Final Drive Viscosity?

When they changed the recommended viscosity for the final drive did they also change the recommended viscosity of the transmission to 75W90 from 75W140?

SBWayne said:

When they changed the recommended viscosity for the final drive did they also change the recommended viscosity of the transmission to 75W90 from 75W140?

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There was no mention of the transmission oil. The official BMWAG spec is SAE 90 APL GL 5.
BMWNA sells 80W90 dino, 75W90 synth and 75W140 synth under a new part number from the old 75W140. I don't know if it is a different product than the old part number.
I read once that thinner oil is a better coolant. That could be a good thing to consider if it is true.

Data point: when I had the leaky outer seal on my '05 GS final drive repaired under warranty, the dealer (Max BMW in NH - whom I consider a very reputable, by-the-book sort of dealer) put in 75W-140. That was on Sept 6, 2007.

The reason I was asking about 75W140 is because that is what Irv Seaver, the BMW dealer in Orange County sold me for the final drive and transmission a few months ago. So now I am wondering whether I should use it for the transmission, the FD or both or neither.

SBWayne said:

The reason I was asking about 75W140 is because that is what Irv Seaver, the BMW dealer in Orange County sold me for the final drive and transmission a few months ago. So now I am wondering whether I should use it for the transmission, the FD or both or neither.

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I guess I would use what BMW says for the new FD. As far as the trans, I don't think I ever heard or experienced any issues with too heavy an oil issue...or many trans issues in general. There is a circulatory system in a BMW trans...at least there used to be, where the oil is pumped thru the shafts by the gears running. That would make me want to run the thinner, but adequate weight at least in the winter time. But I never had any issues with the K100RSes running 75W140 for at least 60K each or more.

I am totally confused!!! HELP!!!

Oddly, my BMW dealer doesn't stock BMW 75W90 gear oil or Castrol SAF-XO. They do stock BMW 75W140 synthetic gear oil.

I asked my BMW parts guy what they use in their service department for final drive oil in a R1200RT, and he answered, "Regular gear oil -- something in a 55-gallon drum".

If the BMW REP-ROM specifies Castrol SAF-XO, yet BMW NA markets both BMW 75W90 Super Synthetic gear oil and BMW 75W140 Super Synthetic gear oil -- what are we supposed to use?

And, what is so wrong with using BMW 75W140 super synthetic gear oil in the final drive -- why does it even exist?

If BMW 75W140 synthetic gear oil should NOT be used in the final drive, where should it be used? Apparently not the gear box, as the BMW REP-ROM indicates, Brand name hypoid-gear lubricant SAE 90 API GL 5.

What the heck is BMW 75W140 synthetic gear oil for, if not the final drive?

The back-label of "Synthetic BMW Gear Oil SAE 75W140 Super Synthetic" reads exactly as follows:

Super Synthetic Engine Oil / SAE 75W140
ÔÇó Recommended for all BMW motorcycles after 1970
ÔÇó Field Tested by BMW NA.
ÔÇó High-performance synthetic provides high load-carrying characteristics, minimum foaming, and exceptional resistance to thermal degradation and oil consumption.
ÔÇó Exclusive chemistry reduces internal friction and enhances power output under extreme conditions
BMW SAE 75W140
Synthetic Gear Oil

Sold by BMW of North America, LLC, Woodriff Lake, NJ 07675. Formulated, Blended and packaged exclusively for BMW of North America by Spectro Oils of America.

Is BMW Gear Oil SAE 75W140 Super Synthetic an acceptable alternative gear oil to BMW Gear Oil SAE 75W90 Super Synthetic in certain applications?

gulfcoastbeemer said:

...I asked my BMW parts guy what they use in their service department for final drive oil in a R1200RT, and he answered, "Regular gear oil -- something in a 55-gallon drum".

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BMW recommends synthetic oil in the FD. What the parts guy told you is incorrect. Either he is mistaken (he's a parts guy commenting on practices in the service dep't) or, if he's right, the dealership is not following BMW recommendations. You might try asking the service department...

... The back-label of "Synthetic BMW Gear Oil SAE 75W140 Super Synthetic" reads exactly as follows:

Super Synthetic Engine Oil / SAE 75W140
ÔÇó Recommended for all BMW motorcycles after 1970
ÔÇó Field Tested by BMW NA.
ÔÇó High-performance synthetic provides high load-carrying characteristics, minimum foaming, and exceptional resistance to thermal degradation and oil consumption.
ÔÇó Exclusive chemistry reduces internal friction and enhances power output under extreme conditions
BMW SAE 75W140
Synthetic Gear Oil

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Does it REALLY say "engine" ???

... Is BMW Gear Oil SAE 75W140 Super Synthetic an acceptable alternative gear oil to BMW Gear Oil SAE 75W90 Super Synthetic in certain applications?

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What part of "recommended for all BMW motorcycles after 1970" isn't clear enough?

As I commented in an earlier post, I have BMW 75W140 in my FD right now. It was put there by Max BMW, a very reputable dealer, about a month ago.

Multi-viscosity gear oil designations work like motor oil - the first number is the viscosity when cold, so 75W140 has the same viscosity as a straight 75 gear oil when cold. That is relatively thin, and I suspect it helps with flow at cold temperatures. The other number is the viscosity when hot, so 75W140 has the same viscosity when hot as a straight 140 oil when hot. That's pretty thick, and here, I suspect it helps in the following manner: oil is distributed around the FD by sticking to the gear teeth and being carried around. Too thin, and it gets flung off, and may not reach the places it needs to reach.

gulfcoastbeemer said:

I am totally confused!!! HELP!!!

Oddly, my BMW dealer doesn't stock BMW 75W90 gear oil or Castrol SAF-XO. They do stock BMW 75W140 synthetic gear oil.

I asked my BMW parts guy what they use in their service department for final drive oil in a R1200RT, and he answered, "Regular gear oil -- something in a 55-gallon drum".

If the BMW REP-ROM specifies Castrol SAF-XO, yet BMW NA markets both BMW 75W90 Super Synthetic gear oil and BMW 75W140 Super Synthetic gear oil -- what are we supposed to use?

And, what is so wrong with using BMW 75W140 super synthetic gear oil in the final drive -- why does it even exist?

If BMW 75W140 synthetic gear oil should NOT be used in the final drive, where should it be used? Apparently not the gear box, as the BMW REP-ROM indicates, Brand name hypoid-gear lubricant SAE 90 API GL 5.

What the heck is BMW 75W140 synthetic gear oil for, if not the final drive?

The back-label of "Synthetic BMW Gear Oil SAE 75W140 Super Synthetic" reads exactly as follows:

Super Synthetic Engine Oil / SAE 75W140
ÔÇó Recommended for all BMW motorcycles after 1970
ÔÇó Field Tested by BMW NA.
ÔÇó High-performance synthetic provides high load-carrying characteristics, minimum foaming, and exceptional resistance to thermal degradation and oil consumption.
ÔÇó Exclusive chemistry reduces internal friction and enhances power output under extreme conditions
BMW SAE 75W140
Synthetic Gear Oil

Sold by BMW of North America, LLC, Woodriff Lake, NJ 07675. Formulated, Blended and packaged exclusively for BMW of North America by Spectro Oils of America.

Is BMW Gear Oil SAE 75W140 Super Synthetic an acceptable alternative gear oil to BMW Gear Oil SAE 75W90 Super Synthetic in certain applications?

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I would use the 75W90 synth that the BMW bulletin says to use in the new final drives...the K2x and K4x bikes. As far as the trans goes and the fd in the older bikes, AND maybe even the new fd in those new bikes, I guess you could use the 140, but it is probably not necessary.

cjack said:

I would use the 75W90 synth that the BMW bulletin says to use in the new final drives...the K2x and K4x bikes. As far as the trans goes and the fd in the older bikes, AND maybe even the new fd in those new bikes, I guess you could use the 140, but it is probably not necessary.

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I would NOT use 75w140 in any BMW final drive. BMW specs allow it in transmissions but 90 wt or 80w90 wt or 75w90 wt is spec'd for final drives in every maintenance manual I have found.

soffiler said:

Does it REALLY say "engine" ???



What part of "recommended for all BMW motorcycles after 1970" isn't clear enough?

As I commented in an earlier post, I have BMW 75W140 in my FD right now. It was put there by Max BMW, a very reputable dealer, about a month ago.

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Thanks for the reply.

YES, it does say engine in that one place on the back-side label; however, it is clearly marked gear oil everywhere else.

I can take a picture of the front and back of the BMW product if there is any serious doubt about that. I should have made a comment about the word engine in the original post. All, I can figure is it's a result of pretty careless proof-reading on the part of BMW NA. Figures.

It appears we have two groups of people -- equally confident, and equally divided as to whether it's BMW 75W90 or 75W140 Super Synthetic Gear Oil that should be used in the final drive.

As far as the "manual" is concerned, I now have about as much confidence in it as the back-side label of the BMW Gear Oil. The $125 BMW REP-ROM specifies Castrol SAF-XO, which is a 75W90 gear oil that does not have fiction modifiers. Good luck finding it anywhere in the United States. And, who knows if that is what is currently recommended in light of much publicized final drive issues.

When I purchased my wife's '05 R1200RT the final drive was sealed for life -- maintenance free. When I purchased my '07 R1200RT the final drive was sealed for life -- maintenance free; but BMW NA issued a tech bulletin shortly after I bought it, and recommended a 600 mile drain and refill. Who knows what the real deal is presently.

I have spoken the BMW NA on other issues and have come the conclusion they are just about worthless. Each time I have asked them a question, they have dodged the issue and have asked me to consult with my dealer. Well, my dealer is a multi-brand dealer with a 55-gallon drum of generic gear oil.

The recommended for BMW motorcycles language on the 75w140 bottle applies to transmissions. It even says so in the repair manuals.

But the repair manuals do not say so for final drives.

It's your bike - use what you wish. I prefer to use the grade and viscosity specified by BMW as stated in the repair manuals and owner's manuals.

PGlaves said:

The recommended for BMW motorcycles language on the 75w140 bottle applies to transmissions. It even says so in the repair manuals.

But the repair manuals do not say so for final drives.

It's your bike - use what you wish. I prefer to use the grade and viscosity specified by BMW as stated in the repair manuals and owner's manuals.

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Have you actually read the the bottle -- that is, Gear Oil BMW 75W140 Super Synthetic?

This bottle does NOT mention transmission or final drive. It labeled GEAR OIL -- without any further clarification.

I don't know whose "repair manual" you are citing; but the BMW REP-ROM repair manual clearly states:

Final Drive: Castrol SAF-XO
Gear Box: Brand Name hypoid-gear lubricant SAE 90 API GL 5

As you can see the, BMW Repair Manual (REP-ROM) does NOT recommend BMW Gear Oil 75W140 in either application. So this seems to beg the question: is BMW NA marketing an oil that has no known application, or is there is some BMW service bulletin or BMW publication that clarifies where this GEAR OIL should be used.

The BMW Rider's Manual (US Model) R1200RT 3rd Edition: Rear-wheel drive design; Shaft drive with bevel gears (no mention of lubricant type).

Please share with us what BMW publication you are citing, and quote it.

Yes - I have read the gear oil bottles for all three types of BMW branded gear oil.

The 75w140 synthetic says it is suitable for all post 1970 BMW motorcycles - without reference to transmissions or final drives.

The 80w90 says that it is suitable for use in transmissions AND final drives for 1970 and later BMW motorcycles.

The 75w90 synthetic also specifically references both transmissions AND final drives on post 1970 motorcycles.

I do happen to think that the language that is used on the 75w140 bottle is misleading. I am sure the differences in the language on the 80w90 and 75w90 bottles making reference specifically to transmissions and final drives was no accident. I also suspect that the vague language on the 75w140 where "motorcycles" were mentioned but final drives were not mentioned was also no accident.

In any event - the repair manuals and little owner's manuals for each model published by BMW do specify the correct lubricant to use in the transmission and final drive; to wit for the old style Oilhead and K bike drives:

Transmission: 90 wt GL5 gear oil if over 42 degrees F; 80 wt GL5 gear oil if under 42 degrees F; 80w90 wt GL5 gear oil OR 75W140 GL5 gear oil are acceptable substitutes.

Final Drive: 90 wt GL5 gear oil if over 42 degrees F; 80 wt GL5 gear oil if under 42 degrees F; 80w90 wt GL5 gear is an acceptable substitute.

I have previously stated publicly and written in the Owners News (July, 2007) that it is my carefully considered personal opinion that the use of improper viscosity gear oil which is thicker than specification is a contributing factor in the rather sudden increase in final drive failures which occurred time coincident with the introduction of the BMW branded 75w140 gear oil on the dealership shelves, and its widespread out-of-spec use by dealers and owners.

I have been chided and yelled at by a few dealers for that position but not one has yet been able to provide me documentation or a reference to documentation from BMW that says that anything heavier than 80w90 is acceptable in final drives. A couple of people did write that the "bottle says its OK", but given the specific language about final drives on the 80w90 and 75w90 bottles I don't believe the vague reference to "motorcycles" on the 75w140 bottle trumps the language in repair manuals or owner's manuals.

As for which documents: for the new sealed drives, the document is the bulletin issued by BMW pertaining to the oil change at the 600 miles service. it says 75w90. The 75w90 oil is also shown on the repair parts listing.

As for the older style final drives, what I wrote above is what it says in my R1100RS, R1150R, R1100S, K1100LT, and K75 owners manuals and my R1100RS/GS Repair Manual and my R1150RT and R1100S Repair Manual CDs.

But - as I wrote earlier - its your bike. Use what you want. I prefer to use gear oil which meets the viscosity specifications published by BMW.

One more thought on the topic.

Since several dealers have only been able to show me specifications for final drive lubricant of 90 wt, 80 wt, 80w90 wt, or 75w90 wt. gear oil - maybe the owners on this forum can find additional specifications for one or more specific models. I've looked at over a dozen repair manuals but haven't looked at them all.

So: if you have a little book (Owner's or Rider's Manual) or a Repair Manual published by BMW for a post 1970 BMW motorcycle that specifies a FINAL DRIVE GEAR OIL THICKER THAN 90 WT please post that information here.

I don't think we need every reference to "yes - it says 90 wt" but certainly if it says anything heavier than 90 wt it would be instructive.

Please be specific - model, year, which manual, date of manual, etc.

Thanks

I just had a telephone conversation with BMW North America Customer Relations in Woodcliff Lake, NJ regarding what gear oil was to be used in my wife's '05 R1200RT and my '07 R1200RT. The BMW NA representative was very attentive to my concern and seemed very knowledgeable on the issue of final drive lubricant.

He referenced internal discussions that BMW Customer Relations had recently had with technical representatives within BMW regarding this very issue. This was not his first call on this issue. This Customer Relations representative felt he was up to speed on the issue and was familiar with all currently available information regarding final drive lubricant.

The BMW NA Customer Relations representative clearly stated that either BMW Gear Oil product -- 75W90 or 75W140 Super Synthetic was recommended in my final drive. He did state that ultimately individual BMW dealers might have a preference based on other considerations as to which might be used-- he didn't elaborate, perhaps climate or season of the year, who knows. But, in any event, he was very clear that BMW had formulated 75W140 Super Synthetic for use in the final drive of my particular model/year BMW motorcycles, and under no circumstance was it harmful to the final drive of these vehicles.

If anyone else want to have a go at it, the telephone number for BMW NA is 1-800-831-1117.

I'm glad BMW tech reps and service reps now have the Hexhead and New K bike drive lube figured out.

They originally said there was a lifetime fill from the factory. Then they said change it at 600 miles. When I asked what to fill it with at 600 miles they said 75w140 synthetic. That's what I wrote in my July article. Then they issued the bulletin which said 75w90 and showed 75w90 on the parts fiche.

Now they say verbally either is acceptable. I'll accept that. I feel better because that means my article in July wasn't wrong.

Since the bulletin says 75w90 and that's what they show on the fiche, I would personally still use the 75w90 but Customer Service says either is OK, so that's OK by me.

I still would like to see any BMW documentation (if it exists) as to heavier than 90 wt oil in the Oilhead and old K bike final drives.

If any body has such in an owner's or repair manual that specs heavier than 90 wt. please let me know.

FWIW, when my independent BMW Master tech changed the FD oil in my '06 R12RT in November 2006, he used "SAF-XO Synth F/D Oil". I know it was Castrol from looking at the bottle (after he told me the price, I wanted to check it out). He said that that's what BMW specified.

In July 2007, my final drive failed on a long trip and was replaced (under warranty) in Salt Lake City. A week later, I had the FD oil changed in my new final drive at Brown Motor Works, the BMW dealer in Pomona, California. They used "Super Synth 75/90", P/N 07510394082.

PGlaves said:

So: if you have a little book (Owner's or Rider's Manual) or a Repair Manual published by BMW for a post 1970 BMW motorcycle that specifies a FINAL DRIVE GEAR OIL THICKER THAN 90 WT please post that information here.

Please be specific - model, year, which manual, date of manual, etc.

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Well, this isn't precisely what Paul is asking, but since this is the Hexhead forum, it seems pertinent to list what the hexhead's Rider's Manual says about the final drive lubricant:

nothing. zero, zip, zilch, the bubble.

More specifically, under "Fuels and Lubricants" on pp. 167-168, the only mention of gear oil is with respect to the transmission, and it calls for Castrol SAF-XO. No surprise there. Nor is there any surprise that they ignore the final drive lubricant, since back then everyone was still under the impression that it was a lifetime lubricant from the factory.

The Haynes Manual "BMW R1200 Twins '04-'06" (copyright Haynes Publishing 2007) likewise ignores the final drive lubricant. For the transmission it calls out "API grade GL-5 SAE 90"

This is an '05 R1200GS built 12/04; can't find any date on the Rider's Manual.

2007 owners manual

PGlaves said:

One more thought on the topic.


So: if you have a little book (Owner's or Rider's Manual) or a Repair Manual published by BMW for a post 1970 BMW motorcycle that specifies a FINAL DRIVE GEAR OIL THICKER THAN 90 WT please post that information here.


Please be specific - model, year, which manual, date of manual, etc.

Thanks

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R1200ST, 2007, purchased 7/07, owners manual, 3rd edition 6/2006.

This little book says absolutely nothing about lubricant specs for either the FD or the tranny, it only mentions engine oil. I was surprised at the omission and double checked, nothing.

Following the most recent BMW bulletin makes as much sense to me as anything else here.

progress49 said:

R1200ST, 2007, purchased 7/07, owners manual, 3rd edition 6/2006.

This little book says absolutely nothing about lubricant specs for either the FD or the tranny, it only mentions engine oil. I was surprised at the omission and double checked, nothing.

Following the most recent BMW bulletin makes as much sense to me as anything else here.

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This kind of issue is the most frustrating. So far the bulletin is the way to go, but it says nothing about the bikes earlier than '07. One report on this forum said that BMWNA's advice on the phone was to change all the new FD bikes fluid no matter what year with the new synth 75W90. Many dealers probably don't know that, whether it is advisable or not. Is this person at BMWNA knowledgeable? Then dealers also make their own policy to use one FD oil or another and periodic changes or not as their experience or lack of it directs. The underlying cause of all this confusion is a total lack of guidance from BMW on the issue and the cause of that is probably worry about opening themselves up to warranty fluid changes and litigation.
Except for Death Valley in the summertime, I think I'll stay with the 75W90 synth.