Changing the alternator R1200GS 2009

iainhwilson

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Yesterday I changed my alternator on my 2009GS. Although I knew it had a cracked casing, it was still running.

Just in case anyone plans a similar job, I thought I could outline some points as some of the original descriptions are not so easy to find now.

Tank and beak off; expose belt and remove (during this phase the heads came off 2 small bolts from the upper cover). Put jack under engine, disconnect electrics from front ESA shock from connector and move out of way along with the fluid lines - this looks more complicated than it was, as it all unbolts easily. Remove and replace alternator from the front. Put back together. Search for where the bolt left over should go. The jack is useful to adjust the height to get the lower shock bolt in and support the weight with the shock out. Copious amounts of penetrating oil used. Beer.

Tonight I took some photos of the inside of the alternator for interest - definitely worth avoiding the pressure washer on this area.
 

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Nice shade of rust brown internally!! JB weld and a bit of wire wool and it'll be grand... not!

It's a job I dread when the time comes but your explanation makes it sound easier than I thought it would be 👍
 
The ESA wiring disconnection is mentioned but can the shock remain in place?
 
Thanks for sharing this. Very useful. I fear I may need hiking my brand new alternator out. Hoping not 🤞🏻

Without the bike in front of me, I'm unclear if you can unbolt the shock at the top and swing it out of the way? I'd probably remove it entirely (I've had it out twice in the past you'd think I'd remember!) but since you're fresh from the rebuilt, your feedback would be welcomed by many 😊
 
When I swapped mine on my GSA I removed the ESA shock and got it out forwards but I’m sure somebody said removing the fuel tank is easier ?

Anybody know for certain ??
 
Remove tank - support bike
Unbolt bottom of shock - lots of penetrating oil. Back/ forward / spray and repeat.
Wedge something at top nut of shock to undo without stress on fluid pipes (I used a tyre lever).
Undo 3 bolts with captive nuts and 2 with loose bolts holding front shock fluid reservoir and ?ECU. Unplug lead from loom sitting on top of ‘main electronic units’. Shock can now be removed / pulled out to the front. Needs to be well out of way to get the alternator out.

Not sure about non-ESA bikes - maybe shock is smaller; but should be even easier to remove.

I’m not particularly good at this stuff, so don’t be to concerned about complexity. The upper route looked a bit more complex and I didn’t fancy straining any 16yo electrical connections.
 
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Nice one. Have done the same job on my Tiger Explorer 1200. Not straightforward. 👍
 
Didn’t have to touch the front shock when i did my Bosch alternator conversion. As I remember after removing the tank just partially lifted the ecu and wiggled it out, no real dramas.
 
Didn’t have to touch the front shock when i did my Bosch alternator conversion. As I remember after removing the tank just partially lifted the ecu and wiggled it out, no real dramas.

Correct. That’s the easiest and quickest way to remove the alternator.
Tank off, undo required bolts and remove alternator up and backwards from the bike.
 
Correct. That’s the easiest and quickest way to remove the alternator.
Tank off, undo required bolts and remove alternator up and backwards from the bike.
How interesting. When I looked at it - in the last days, with the tank off, at home (thank god) that's what I first thought.

But after getting the the bike 'fixed' recently in Metz (see my own posts on the story) I could see a number of badly fitted items - crash bars, wrong routing of hoses and some cables - minor stuff. But when looking at the BMW workshop CD, it instructed to remove the crash bars, front shock etc and take the alternator out forwards. This is clearly what the dealer did - the young mechanics were following the same CD I have 😄!!

So thank you Steppers, I'm interested in what you say. I may be needing this info again soon 🤦🏻
 
I've changed a few alternators now, I've never removed or even loosened the front shock...

It's wriggleable out from above by lifting the plastic ECU tray.. On one occasion I couldn't get it out and got bored trying, so I did remove the frame arm on the right side... the 300mm ish long arm that mounts the ECU as that gave a lot more access.... Certainly easier than removing the shock.

Roger
 
Very useful comments - thanks.

Hopefully the thread will be useful to those who follow, which was the reason to re-start an old topic.

Choice of techniques….. mine is now no 3, but still easy enough!
 


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