Loose bolt at Underside of Alternator Belt Drive Cover

[Grey Beard]

I have been crawling about under the bike to electrically connect a Zumo GPS and some LED running lights.

Noticed a loose bolt hanging out of the bottom of the black plastic looking oval shaped cover at the front of the engine. I am guessing this is the alternator Belt Drive Cover.

The bolt is hanging through one of the drain holes, dry, no oil, etc). Looks about 5mm diameter and I am wondering where this has come from?

I haven't tried to remove the cover as the bike is under an extended warranty and I guess I shouldn't mess with it. Any ideas what this is likely to be from/how serious and how quickly I should see the local dealer about it. Bike is April 2008 with 7,300 miles, but I wish to do a trip over to Scotland in 2-3 weeks. Had a quick look at the Haynes Manual.

Thanks for any advice.

Grey Beard

 

[forest biker]

I have been crawling about under the bike to electrically connect a Zumo GPS and some LED running lights.

Noticed a loose bolt hanging out of the bottom of the black plastic looking oval shaped cover at the front of the engine. I am guessing this is the alternator Belt Drive Cover.

The bolt is hanging through one of the drain holes, dry, no oil, etc). Looks about 5mm diameter and I am wondering where this has come from?

I haven't tried to remove the cover as the bike is under an extended warranty and I guess I shouldn't mess with it. Any ideas what this is likely to be from/how serious and how quickly I should see the local dealer about it. Bike is April 2008 with 7,300 miles, but I wish to do a trip over to Scotland in 2-3 weeks. Had a quick look at the Haynes Manual.

Thanks for any advice.

Grey Beard

The only bolts that size underneath the belt cover , is the bolts off the balancer shaft cover plate , maybe one has came loose

 

[TeaPig]

Take the cover off and look, it's your bike after all, though it's a bit fiddley getting at the ones at the top of the cover. There's not much under there other than the alternator drive belt and pulleys but there are a few short pins such as the ones holding on the crankshaft cover plate. If it's one of those it needs putting back

 

[Grey Beard]

Take the cover off and look, it's your bike after all, though it's a bit fiddley getting at the ones at the top of the cover. There's not much under there other than the alternator drive belt and pulleys but there are a few short pins such as the ones holding on the crankshaft cover plate. If it's one of those it needs putting back

Thanks TeaPig & Forest Biker.

Yes, it is a bit fiddly with the crash bars and I think exhaust balance pipe also. Is there a gasket there as well that I would have to renew, or is it a plain joint on the cover?

Grey Beard

 

[forest biker]

Thanks TeaPig & Forest Biker.

Yes, it is a bit fiddly with the crash bars and I think exhaust balance pipe also. Is there a gasket there as well that I would have to renew, or is it a plain joint on the cover?

Grey Beard

Theres an o ring on the balancer shaft cover , but you shouldnt have to take it off to worry about that if theres just one bolt come loose , or do you mean the the belt cover thats just fit straight onto the main case no gaskets or anything

 

[Grey Beard]

Theres an o ring on the balancer shaft cover , but you shouldnt have to take it off to worry about that if theres just one bolt come loose , or do you mean the the belt cover thats just fit straight onto the main case no gaskets or anything

Thanks, I was referring to the big cover, which is trapping the said loose bolt. I guessed it wouldn't have a gasket, since it has two drain holes at the bottom. Makes it a bit easier.

Really must try and convert some of the torque keys to use in a socket set for sanity and knuckle preservation!

Grey Beard

 

[Spike]

I changed all mine to Stainless steel allen bolts when I took mine off for painting.
There is no gasket on the cover so just undoo all the bolts and take it off put back the little bolt that came out and replace the bolts with what ever you wish, I bought mine from a guy on ebay.

spike

 

[Grey Beard]

I changed all mine to Stainless steel allen bolts when I took mine off for painting.
There is no gasket on the cover so just undoo all the bolts and take it off put back the little bolt that came out and replace the bolts with what ever you wish, I bought mine from a guy on ebay.

spike

I had a go at removing the alternator cover and recovered the loose bolt inside. It is exactly the same as the bottom three bolts on the cover.

However, I was not able to remove the cover for a good look, as I need to remove/swing out of the way, the crash bars (1200GSA) and at least one bolt is difficult to access on top of the left cylinder.

I was going to slacken the crash bar bottom bolts on each side (but hope these are not supporting the engine? (Doesn't say anything about that in the Haynes manual).

Do people use a socket set with torque bits to access these more inaccessible fastenings. I don't want to remove the petrol tank if possible.

Grey Beard

 

[Kenny Rodkiss]

will be one off No.5 that has fallen out.

if its the bmw engine bars you can still remove the cover with the bars in place, yes its a tight sqeeze and the cover catches on the alternator pully but it will come off.

 

[Grey Beard]

will be one off No.5 that has fallen out.

if its the bmw engine bars you can still remove the cover with the bars in place, yes its a tight sqeeze and the cover catches on the alternator pully but it will come off.

Thanks for the diagram. Where is that sketch from? Much clearer than the Haynes Manual photos.

I can give the cover another go tomorrow (with a bit more persuasion!). It's always the same when you start these jobs, which look simple, at the weekend and then either break something, or need a specific tool to do the job - and of course the shops are closed!

Not screw #5 but probably screw #8, I think, from your sketch. (they seem to number the screws specifically, so that the two at the top of the alternator cover are different from the three at the bottom.

Thanks

Grey Beard

 

[Kenny Rodkiss]

Yes the two screws at the top are different than the other three.
The top two screw into the plastic part No.10 the other three screw into the alloy cover No.1
If it was one of the bottom three it would just fall out and never be seen again so it would have to be one of No.5
Pic came from www.maxbmwmotorcycles.com/fiche/fiche.aspx

 

[Grey Beard]

Thanks for that resource link. Very useful.

I understand that if one of the three bottom bolts fell out, it is gone forever. However, bolt #8, which I think is the same as the bottom three external cover bolts is located (or appears to be located) inside the alternator cover. It looks like they (I presume two bolts) are holding belt guard (part #10), etc.

The original BMW fiche does not list part #5 (screw) so maybe these are part #8 also.

Hopefully I will be able to remove this alternator cover and sort the problem.

Thanks

Grey Beard

 

[Grey Beard]

OK, removed the alternator belt cover without any more fiddling with the crash bars. The loose bolt was from the left side of the belt guard. Thanks for all the help

There was no balance cover plate on this engine, so I was a little confused. The system looks like:

This is an American source but states manufacture 10/8 - 2/11, whereas my bike was registered 04/2008. Seems to be different to the American production. But my Haynes Manual also shows the balancer cover plate!

Grey Beard