Alt belt tensioner idea

[veeman]

I've only been wrenching on the diesels for a short while, but it seems like quite a few people besides me struggle with v-belt tension.  

On my 1.5, the alt adjuster arm was slotted and so even when I'd tighten the belt, it seems like it would work itself loose in a few hundred miles.  The other problem was that I could never really get a good grip on the alt in order to raise it up and hold it while tensioning.

I began thinking about other VW's I've had (gas models) and most of the later ones (A2's) had an alternator belt tensioner composed of a special toothed bracket and a corresponding bolt/tensioner with the same teeth.  

This is pretty nice in that you simply loosen the 8mm bolt on the inside of the tensioner, then use an adjustable wrench to tension the belt.  The tensioner indexes on the teeth on the pulley, giving you leverage.

This weekend, I had enough and I decided to adapt the same system to my early style arm.   I went to the junkyard and found a spare alt bracket from an A2 gas Jetta (they're also on Audi 4ks's, VW Foxes, etc).  I then ground the weld that held the toothed "rack" off that arm so I could weld it on my diesel bracket.



I then used two adjusters to position the toothed strip on the bracket, then welded it up.



Here's the finished piece:



A touch of paint and here it is installed...



Seems to work pretty well.  It's now way easier to tension the alt belt.  The only difference between this and a factory A2 setup is that the ear on the alternator is not threaded.

Did the later diesels already come with a bracket like this?  It would seem logical for them to incorporate that design.  Come to think of it, early gas engines had the slotted arms, then later went to the "toothed" setup.  

Personally, I've never even seen an A2 diesel in person, so I didn't have any of those parts available to me.  I haven't road tested this yet, but it seems like it should help the situation somewhat.