Alternator belt fitting

[Buckingham]

The alternator belt failed on my 2012 twin-cam. I think it may have failed at least in part due to damage to the crankshaft pulley. My assumption
is that someone has tried to use something hard to lever the belt over the pulley and caused damage the damage in the 'photo.
I fitted a new pulley and borrowed the belt fitting tool from the BMW pipe & slippers club; unfortunately I found the tool very awkward to use as it kept slipping off the pulley. (access is limited & doubtless the tool would work well if the engine was on the bench)
I looked at Normski's video on youtube where he'd used an M6 screw into the pulley to guide the belt onto the pulley; this does work but IMO it drags the belt over the edge of the pulley, which has the potential to damage the new belt.
So I made up a sleeve to fit over the M6 screw which protects the new belt from the edge of the pulley when fitting. It works really well. See pics.
Hope that's useful ?

 

[Pukmeister]

I just cut up a plastic milk bottle into strips to cover the ribs on the pulley, put the bike in 6th gear with main spark plugs removed and slowly rotated the rear wheel with my boot. The belt loops over the alternator and by rotating the rear wheel the belt slips/stretches into place over the crank pulley. Once in place, keep rotating the rear wheel and slip the plastic strips out.

Job takes ten minutes, no special tools required.

 

[Steptoe]

I use a very long handled spanner on the crankshaft pulley, as I turn it the handle revolves around the pulley (obviously) but it also guides the belt over the pulley at the same time. Takes 30 seconds, and I’ve done hundreds of them over the years,

 

[DaddyPaddy]

Just out of interest, at what intervals is the belt replaced?

 

[Steptoe]

Just out of interest, at what intervals is the belt replaced?

24k miles or 5 years. But I’ve had bikes in 10 years old with low miles and the belt still
looked like new, but more importantly was still flexible and “rubbery” and hadn’t gone hard.

 

[Pukmeister]

I used to carry a spare belt plus the plastic strips in the aftermarket tool bag on my crash bars. I always carried a set of small torx bits in my toolkit for the fuel pump controller etc that would also fit the belt cover screws.

My rationale was that I could use my method to easily change or replace a belt at the roadside if necessary with the minimum of tools.

Thankfully I never had a belt break on me (or my riding pals) but at least I was covered......A bit like Wappings pound of butter to ward off Elephants, you can bet if I didn't carry a spare I would find myself stranded in deepest rural France on a Sunday.

 

[Andygbsmith]

As Above, cut up a plastic bottle

 

[Pukmeister]

Nobody has mentioned it yet so I will.....mind your bloody fingers !!! ........(those belts can bite).

 

[DaddyPaddy]

I just cut up a plastic milk bottle into strips to cover the ribs on the pulley, put the bike in 6th gear with main spark plugs removed and slowly rotated the rear wheel with my boot. The belt loops over the alternator and by rotating the rear wheel the belt slips/stretches into place over the crank pulley. Once in place, keep rotating the rear wheel and slip the plastic strips out.

Job takes ten minutes, no special tools

I just cut up a plastic milk bottle into strips to cover the ribs on the pulley, put the bike in 6th gear with main spark plugs removed and slowly rotated the rear wheel with my boot. The belt loops over the alternator and by rotating the rear wheel the belt slips/stretches into place over the crank pulley. Once in place, keep rotating the rear wheel and slip the plastic strips out.

Job takes ten minutes, no special tools required.

Is it a necessity to remove the spark plugs for this job?

 

[landmarkjohn]

Never done it but I would suggest not neccessary if you use Steptoe spanner method or if you have help.

It's one of those ones that it will be easier if plugs are removed but is it worth the effort of the extra work?

 

[Pukmeister]

Is it a necessity to remove the spark plugs for this job?

Stick your bike on the centre stand in 6th gear, lay next to the bike, try turning the rear wheel with your foot and find out.

 

[seahorse]

If you got the right size spanner or socket it's a piece of piss and no need to remove plugs. Can't remember the size, maybe 36mm.

 

[Pukmeister]

I never had a 36mm spanner in my bike tools, it wouldn’t fit into the little toolbox behind my pannier frames.

 

[DaddyPaddy]

46mm or 1 13/16” no lying down for me

 

[seahorse]

I never had a 36mm spanner in my bike tools, it wouldn’t fit into the little toolbox behind my pannier frames.

Haha, me neither! It's not a job I would expect to be doing on the road. But if you were, as said above, all you need is a spare belt which would guarantee you would never have a problem. On a serious note an adjustable spanner would take up far less space and you can use it to feed the belt on to the pulley as you turn.

 

[GSite]

2 Litre soft drinks bottle seems a reasonable diameter compared to the pully.
Just cut it 15cm or so from the bottom and slip the smaller section over the pulley then ease the belt over. Worked a treat for me.

 

[landmarkjohn]

Can we confirm the nut size for future ref please.

My MY08 nut is M22 x 1.5 according to realoem.com and this is equating to 32MM across the flats?

 

[Slipperyeel]

24k miles or 5 years. But I’ve had bikes in 10 years old with low miles and the belt still
looked like new, but more importantly was still flexible and “rubbery” and hadn’t gone hard.

That reminds me. I'd better do mine! You did mine about 26k miles ago!

Sent from my SM-S908B using Tapatalk

 

[jacksdad63]

46mm or 1 13/16” no lying down for me

The 2004-8 is 34mm, just bought an impact socket as it was same price as standard, about £10 on Amazon. And you need to remove the plugs, takes minutes and much easier not fighting compression

 

[DaddyPaddy]

The 2004-8 is 34mm, just bought an impact socket as it was same price as standard, about £10 on Amazon. And you need to remove the plugs, takes minutes and much easier not fighting compression

34mm Looks a more realistic size, I’ve misread the motoworks parts list earlier, disregard previous post.