Sorry, Another Final drive Question

[Tshader]

2004 R1150RT Three failures around 12,350 miles or so each. First two repairs were the same, same result(you know what Einstein said about that) Here is where my question comes. The last repair as in the first two the crown bearing, and roller bearing were changed along with a seal and o-ring. But in addition the axel bearing was also changed along with the needle sleeve. Could these two differances have finally fixed my final drive correctly? I have over 14,000 miles on this repair and no problems including no metal filings on the drain plug magnet just two days ago. Am I home free, or do I still worry about my next failure??

[Danny caddyshack Noonan]

Maybe the backlash and preload were done to spec?

[Tshader]

That is a possibility, however I would have liked the "Authorized Dealer" to tell me or show on the work order that it had been done.

 

Thanks for your response, Peter

 

tshader

[AndyS]

Who did the repairs?

Was there a warranty with them?

Was it the same wealer who has done the repairs?

[dirtrider]

Morning Tshader

 

The USUAL cause of repeated crown bearing failures on the 1100/1150 final drive is improperly set crown bearing preload.

 

Unfortunately there are a number of repair shops & even some dealers that lack either the expertise, or proper tools, or solid work ethics to set those final drives up properly.

 

If that bearing preload isn't set properly then you end up with the next failure in about the same time frame as the one just before it.

 

 

Unfortunately a number of repair shops know that just quickly stuffing a new bearing in the drive & shoving you out the door that it won't fail again until it is well out of their implied warranty period. Quick money for the shops with the next failure most likely happening far from them & with enough miles to not be their concern.

 

So my first guess would be that your bearing preload wasn't checked or set properly on the previous repairs.

 

 

Next guess, if the repair was done correctly with correct bearing preload being set on the last few repairs then you might have a drive that wasn't machined to specs at initial machining & factory build. The final drive on the 1100/1150 is very dependent on precision machining & stringent quality control. That darn crown bearing has a press fit on it's OD a press fit on it's ID & runs with a lateral preload. Any one of those 3 being slightly out of spec can destroy the bearing after running a few thousand miles.

Unfortunately BMW only publishes the specs on the pre-load with nothing published on the cover bearing bore size or spool tube size.

 

A person that has done a number of final drive repairs & has a "good feel" for what a proper crown bearing press fit feels like might catch a tight bearing during assembly or on the cover spin test after the thing cools down from assembly heating.

 

If that were my drive that failed regularly like yours does I would either find a trusted repair shop with a good history in PROPER final drive repairs (not many around) & have them go though it for proper bearing preload & check for proper bearing bore ID size & for proper spool OD size then do a precision preload setting.

 

Or find a good used final drive & start over with at least a crown bearing replacement & proper preload setting.

 

If someone came to & asked me to design a final drive that had a high potential to fail at low mileage intervals, was very finicky for assembly, was difficult to measure the bearing preload without special tools or special know how, & would have a high failure rate for it's intended usage. I would design one very similar to the 1100/1150 BMW final drive.

 

I'm pretty sure BMW didn't set out to purposely design a prone-to-failure final drive but in their need to end up with a very narrow overall width for single side swing arm packaging & tire clearances they got what they got, high failure rate & all.

 

[Tshader]

Thanks DR and AndyS for you responses. Here is a little more detail on these failures. The first failure was at 21,000 miles on the bike. The crown bearing was coming apart. I was able to catch it in time before there was any serious damage to the final drive. I had that failure repaired by an independent technician who has worked on all my BMWs (4) and is a former BMW trained technician. The second failure was 34,168 miles and was repaired by Foothills BMW/Triumph in Lakewood, CO. These two repairs were paid for by me. The third failure was at 46,549 miles and fell under BMWs two year parts and labor warranty and again repaired at Foothills. However, at no time have I heard anyone talk about setting preload for any of these repairs.

 

Side note. I am pretty much done with BMWs and even though recently retired, hope I can purchase another brand or I will just have to hope I don't have another failure. Or if so, it happens within the two year timeframe.

 

Thanks again for your responses.

 

 

[dirtrider]

Afternoon Tshader

 

If the preload wasn't PROPERLY set at last repair there is a real good chance it will fail again at about the same mileage as last failure.

 

With your failure history maybe, just maybe, the BMW dealer finally checked the bearing preload at the last installation. Problem is, even if they didn't I'm sure if you ask they will say they did.

 

If I were in your shoes I would pull (or have done) the side cover & spool at about 10K from last repair just for an inspection.

 

Or if you are worried about a possible on-the-road failure then remove your final drive & send it to someone trusted (there are a few out there) & have it set up correctly.

 

If you decide to keep your BMW they are not a simple machine to have properly serviced so (IF) you find a qualified tec to work on it that can make it great machine to own.

 

About anybody can repair the BMW but few have the experience & work ethics to do it correctly (this includes a lot of BMW dealers).

I would like to think most BMW dealer tecs have the knowledge to do it right but time is money to them so they seek short cuts to get it out the door & next vehicle on the lift as quickly as possible.

Your vehicle isn't as near & dear to them as it is to you, it's just another quick dollar in their pocket.

 

[AndyS]

.....If you decide to keep your BMW they are not a simple machine to have properly serviced...

 

Hi DR. Is this what you meant to say?

I would suggest they ARE a simple machine to have serviced. I think that's why there is such an active forum for these bikes.

 

+1 to DR's observations about your FD.

I would be tempted to find out the tech that did your last FD and without prompting him, ask him what is involved and see what he has to say about preloading etc.

 

Andy

[cpayne]

Afternoon Tshader

 

If the preload wasn't PROPERLY set at last repair there is a real good chance it will fail again at about the same mileage as last failure.

 

With your failure history maybe, just maybe, the BMW dealer finally checked the bearing preload at the last installation. Problem is, even if they didn't I'm sure if you ask they will say they did.

 

If I were in your shoes I would pull (or have done) the side cover & spool at about 10K from last repair just for an inspection.

 

Or if you are worried about a possible on-the-road failure then remove your final drive & send it to someone trusted (there are a few out there) & have it set up correctly.

 

If you decide to keep your BMW they are not a simple machine to have properly serviced so (IF) you find a qualified tec to work on it that can make it great machine to own.

 

About anybody can repair the BMW but few have the experience & work ethics to do it correctly (this includes a lot of BMW dealers).

I would like to think most BMW dealer tecs have the knowledge to do it right but time is money to them so they seek short cuts to get it out the door & next vehicle on the lift as quickly as possible.

Your vehicle isn't as near & dear to them as it is to you, it's just another quick dollar in their pocket.

Great info here http://www.bmwra.org/otl/finaldrive/ and explains what dirtrider has said and has some photos.

I'm interested in what publication or website has all these gotchas. I don;t remember seeing this in the .pdf of the manual I have. Maybe I'm overlooking it as I'm usually tired when I read the manual.

 

Thanks for bringing this to my attention as I too have an 04 RTP and didn't know about this particular and hoping only Achilles heel

[Danny caddyshack Noonan]

Great info here http://www.bmwra.org/otl/finaldrive/ and explains what dirtrider has said and has some photos.

 

There are one or two videos that demonstrate assembly and preload measurement as well. One is funky, you have to wait for the horse video to finish.

[cpayne]

Great info here http://www.bmwra.org/otl/finaldrive/ and explains what dirtrider has said and has some photos.

 

There are one or two videos that demonstrate assembly and preload measurement as well. One is funky, you have to wait for the horse video to finish.

 

DO you have the links to them?

[cpayne]

Here is a good video explaining the concept of differentials in automobiles but I believe the concept is the same.