another final drive fails

[rado360]

I spoted some metal flakes in my oil so I took it apart and found the big bearing was rough but still together so it was an easy fix,a day later a buddy calls to see if I can replace his rear seal,when I drained the oil pieces of bearing cage were on the magnet.Still no other damage so another easy fix,but boy what is going on with these things.His bearing still had nice shiny balls,mine looked like they were dull grey? We both have 97 RTs mine with 65k and his has 45k
:violin

[Mr. Frank]

Do you know if the rear drives had synthetic or dino gear lube?

[ultracyclist]

I just replaced my final drive support bearing at 36k on an '02 R1150R.

The former owner was a BIG (300lbs +, now weighs about 260) guy, and rode the bike for about 33k miles. I bought the bike used at that milage. But, I am a newbie. I did not know what questions to ask. Besides, my friends and clients were all in love with BMW, so why should I not be in love with BMW?

The final drive support bearing is the weakest link in the power/drive system.

So, I have to ask you...do you do alot of of 2 up riding?.....carry alot of gear?...what do you weigh?

Not to hijack this thread....I just had the 36k service with valve adjustment, and now at 37,980 miles, the $#$%^&**&^ thing is starting to surge again! (yes, I am whining...)

This is my first bike. I love it. I made the committment to keep it for 3or 4 years. I love the BMW culture, and I have met some absolutely terrific people. But I am frustrated with the machinery.

[rado360]

I know only that mine has dino oil and I change at least twice a year for the last 4 yrs.But now I change it with my engine oil so I can inspect it.I will find out what my buudy was using and post it.

And in answer to the wieght, I wiegh 195 and always carry side cases with stuff in them, not much 2 up riding, and by the way this was the first time I changed drive oil and found it looking dirty besides the very small shiny particals

[Motorman]

Are you saying that the oilheads are NOT suitable for consistent 2 up driving??? I'm asking as I am looking for an oil head and we tend to drive 2 up a lot since our bike's our promary sight seeing machine.

[ultracyclist]

motorman-I sent you a pm.

[Mr. Frank]

I know only that mine has dino oil and I change at least twice a year for the last 4 yrs.But now I change it with my engine oil so I can inspect it.I will find out what my buudy was using and post it.



Thanks. The reason I asked is that in a couple of seminars in Vermont Paul Glaves was recommending that people avoid using synthetic gear lube in the rear drive. He said that seemed to be one factor in the high failure rates. He reported that BMW Canada recommends regular gear lube for the rear drive. Obviously, synthetic gear lube was not a factor in your case. The biggest factor seems to be a crappy design.

[jdiaz]

Obviously, synthetic gear lube was not a factor in your case. The biggest factor seems to be a crappy design.
Is it me Frank, or are you using the word "crappy" a lot this week?

Its because the Bunny is so far away, isn't it? :laugh

[Mr. Frank]

Is it me Frank, or are you using the word "crappy" a lot this week?

Its because the Bunny is so far away, isn't it? :laugh

Hi Jon,
I guess twice is a lot. Maybe the guy who designed the MOA rally tee shirt designed the rear drive.

[j-budimlya]

And ride two up with lots of weight...

and at 40k the oil is still clear as can be...

but I do change it often...with every oil change...

[Motorman]

If you change it at every oil change, how much oil is it and what interval do you change your oil at?

[Bokrijder]

I'm posting a portion of a PM which I wrote some time ago. My GS has a new final drive unit which I installed just before the POA tour. The change was prompted by the wish for a 3.28 ratio rather than any doubts or problems with the existing drive. The unit now has 8500 miles with BMW syn oil. I'm going to pull it apart this winter for a close inspection. Based on my thoughts noted below, I'm toying with the idea of experimenting with Exxon turbine oil. This oil is used both in turbines and extremely heavily loaded gearboxes. I have no doubts about the oils ability to lubricate or its longevity. I'm not sure that the seals can tolerate the oils makeup. I'm going to immerse a seal for a few months and see how it holds up.

[Quote from an earlier correspondence]
Bingo !!! a light bulb went on in my head and I thought about my experiences as an aircraft mechanic. You are right, light weight synthetic is the answer.
I remember a particular lecture given during my formal training as an A&P. (years ago) A radial engine uses large ball bearings on the prop output shaft. These bearings appear to have virtually no lubrication. The instructor explained that a large heavily loaded ball bearing would self destruct if supplied with too much oil therefore a fine mist spray is used. He explained that a flood of oil would simply be pushed away by the rolling balls.
The bike does not have the luxury of a mist lubrication system but a thin synthetic oil would have less tendency to be pushed out ahead of the advancing balls.
Non believers will say that the thin oil will not handle the shear loads on the gears. Wrong !!!
Large turbo-prop prop reduction gearboxes incorporating both large ball bearings and helical gears are using water thin synthetic oil.
Loads involved -- 1500 - 2000 shaft HP at 1700 rpm and dealing with enormous gyroscopic loads generated by the prop.
Using regular gear lube, I'll bet that the large final drive bearing is cooking from oil starvation.
Oil everywhere except where its most needed.
If I were to post this, it would probably be a case of "Let the flogging begin." or "Oh great another oil thread!"
Thanks for jogging my memory.

Myrl Stone
[End quote]

Motard

[cruisin]

At the risk of jinxing myself; I have been using Mobile 1 syn. 75/90 in the final drive on my '98 RT for 61K now. Having purchased it used with 22K that makes 83K with the original final drive still in tact. YMMV :wow

[Mr. Frank]

At the risk of jinxing myself; I have been using Mobile 1 syn. 75/90 in the final drive on my '98 RT for 61K now. Having purchased it used with 22K that makes 83K with the original final drive still in tact. YMMV :wow

I've used synthetic for over 50K miles, too. I'm just passing on the European and Canadian recommendation to use dino that Paul Glaves transmitted in Vermont. I put in the 80W90 GL5 dino as soon as I got home.

[cruisin]

OK this has me really curious now, (and a little concerned). I don't personally know Paul but have read enough by him and about him to know he wouln't make false statements about something so important. I would now have to ask is there imperical data to back up the "seems like" deal or is it just a passing observation? Inquiring minds want to know. Paul you out there? Do you have data to back up the "seems like" ("He said that seemed to be one factor in the high failure rates.") I'm not doubting your word, but I am sort of skepical without organized data to back up a seat of the pants observation.

[pjones]

2002 R1150GSA with 48k miles, I purchased at 31k. Noticed metal filings when I changed the drive oil , refilled with synthetic (just like I did at 36k). Next day went on a 200 mile ride and noticed a couple light "clunks" like I had ran over a small rock as I got close to home. Pulled into the garage and there was oil leaking from the drive seal. The wheel was clean, meaning the seal failure had just happened. The bearing race was shot, and one side of the outer race was worn through the hard surfacing. Gears were still good, as was the small roller bearing on the other end of the carrier hub.
Shocked when I read the price of a new bearing in Bob's catalog: $124 !! The old bearing had a marking of 134VB, I assume it is SKF. Has anyone bought a bearing through a bearing supplier instead of BMW? Too bad it failed, but why overcharge for a bearing that fails prematurely?

[PGlaves]

I do not have a boat load of data regarding these failures. If anybody does it would be BMW,AG and they aren't talking, except to say - and I quote what I was told by a BMW tech-rep at Vermont: "The 17 ball bearing was supposed to fix the problem."

As for the synth vs. dino issue. BMW specs 90w non-synthetic GL5 rated oil for this application. They sell both a non-synthetic and a synthetic oil with their label. A number of people have made the simple observation that the rather sudden increase in the incidence of failures of the big ball bearing on Oilhead bikes occured at the same time that many dealerships started routinely filling the final drives with synthetic. That is only an observation and does not prove cause and effect. But, as far as I can determine by asking owners with failures nearly every time I hear about one, there have been far more failures with synthetic lube than with dino. I haven't written down the data but my limited sample is running a ratio of well over 10 to 1. I have no idea what the actual incidence of the use of dino vs synthetic in all of the bikes is, however.

Dino gear lube served these bearings from 1980 until the very late 1990s at essentially the same rotational speeds - and except for the K12LT essentialy the same axial loadings - with very, very few failures. The notion that synthetic is needed doesn't add up.

So - I don't use synthetic in final drives. I don't recommend synthetic in final drives. I believe it is a contributing factor to the numerous failures. So do a number of others I have a lot of respect for. Ask, for example, Joe Katz or Tom Cutter what their opinion of synthetic gear lube in final drives is. When asked my opinion - that is what it is.

Now I have to go wrestle with the final drive on Voni's R1100RS that has 326,000 miles on it. The big ball bearing is fine, but the inner race of the tapered roller bearing has spun on the crownwheel shaft and the 25mm spacer behind the bearing is worn and a bit hammered. So it needs a new roller bearing and needs to be reshimmed. Wouldn't you know it. A different problem.

[BubbaZanetti]

So - I don't use synthetic in final drives. I don't recommend synthetic in final drives. I believe it is a contributing factor to the numerous failures. So do a number of others I have a lot of respect for. Ask, for example, Joe Katz or Tom Cutter what their opinion of synthetic gear lube in final drives is. When asked my opinion - that is what it is.



after hearing your talk at the National and seeing Tom's opinion on the mailing lists, i recently switched mine back to dino at 31K miles. i had my drive apart at 29K for replacement of the big seal (i know you don't have to dismantle it, but i just wanted to have a look in there). everything appeared fine.

[rinty]

This is an interesting topic. Are there any theories on why the synthetic might be causing the failures?

Rinty

[ultracyclist]

These potentially could be knock down - drag out questions, but

1.)What is BMW doing about this matter of "final drives"?

2.) I know that both big brother and members of the MOA board read these posts. Why can't the MOA board take the bull by the horns and have an article in ON -with input from BMW AG, people like Mr. Glaves, and other authoritative parties-that addresses the issues of final drives, lubricants, weight factors an so on? The ON does a nice job on technical articles, warm and fuzzy stories, people profiles, and facilitating buyers' and sellers' transactions. Why not this?

This article would be clasified as a "public service" in that there are potentially many more drive failures out there. An ON article on this subject would raise the level of the magazine as well as the eyebrows of BMW NA perhaps.

I am curious about two more things, but I do not have the time to research them. What are other websites saying about this problem? Are there any members of the MOA who speak/read German and who could look at some of the German rad sites to see if this is occuring in "Rad-land"?

my 0.02

[BubbaZanetti]

This is an interesting topic. Are there any theories on why the synthetic might be causing the failures?

Rinty


less "sticky" it slides off things more easily, like a large bearing, only the bottom half is submerged in the oil

[j-budimlya]

less "sticky" it slides off things more easily, like a large bearing, only the bottom half is submerged in the oil

At highway speed...the oil is flying everywhere in the rear hub....

I don't believe that it just sits there in the bottom

If you just look in the fill hole...and slowly turn the rear wheel. the oil level drops way down, because the oil is being "carried" up on the gear and bearing....

the oil goes everywhere in the hub at highway speed....

[dlearl476]

2.) I know that both big brother and members of the MOA board read these posts. Why can't the MOA board take the bull by the horns and have an article in ON -with input from BMW AG, people like Mr. Glaves, and other authoritative parties-that addresses the issues of final drives, lubricants, weight factors an so on? The ON does a nice job on technical articles, warm and fuzzy stories, people profiles, and facilitating buyers' and sellers' transactions. Why not this?




"VE MAKE ZE PERFECT MOTORZYCLE. IF YOU CONTINUE TO COMPLAIN ABOUT ZE PERFECT MOTOZYCLE, YOU VIL BE SENT TO ZE CAMPS!"

[PacWestGS]

Having had one, and not blaming BMW. I knew this could happen. :stick

I feel that I loaded my bike too heavy (by 40-50 pounds over max), rode it too hard (passing slower vehicles up a hill) and just reached the end of this bearings life span (40-45K miles).

I have talked with others about the "Achilles Heal" of BMW final-drive (Crown Gear) bearing. It's something that needs to be watched and needs to be replaced as a preventive maintenance item. It's a "mechanical part" of a machine that gets used. Like rings and pistons, clutches and rear-main-seals.

Sure, I wish BMW would take the lead and keep this part under "Warrenty" for the life of the bike. But, they want you (like every other auto manufacture) to buy a new bike (car) every four years or less. Or, when the warrenty expires...

Keep it oiled, keep it clean, and if you decide to keep your bike. Expect to replace it sometime.

I don't know why there is so much complaining about something that wears out from use. Sure, you may get 12,000 miles out of it (that may be some other underlying problem) or you may get 120,000 miles out of it, great.

My dealer, and I have a great relationship with them, said it's a 40-45K mile part on the GS and LT bikes. If it's going to go it's going to go somewhere in that range.

What, did you think you could just add gas and ride forever? :lurk


:hide

[Bokrijder]

These potentially could be knock down - drag out questions, but

1.)What is BMW doing about this matter of "final drives"?

BMW has done something to address this problem -- an improved bearing is being supplied. This new bearing has a reduced number of balls and I have heard an improved cage assembly. A reduced number of balls within the same dimensional limits should mean more room between each individual ball. It is logical that this new-found empty space might be occupied by oil. Oil is good - Dino or synthetic. Some are asking, " If the old style worked in the past, why should a new style be required?" Who knows? If this new bearing solves the issue, does it matter?


2.) I know that both big brother and members of the MOA board read these posts. Why can't the MOA board take the bull by the horns and have an article in ON -with input from BMW AG, people like Mr. Glaves, and other authoritative parties-that addresses the issues of final drives, lubricants, weight factors an so on? The ON does a nice job on technical articles, warm and fuzzy stories, people profiles, and facilitating buyers' and sellers' transactions. Why not this?

As I remember ON did print an article on this subject not too long ago. Paul just presented an excellent post. Note that he used the terms, this does not prove cause and effect and this is my opinion. Paul's honesty defines the difference between a "respected expert" and an "expert" I have yet to hear a respected expert make a bold and definitive declaration as to why this phenomenon has occurred. It could be a number of disassociated factors and causes all of which manifest in a common failure. An example - BMW installed a number of substandard bearings - Some ham fist in factory assembly botched the build up - Some hammer mechanic in the field botched a bearing replacement - a defective batch of oil, synthetic or dino, reached dealers shelves - an owner or mechanic used a grit contaminated funnel in refilling the gear case - plain old wear and tear and finally s--t happens. Any one of these factors could culminate in a bearing failure. Some more premature than others, but a failure in any case.


This article would be classified as a "public service" in that there are potentially many more drive failures out there. An ON article on this subject would raise the level of the magazine as well as the eyebrows of BMW NA perhaps.

Let's consider that BMW's available improved bearing has solved the problem. A "Lets get to the bottom of this" article printed after the solution is in place would probably indeed raise NA's eyebrows. [edit - only time will tell if this new bearing is a solution ]


I am curious about two more things, but I do not have the time to research them. What are other websites saying about this problem?

Yes it has come up , but not to the extent that one might imagine. I did cruise the sites a few months ago. One owner had gone to the end of hiring a bearing expert to analyze his failure. A highly detailed condition report was offered, but only vague conjecture as to why the failure had happened, sound familiar? One thing that did stick in my mind is that the bearing expert stressed how easy it is to damage the bearing during the installation process.

.02s more

Motard

[ultracyclist]

I do indeed remember Paul's article.

If the other article was before November, '05, then that was before I was a member.

[Bokrijder]

I do indeed remember Paul's article.

If the other article was before November, '05, then that was before I was a member.

Ultra,

Anton is running a very interesting and informative series in RA's current OTL issues. Excellent reading, check it out.

Motard

[SIBUD]

What, did you think you could just add gas and ride forever? :lurk
:hide


Yes I did.

[rado360]

Iv'e been told by Max bmw that the 17 ball bearing is no longer availible,any body else hear this from the dealer?

[cjack]

Iv'e been told by Max bmw that the 17 ball bearing is no longer availible,any body else hear this from the dealer?

They were out of stock for awhile, but now are back. For a while, the parts depot was shipping the rest of the 19 ball when you ordered the 17. These bearings are listed as being replaceable both ways. That is, the 19 ball part is considered just as appropriate as the 17. Afterall, the 19 ball bearings carried our rear drives to 200K miles and beyond for many years. Lately, the 17 ball ones have started coming though.