Thread: Alternator Pulleys?

I've just bought a new alternator for my Disco ('94 300tdi) and put the old and new alternators side-by-side. The new alternator has a much smaller pulley on it.
The tacho seems to read correctly so I'm inclined to use the larger pulley off the old alternator on the new one. Can anyone see any reason why the smaller one should be used? Is the smaller one used on later models? (mine is the first of the 300tdis)
It's got me thinking because I bought a replacement belt a couple of years ago and it was too short to fit. Seeing this smaller pulley makes me think that this may have been used on the later 300tdi.



Thanks in advance

Paul

Originally Posted by hook

Yep,
my 98 300 TDi D1 has the small pully.
and it will spin faster.

Yes it will spin faster on mine, but yours should be doing the same RPM as mine, otherwise the tacho would be inaccurate. This must mean that your harmonic balancer must also be a bit smaller.

The only way that I can see that the smaller pulley can be used and allow the alternator to spin faster is if the tacho is calibrated differently in the later models. This is entirely possible but is it true??

Can anyone shed any light on this one?