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'04 R1150RT Transmission Oil Recommendation

P

pgm944

New member
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
 
Peter -

Welcome to the forum! I don't think that 75w140 is the right way to go. It certainly isn't on the Airheads, which were produced alongside the Oilhead in the 1990s. I don't own an Oilhead, but I'd go with the manual which probably says GL5 75w90 or 80w90. Here's an older thread which has some discussion:

https://forums.bmwmoa.org/showthread.php?70290-My-R1150RT-Maintenance-Schedule

There are a few other threads in the Similar Threads pane at the bottom of the screen.
 
Quoting myself from 2013:


Finally, and most importantly - gear oil. The basic spec for both the transmission and final drive is 90wt GL5 rated gear oil.

For transmissions only: 80w90 and 75w140 are specified as acceptable.

For final drives: 80w90 is specified as acceptable.

I have found these specifications in the factory manuals for at least 20 different year/model Oilheads and K bikes and have found no other believable specifications for such bikes. One CD, for one year K1200LT differed but was changed backt the following year.

I find it ironic than a person who is using an out-of-spec lubricant in the final drive had a ball bearing failure at 39,000 miles. A review of technical literature regarding ball bearings makes it pretty clear that oil viscosity, operating temperature, bearing clearances, and loading are critical to proper bearing function and to bearing life. Oil that is either too thin or too thick is detrimental.

Specifically, oil that is too thick may, under certain conditions, "wedge" out in front of the rolling balls. This leads to inadequate oil between the balls and the races. This allows the balls and races to go "metal to metal" which is not supposed to happen. This causes fractures and pitting in the hard races and sure impending death for the bearing. This by the way is the failure mode for the vast majority of reported final drive failures.

For all final drives prior to the introduction of the "big hole" drives on the K bikes and R1200, if anybody including a dealer puts 75w140 in a final drive they are not in accordance with the specifications no matter what they say, or how earnestly they say it. And in my carefully considered opinion it does matter and is detrimental to the final drive.

While there are undoubtedly several factors involved in the many final drive failures, improper lubricant is clearly one of them. Others include shimmed to tight (inadequate bearing clearances for the oil), shimmed too loose (pounding), impact loads from sharp bumps (GS bikes anyone?), and excess loading (two-up K1200LT with full camping/touring gear). I would note that proper gear oil providing optimal cushioning can mitigate some, but not all, of the hazards imposed by the other factors.
 
Gear oil

PGlaves said:
Quoting myself from 2013:


Finally, and most importantly - gear oil. The basic spec for both the transmission and final drive is 90wt GL5 rated gear oil.

For transmissions only: 80w90 and 75w140 are specified as acceptable.

For final drives: 80w90 is specified as acceptable.

I have found these specifications in the factory manuals for at least 20 different year/model Oilheads and K bikes and have found no other believable specifications for such bikes. One CD, for one year K1200LT differed but was changed backt the following year.

I find it ironic than a person who is using an out-of-spec lubricant in the final drive had a ball bearing failure at 39,000 miles. A review of technical literature regarding ball bearings makes it pretty clear that oil viscosity, operating temperature, bearing clearances, and loading are critical to proper bearing function and to bearing life. Oil that is either too thin or too thick is detrimental.

Specifically, oil that is too thick may, under certain conditions, "wedge" out in front of the rolling balls. This leads to inadequate oil between the balls and the races. This allows the balls and races to go "metal to metal" which is not supposed to happen. This causes fractures and pitting in the hard races and sure impending death for the bearing. This by the way is the failure mode for the vast majority of reported final drive failures.

For all final drives prior to the introduction of the "big hole" drives on the K bikes and R1200, if anybody including a dealer puts 75w140 in a final drive they are not in accordance with the specifications no matter what they say, or how earnestly they say it. And in my carefully considered opinion it does matter and is detrimental to the final drive.

While there are undoubtedly several factors involved in the many final drive failures, improper lubricant is clearly one of them. Others include shimmed to tight (inadequate bearing clearances for the oil), shimmed too loose (pounding), impact loads from sharp bumps (GS bikes anyone?), and excess loading (two-up K1200LT with full camping/touring gear). I would note that proper gear oil providing optimal cushioning can mitigate some, but not all, of the hazards imposed by the other factors.
Click to expand...

I can only concur with Paul. My 2004 RT with 106k has had regular tranny and rear end oil changes every 12k miles. Only standard GL5 spec 90w has been used in the rear end with zero issues so far.
 
My original 00' GS1150 transmission has 220,000 miles on it and the internals are original except for the input shaft.
It has seen yearly oil changes with 75w90.
No additives, no nothin'. :deal

The only reason why I pulled it out is because I built a GSA transmission with a tall 6th.
 
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