Alternator belt - PITA on the 2012..

Topics related to the ownership, maintenance, equipping, operation, and riding of the R1200R.

Moderator: Moderators

Post Reply
deilenberger
Honorary Lifer
Posts: 4210
Joined: Thu May 03, 2007 9:21 pm
Donating Member #: 0
Location: New Jersey USA
Contact:

Alternator belt - PITA on the 2012..

Post by deilenberger »

I did the alternator belt several times on my 2007. That was when BMW spec'd them for 36,000 miles - later reduced to 24,000 miles.

Since my 2012 has 31,500 miles on it - I decided to do the belt before I leave for a trip next weekend. So - I bought one from the dealer ($47 - robbery IMHO.. it's a Conti belt, I'll be looking for a secondary source next time) and figured today I had an hour or two, I'd swap it.

It took me about 1-1.5 hours to do the job on my '07. The '12 took a solid 3 hours to do - and at a few points I was ready to throw in the towel, reassemble and dump it on the dealer.. but I persisted.

What's different? Lots of little things. Things like the mount for the oil cooler. For some reason the old design must have been too simple. They added a level of unneeded complexity, which made removal of the belt cover way more difficult. They also relocated the oil pipe on the starboard side for the oil cooler. On the '07 it went in at the bottom - both sides did. On the '12 - the port side still goes in at the bottom, the starboard side goes in at the top, and has a very short rubber section going to the cooler. The old design you could just lean the cooler forward on the back of the front fender (with a rag to prevent scratching) - this one - not possible. I first tried taking the clamp off the rubber hose and wiggling the hose off. The clamp of course is a one-time use (it got used again) Otiker. Even with the clamp off - the hose was not going to come off the stub coming out of the oil cooler. That's one point where I was about to reassemble and call it a day.. but then I tried removing the bolt holding the clamp that holds the metal pipe up to the top of the engine, and I was able to gently bend that pipe enough to give some clearance behind the top of the oil cooler.

The old belt eventually came off using some cut up soda bottle fed between it and the pulley on the crankshaft. The new belt resisted going on - despite using the Gates tool that I'd bought for just this purpose. I'm certain there is a better tool than the Gates one (it was cheap though..) but - eventually - after many many tries - the tool did it's thing and stretched the belt over the pulley.

Hint - buy a 32mm socket before starting the job. I'm pretty sure that's the size of the crankshaft nut that you need to use to turn the engine over. I didn't - and had to use a 36mm that obviously was loose on the nut making things harder. Having the right socket would have been a joy.. I'll have to start watching at a local flea market for a 32 and a 34 - I have everything up to 30, then I jump to 36 (which I special bought for some motorcycle project..) I need to fill that gap.

Anyway - it's on, and survived a test ride. The old belt looked pretty good - no cracking when reverse-flexed - but the rubber did feel rather dry to the touch and less flexible than the new belt so I guess a new belt was a good idea. The old one could easily have survived to 36,000 miles though. I think I'll plan on revisiting this job at 70,000 miles..

I think the changes in design were probably by the same idiot who moved the oil filler to the opposite side of the bike from the oil sight window.. a change just to make one. My suggestion is - have a dealer do this job if you own a camhead R12R..
Don Eilenberger - NJ Shore
2012 R1200R - I love this bike!
User avatar
dbrick
Lifer
Posts: 721
Joined: Fri Sep 24, 2010 4:36 pm
Donating Member #: 902
Location: Santa Cruz CA

Re: Alternator belt - PITA on the 2012..

Post by dbrick »

That's disappointing.

Sometimes I muse about trading my '07 for a newer R this side of a wethead. I guess not.
David Brick
Santa Cruz CA
2007 R1200R
priors: R50, R50, R69, R69S, R65, FJ1200, K75S, R1100RSL
deilenberger
Honorary Lifer
Posts: 4210
Joined: Thu May 03, 2007 9:21 pm
Donating Member #: 0
Location: New Jersey USA
Contact:

Re: Alternator belt - PITA on the 2012..

Post by deilenberger »

David - it probably would be hugely easier on a lift. As it was - I was rolling around on rubber mats on a concrete floor. That's no place for someone > 70 with arthritis. I'm feeling that project today..

I thought perhaps CRS had struck - and I was forgetting something about doing it on the '07 - so I went to MaxBMW's fische diagrams. The '07 and '12 diagrams are considerably different, and the '12 diagram shows all the new parts they added (to get in the way of the job) on the 2010 camhead revision. It appears that they wanted the rear of the cooler a bit further away from the plastic cover over the alternator belt, and they achieved this by adding a rather complex mount for the bottom. I'm just guessing it was to improve cooling. It may work, since crossing Arizona, New Mexico, Nevada and the Mohave desert on my spring trip, I never was concerned about the engine temperature. But that's just a guess.. could be they have an engineer in charge of increasing complexity too.. :)
Don Eilenberger - NJ Shore
2012 R1200R - I love this bike!
roger l
Member
Posts: 194
Joined: Thu Sep 30, 2010 7:35 pm
Donating Member #: 1
Location: Northfield, Ohio

Re: Alternator belt - PITA on the 2012..

Post by roger l »

When I replaced mt belt on my 2008 I bought a 34 mm socket to change the belt. Unless the nut changed from the hex head to the cam head you will need to buy the 34 mm socket.
I machined some off the face of the socket to allow it to get in behind the oil cooler better. From hearing what problems you had with clearance I might need to machine some more off the front of the socket. I have 17,000 on my 2013 R so I will be replacing my belt sometime next year. Something to look forward to.

Roger L
deilenberger
Honorary Lifer
Posts: 4210
Joined: Thu May 03, 2007 9:21 pm
Donating Member #: 0
Location: New Jersey USA
Contact:

Re: Alternator belt - PITA on the 2012..

Post by deilenberger »

Roger - thanks for that info. I went to Harbor Freight yesterday (slumming..) and looked for a 32mm and 34mm socket - they had 1 32mm 1/2" drive deep impact socket - $5 - and that was it. Glad I didn't buy it. I'd guess the nut hasn't changed - and looking at the deep impact socket, even if it was the right size for the nut, there was no way it was getting behind the oil cooler even cut down 1" or so - which complicates the entire thing. What would be ideal is a ratcheting 34mm box wrench.. I hate to think what that would cost.

Found one: https://www.amazon.com/GearWrench-9134- ... B000HBDW7U = $42.50. Since I doubt if I'll ever do this job again myself, I'll pass on this I think..
Don Eilenberger - NJ Shore
2012 R1200R - I love this bike!
Post Reply