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Alternator Belt Adjustment Tool w/ Pics

Posted: Mon May 23, 2011 8:32 pm
by Sunbeemer
Here's a cool tool I read about a while ago that makes changing/adjusting our alternator belt much easier. I'll keep it on the bike with my spare alternator belt...

To torque the 8mmX1.25mm adjustment bolt that tightens the alternator belt, I bought a 8mm X 1.25mm SS cap nut at Home Depot that had a 9/16"" deep (blind) well that I screwed a ~1/4"-long piece cut off the same size bolt with a slot hack-sawed across one end to screw it to the bottom of the well with a flat-blade screw driver. I thnk this is like the special tool BMW sells for this purpose...

To replace the belt after removing the front engine cover, loosen the upper and right-hand alternator mounting bracket bolts and remove the nut from the adjuster bolt on the left-hand side of the alternator mounting bracket. Then screw this cap nut on that bolt and tighten the new belt to spec by tightening it to 8nm. Then, holding that, tighten the other two nuts to hold the alternator tension on the belt while you replace the cap nut with the regular nut. Fortunately, the adjuster bolt tightens the belt as you tighten the cap nut, so after it bottoms out on the bolt end (reason for the insert), you can apply the required torque to tension the belt.

While the allen head on the other end of this bolt can be used to tension the belt with the correct tools, it is tedious without removing the tank and can cause cursing. This is easier and can be done with a 13mm or 1/2" wrench, so as long as you have this little cap nut handy, you can easily do it on the roadside with tools you already have, and enjoy the ride even more knowing you can change this belt whereever you have to. :D

Got nuts?

Re: Alternator Belt Adjustment Tool

Posted: Tue May 24, 2011 10:51 am
by sweatmark
Pic of this adjustment tool would be much appreciated.

Re: Alternator Belt Adjustment Tool

Posted: Tue May 24, 2011 11:56 am
by Boxer
IT'S INVISIBLE! That's what makes it so great! LOL :p

Re: Alternator Belt Adjustment Tool

Posted: Tue May 24, 2011 9:29 pm
by Sunbeemer
Here are the best pics I could get...I'm no photographer...

This is a stainless steel 8mm diameter X 1.25mm threaded cap nut (aka an acorn nut)
Image

This is the inside of the nut showing (hopefully) the 8mm X 1.25mm bolt I cut off, broached, and screwed in to partly fill its hole so it would bottom on the end of the belt tensioner bolt before tightening against the engine.
Image

Satisfies all my criteria: easy, fast and cheap (but not invisible)!

Re: Alternator Belt Adjustment Tool w/ Pics

Posted: Wed Jul 20, 2011 11:01 am
by LeeH
Sunbeemer - thanks for posting this thread and saving me $200!

Here's a twist I used: for the internal spacer I found a metric setscrew at the local hardware store. It's 8mm long (just over 1/4 in) and uses a 4mm hex driver. No cutting or slotting needed.

Cheers - LeeH

Re: Alternator Belt Adjustment Tool w/ Pics

Posted: Thu Jul 21, 2011 12:53 am
by iowabeakster
:smt023 Thanks guys.