Dynamo removal

[DavidHill]

A question on dynamo's....when i rev the engine the fan moves in slightly and touches the radiator making a nasty metal on metal rubbing noise.  I have tightened the large nut holding on the fan blade, but realised it is not that, the whole inner part of the dynamo holding the fan is able to move in and out slightly.  I think my best approach is to remove the fan, take the dynamo off the car and tighten the dynamo up before refitting it to the car and refitting the fan.  My question is - is it possible to remove and reattach the dynamo whilst the radiator is still on the car (as i do not want to remove the radiator if i can at all help it!)

Many thanks
David.

[Raahauge]

The answer is that Lancia designed it to be removable but 70 years on things are often not original.
Both the OD of the nut that holds the fan onto it's taper and the ID of the fan itself both have grooves in which should sit a spring clip which engages with both components. There is enough slop in the assembly to allow the nut to tighten the fan but when the nut is undone it is able to pull the fan off the taper, the fan can then be removed and the dynamo can be withdrawn forwards.
If you can remove the nut completely you don't have the clip, if it gets tight then keep going and the fan will come off.
The spring clip is fitted when the nut is inserted into the fan and (as far as I can see) neither the nut nor the clip can later be removed without destroying the fan.
My experience is that the clip is often (usually) missing which makes thing more difficult. I think it would be very difficult to fit the clip in situ.
I have heard that sliding the dynamo forwards sharply, in the manner of a slide hammer works to break the taper though it seems a bit brutal on the rad.
I have the dimensions of the clip (though no spare clips) if needed. Best of luck.
 

[davidwheeler]

I have never seen such a clip and I find the fan comes off without much trouble just by undoing the nut.   I would be interested in seeing the clip and its dimensions.

[Sliding Pillar]

I thought there is a woodruff key on the tapered shaft, but it is a long time since I did any work on an Aprilia.

[DavidHill]

Thanks all for the advice, this morning i removed the nut (the spring clip was missing) and then the fan blade slide off with a bit of gentle screwdriver levering.  There are two big screws that go through the dynamo front to back and they were loose...so I tightened them up and applied a bit of threadlocker and then successfully put the dynamo back in and reattached the fan... problem solved...thank you again!  More noises to investigate now as a shake down the Aprilia - as its finally on the road for the first time in around 30+ years (short trips round the block only currently) and a restoration starting when i bought it in 2013...

[Raahauge]

Here is a picture of the spring clip, a car we had many years ago had the clip as has the recent acquisition but the V groove on the fan was so worn that I had to change it. I cut it in half to extract the clip and was thus able to take a photo. I have had a number of spare fans but none with the captive nut.