[Col Tigwell]

With my limited experience, short fan belt life is often associated with either excess pully wear, or the belt is not the correct cross section for the pully grooves.

Many think that so long as the belt is in the grooves all is well.

This is not so, the outside of the belt, (the place where normally the belt markings are placed) must ride above the pulley flance. The distance should be about one to two MM.

If this does happen, then the belt tends to overheat, which causes the strong part of the belt, (which again is the outside) to ride down in the groove, which again places pressure on the belt.

I would try temp. fitting another belt, and observe if all belt protrusions are the same. If they are not then it could mean that one or more of the pulleys have worn too bad for use.

If they are all below the pulley groove, it means you will have to go to a wider belt. Belts come in different grrove widths, and you should be able to go up in size at a good belt stockist. My experience shows that cheaper belts are not worth buying, and you need to seek Dayco or Gates belts for maximum life.

Taking a pulley off the truck, when you do your selection, so you can trial and check the belt riding in the groove, will assist you in your venture.

Please ensure the belt btension is correct, and also check that there is no drag coming from the generator or water pump, if their bearings are getting tired, they too could be creating extra drag, which will make the belt overheat too.

I hope I have given clear enough points for you to look at.

Regards

Col Tigwell