job at a corporate R&D center.  While that was late 70's & early '80s, the test methods probably have not changed much, just the data acquisition instrumentation.   Viscosity (M^2/Sec or centipoise) was measured between two moving surfaces across a range of temperatures and shear.  Shear unit of measurement is Load over Area (ie: Lbs/SqFt or Pascals). 

 

On a molecular level, the long carbon chains of the oil starts to align with the shear and has less entanglements (thins).  Think a bowl of spaghetti and pulling on just one...the whole mess comes along.  Align them, like shear forces do, and just the one pulls out.  Viscosity modifiers are like the tomato sauce, allowing the tangled spaghetti to more easily slip past each other when you pull on just one.  This allows longer chains of carbon in the oil molecule or a distribution of chain lengths.   Other modifiers work in reverse...thicken when sheared They typically are branched vs linear polymer chains and is like a rope that knots up on itself when you pull one end. 

 

It's all fascinating to test in the laboratory, but the real world does not always equate. 

Level of shear (either gear loading or moving surfaces) in a transmission is (was?) not easy to calculate.

Getting formulations with a "flat" viscosity curves over a range of shear and temperatures is (was?) an art.

This is where our experience trying different oils is important.

Thus, my original question of what folks find are effective in our clunky transmissions.

 

[dirtrider]

33 minutes ago, pgm said:

 

Thus, my original question of what folks find are effective in our clunky transmissions.

 

 

 

Afternoons  pgm

 

This one is very easy to answer, try a number of gear oil's then keep using the one that works best in YOUR transmission.

 

When it comes to the BMW constant mesh motorcycle transmissions they do not all respond the same to any one  specific gear oil.  (the 5 speed is usually different than the 6 speed in gear oil likes & the early ("O" ring equipped 5 speeds are very picky on gear oil like's).

 

You need to look for best shifting right after a gear oil change (a fairly large number do well here), then look for best shifting & smoothness after about 2000-3000 miles (this  is the definer).

 

From past experience the Mobil 1 (either 75w90 or 75w140) are a good baseline to start with, probably not the best but way above average. Then once you have a baseline try others then compare to your baseline. (again you need to look at the 2000 mile plus data to make a determination).

 

You have to give the gear oil a couple of thousand miles to really tell much when choosing what works best in your specific transmission.

 

If you want quiet then don't overlook the single weight's as a good quality conventional 90 weight GL5 is usually quieter than the thinner 75wXX multi-viscosity selections but the shift quality (especially cold) is usually better  with an unlevel multi-weight synthetics.      

 

(just as an example)-- A few years back I decided to try a Royal Purple 75w140 in my hexhead 6 speed as I had heard good things about how good it worked in other's hexhead bikes.   

 

First ride on that gear oil made me a believer as it was quiet & shifted exceptionally  good, smooth shifts & less clunk. By the time that gear oil got to 1500 miles it was the worst gear oil & had tried to date (it was relatively inexpensive so probably was full of cheap polymers to get the  75 to140 viscosity spread).

 

In any case had I made a recommendation based on just-after-change it would have been excellent, if I made a recommendation based on 1500 miles on that gear oil it would have been to the low side of poor.

 

 

 

 

 

 

 

 

[pgm]

2 hours ago, dirtrider said:

Mobil 1 (either 75w90 or 75w140) are a good baseline to start with,

I use, and happy with, Mobil 1 for engine oil, so it seems like a good starting point for tranny oil.

 

2 hours ago, dirtrider said:

I decided to try a Royal Purple 75w140 in my hexhead 6 speed

I too heard good things.  Are the HexHead tranny that different from my 2004 6 speed?  If not, I might pass...or experiment to verify.

I will stay away from RedLine - just seems too irreversible from what I gather.  

 

Thanks for the practical insights!

[pgm]

3 hours ago, Still CAL said:

I think for me the bigger concern is synthetic vs dino and curtailing seeps.

This might help you decide:

https://www.consumerreports.org/car-maintenance/should-you-use-synthetic-oil-in-your-car/

 

CR tends to be independent and fact based.

[dirtrider]

2 hours ago, pgm said:

I use, and happy with, Mobil 1 for engine oil, so it seems like a good starting point for tranny oil.

 

I too heard good things.  Are the HexHead tranny that different from my 2004 6 speed?  If not, I might pass...or experiment to verify.

I will stay away from RedLine - just seems too irreversible from what I gather.  

 

Thanks for the practical insights!

 

Evening PGM

 

Yes, big difference.

 

Both the 6 speed hexhead trans & the 1150RT use  a dry clutch with constant mesh  transmission gear sets  but that is about all they have in common.

 

The 1150 is predominantly a straight cut gear trans & the 1200 hexhead is a helical gear trans.

 

The 1150RT trans uses a couple of sliding gears that need to actually slide while meshed to engage the shift  (dogs) teeth & complete the drive coupling while the  1200RT hexhead mostly use sliding splined collars between the free spinning gear sets to engage the (dogs) teeth & complete the drive coupling.