Musings on final drive concerns

I’ve done quite a bit of thinking and research on the matter of BMW final drive (FD) failure(s).  There is much fragmentary documentation and discussion already on the ‘net  . . . some is factual, researched and engineering pertinent.  A smaller amount is fanboy emotional and ignoring of evidence.  Let’s address some ‘knowns.’  First, what is a failure?

Yours will be in a failing state long before it looks like this. Look for flecks of hydraulic fluid on the rim and/or seepage of hydraulic fluid from the boot. You or your mechanic should be inspecting this at about every 6K or no worse than 12K miles.

I’ll define “failure” as a defect (either in parts manufacture or assembly) that compromises final drive operation in a time frame considerably shorter than its prescribed lifetime.  I’ll define the final drive unit as the rear ‘hub’ that your wheel attaches to.  If you own a Paralever BMW motorcycle, you have this type of hub.  Inside your hub, the ‘final drive’ is composed of gears, hydraulic fluid, bearings and seals.  Most final drive failures point to the rear drive unit (RDU) was assembled with too much preload or defective bearings.  Two indicators that the FD crown wheel bearings are going bad are shiny metal flakes in the rear drive hydraulic fluid and roughness felt during wheel rotation.   In some cases, some of our fellow beemer brethren, have had a replacement final drive fail a second time, due to the same improperly shimmed crown gear.  Meaning, there are some current BMW riders with 50K-80K miles on their bikes that are on their THIRD final drive.  Many riders can go 100K-150K without a final drive problem, yet there is a sizable enough population of owners who have either spent sizable coin or had warranty replacements of final drives.  BMW’s secretive data-gathering and non-committal as to the scope of the problem with US dealers, compounds issues too.

I think there is a separate but related maintenance issue.  A competent dealer (or independent) mechanic will wiggle your rear wheel at ‘3 and 9’ and ‘6 and 12’ (think of a clock) to determine how much wheel movement there is.  There is not much wiggle or deflection allowed.  In fact, more than a millimeter of side to side or up and down movement is cause for concern.  It means one’s bearings are out of operating spec and will likely and progressively get worse.  Depending on the bearings and if you’re lucky, they might be removed, readjusted and simply reinstalled.  If not, they will have to be replaced.  The mechanic will also loosen and retract the plastic boot.  And hopefully, no fluid leaks out.  In my case, a pool of hydraulic fluid spilled out, covering about a 2×4 inch area.  A seal was failing/had failed.  Seal leaks can come from the transmission output seal leaking gearbox oil down the inside of the swing arm and out into the boot. The FD can also leak oil out past its input seal, sometimes called the pinion seal.  Fixing either of these is relatively straight forward.  If, however, the FD is leaking oil past the “big bearing” seal located where the FD mates with the real wheel (under the rear disc brake), you may have a third seal replacement to contend with.

Regarding the ‘rear wheel wiggle issue,’ I’ve owned two R1100R bikes (not RTs or heavy GS’s) and both needed replacing of final drive related bearings.  In the most recent case, it was the pivot pin bearings.  (I can’t recall the prior R1100R from some years previous . . but would bet, pivot pin bearings also.)  In the earlier case, those bearings were shot by 18K miles (which I attributed to the crummy Washington DC area roads) and in the most recent case, at just under 39K miles, where the bike has been in FL for the last 20K or more miles.  On my R, those were road miles with no passenger hauling, nor off-roading or commuting on salty winter roads.  That’s not much mileage in either case to suffer bearing failure.

Those Paralever owners who start to see ‘flecks of hydraulic fluid’ on their rear wheel rim or notice a small inconsequential seepage under the plastic boot . . . that is your bike’s way of saying, “there are issues you need to deal with fairly soon.”  Lastly, if these signs are ignored, are you on the path to a final drive failure?

I think . . . probably.  In summation, two issues-  there’s a small but known amount of final drive units with improperly shimmed crown bearings that have found their way onto BMW Paralever motorcycles over the last 15 or more years.  I’ve heard “around 4%” of units fail. Secondly . . . improper or ignored maintenance can lead to a final drive failure too.  Most units make it into 6 digit amounts of miles . . . . but maybe replacing a set or two of bearings and seals along the way is par for the course.  Is the Paralever design an engineering weakness?

Hard to say . . . . our friends in Munich would say, (for the bike’s first 36K miles and maybe 48 months) you have bought unique and superior motorcycle engineering that is capable of 175K miles or more, but requires you to conduct diligent and ongoing maintenance all along the way.  In my case, I’ve paid a $1,000 on two bikes to replace FD bearings and seals.  (In neither case, would one say I had a FD failure.)  Would I have paid similar repair costs on a couple of Japanese bikes?  (Chains, sprockets?)  I doubt it.

To close, one thing I’ve yet to see, anywhere . . . is how rear suspension (strut/shock) functionality works with the Paralever suspension.  One would think a rear strut on its final legs, would not meet preferred Paralever functioning requirements.  But I’ll leave that issue for another day.

For further research:

Sept 2008 issue of Motorcycle Consumer News, Bill Shaw, writer, p. 32

http://www.largiader.com/paralever/

http://bmwra.org/otl/final-drives

http://www.bmwlt.com/forums/bike-talk/41805-final-drive-failure-bmw-nov-2008-a.html

http://advrider.com/index.php?threads/nhsta-opens-investigation-into-bmw-final-drive-failures.761531/

7/30 Group Ride

Sunday, July 30, some of the Space Coast BMW riders rode down to Marsh Landing. Dan, from Sales at Power BMW Motorcycles, Palm Bay rode with us too. He showed us a different way to get to the Marsh which added more curves to the ride (didn’t think there were any!)  A good time and we managed to avoid the rain.  Also making the ride–   Marty (back from his National Rally pilgrimage), Ed J. & Debbie J and two new riders, Elian and Brian.

From Ed’s helmet cam!

6/24 Ride to Sebring

Tom Blake of the Florida Motorcycle Sport Touring Asscn invited local beemer riders to ride to the Sebring airport restaurant for a Saturday brunch.  Melbourne area riders met-up at the RaceTrac gas station at Malabar Rd and Babcock St (just east of I-95).  We rode down to Fellsmere, picked up another FMSTA rider and proceeded to the Sebring airport, getting there about 9:15 am.  The airport restaurant is barely 150 ft away from one of the race course turns . . . one can practically hear the echoes of an Audi Diesel or Porsche 911 hurtling around the circuit.  Their group had riders from south Florida, Gulf-side and NW of Orlando in attendance.  A good turnout.

We had a pleasant 90 minute brunch with 20+ FMSTA members, the food and service recommended by all.  Once finished, we broke up into smaller groups for the trek home.  The ride back was a bit challenging with upper 80’s and low 90’s temps and being all geared up, full face helmets, etc.  The effects of dehydration were in evidence (loss of concentration) but thankfully a “pit stop” at Yahoo Junction remedied that problem. We encountered some of our other m/c brothers of the V-Twin variety . . . ‘do-rags, leather vests, wallets on chains, half or no helmets . . . quite the contrasting approach to safety gear!  But, it’s all good, right?      🙂      Once in Palm Bay, we headed to BMW m/c dealer (again!) for air conditioning, water and to kick some tires!!!

For future planning-    One of the FMSTA regional areas is planning a ride to the Marsh Landing restaurant in Fellsmere, July 15, 9:30 am  for breakfast.  It would be logical for us Space Coasters to join up with them. (We’ll inform local riders if we intend to ride as a small group down (necessitating earlier meet-up time in Melbourne) or if we’ll just meet-up at ML. TBD.)  If you ride German, British, Italian, or a Japanese sport tourer or standard, and are not a regular rider with us yet, or haven’t come by on Wednesday evenings, then join us for Wednesday dinner or the Saturday ride.  Or preferably, both!

5/27 Ride and Meet up

To area beemer owners and enthusiasts:

Last Saturday’s group ride was quite well attended  . . . numerous years and styles of BMW bikes joined up.  We rode down to Marsh Landing in Fellsmere for breakfast.  For trip home, en masse, we rode north on SR 507 (which becomes Babcock) and headed for the new BMW dealer.  We spent another two hours looking at some of Munich’s latest & finest two wheeled machinery.  David (GM), Daniel (Sales) and Shawn (Parts/Service) could not have been nicer, spending much of their time with us.

https://www.facebook.com/powerbmwpalmbay/?ref=page_internal

Wednesday night’s (5/31) Jason’s Deli meet-up was also best attendance in a long time. Local rider buzz (thanks to new dealer) is definitely on the increase.  David, Dan and Shawn came by for dinner and we had a nice talk with them about motorcycles, riding in FL, SEC football and  .  .  .  (of all things) hockey!  If you haven’t been by Jason’s in Melbourne on Wed evening and have a BMW or other Euro bike, or are thinking about getting one; stop by and have dinner with us.

Shout-outs to Jim and Camille (who rode their LT), Bill, who came to the group ride and Jason’s Deli on his R100RT and Terry who came over to Jason’s on his GS Adventure.  Nice folks and hope to see ya’ll again on future rides and Wed. evenings!

Game changer for Space Coast beemer fans

   

Who’d a thunk it?  Melbourne/Palm Bay and adjoining areas have our own BMW motorcycle dealer.  Say what!  No more braving the traffic jammed Orlando metropolis . . no more pilgrimages up or down I-95 or cross peninsula treks . . . but here in our own backyard!!!  David (the GM), Dan and Shawn are great guys.  Maybe later expansion into Triumphs too.

FRF Powersports      190 Interstate Crt., SE      Palm Bay, FL  32909       321 215-2065

http://bmwmcofpalmbay.com/

Space Coast BMW Riders on the long ride

Glenn B. and Marty S. departed the national BMW Rally for trip back home to Melbourne.  Join us at Jason’s Deli Wed eve., to hear stories from the road . . . I’m sure they have a few to tell!

 

 

 

 

 

 

 

Additionally, Chuck B. (our resident Florida to Alaska rider) is riding throughout eastern Canada to visit historic lighthouses.  He’s currently in Nova Scotia.  Certainly an interesting trip and different riding environment than Glenn and Marty have faced.  Those of us back here wish him all the best.

Melbourne “wrench” resource

Many thanks to the techs at PJ Cycles at 500 North Drive, Melb. 32934  Phone 321/241-4977.  They did some electrical troubleshooting on my R1100R and were very gracious about total charges.  These guys are a decent BMW knowledgeable resource and easy to work with.  Yes, a V Twin shop at first glance, but they can get your beemer going!  Saw a Kawasaki and Ducati in there too.  Highly recommended.

http://pjcycles.us/home/3723847

 

Feb 3 Ride report

Six riders turned up at Sam’s Club gas station for this ad-hoc weekday ride and decided to ride to the Griffis Cafe on SR441 in Keenansville for lunch.  The weather was great, sunny with temps in the mid-70’s.  We went west on SR192 to SR441 then south until we were stopped cold by a line of traffic for an accident about 1/2 mile south.  A tractor trailer dump truck had overturned and the recovery efforts were blocking the road.  We walked around, communed with nature, chatted with other drivers and waited for about an hour until the road reopened.  Turned out we were only 2 miles from the Griffis Cafe, which was packed with others waiting for the traffic to clear up.

We ordered and talked for about an hour before we got our food, but it was OK since we enjoyed the conversation.  Two of our riders had been there the day before and had raved about the food.  On our visit, they were slammed with customers and we were about 45 mins behind schedule.  Leaving there we proceeded south to SR60, east to CR512 to Fellsmere, then Babcock St. north into Brevard County and home.

All in all, a good ride of approx. 125 miles on a pleasant day.  The periodic weekday ride does show promise and we’ll continue them.