Adjusting the Alternator belt

[macd]

A basically similar set-up was often used to allow adjustment of gear and rear brake pedal heights on racing motorcycles. A variation on the theme is to have a threaded rod, left-hand at one end, right hand at the other with a hex in the middle, the working length being adjusted by ball joints (rose joints). M6 is the usual size, although M8 might be more apt for your application.

 

[reeac]

I seem to remember an item (in PBO?) where a reader had used a turnbuckle in place of the standard adjustment arm on his alternator to facilitate fine adjustment. Looked like a neat idea if one can find a turnbuckle of suitable size, but I haven't tried it.

The neatest system that I've ever seen was on a BMW where the slot in the arm was formed as a rack on one side whilst the shank of the locking bolt had teeth so creating a rack and pinion. You turned the bolt head with one spanner to set the belt tension and then locked it at that point with another spanner on the nut. I find, though, on my VP2002 that in order to get enough belt tension I need to push a long screwdriver through the slotted arm until its end bears against the engine block and then press it against the alternator locking bolt housing. With a long enough screwdriver that gives plenty of leverage.

 

[Heckler]

The neatest system that I've ever seen was on a BMW where the slot in the arm was formed as a rack on one side whilst the shank of the locking bolt had teeth so creating a rack and pinion. You turned the bolt head with one spanner to set the belt tension and then locked it at that point with another spanner on the nut. I find, though, on my VP2002 that in order to get enough belt tension I need to push a long screwdriver through the slotted arm until its end bears against the engine block and then press it against the alternator locking bolt housing. With a long enough screwdriver that gives plenty of leverage.

Exactly, why complicate a very simple thing!
Stu

 

[Hydrozoan]

Exactly, why complicate a very simple thing!

I don't think it's greatly complicating to have a turnbuckle or similar to hold the alternator just where you want it while you check the belt depression before tightening up all the bolts. Not a big deal - but in the PBO article I cited, not a big cost either.