Morris Minor Owners Club

Evening all. Simple question from the stupid questions dept. Can a fan belt slip without making a noise? Can it slip quietly enough not to be noticed, but still affect charging? I have an alternator fitted, not a dynamo.
Cheers N

simple answer yes

Just fit a new one - 825 is what you need. Tighten the one you have and it will snap....

As bmc says above fit a new belt.
The alternator provides more resistance to turning when charging - so the fan belt needs to be much tighter than if a dynamo was fitted.
That is why you can hear the alternator drive belt fitted to many modern cars squealing immediately after starting especially on a cold morning with all the electrics brought into use as the alternator goes to max charge.
The majority of modern cars fitted with alternators have multi-grove drive belts fitted to increase the contact area between belt and pulley so reducing the possibility of belt slip.
The biggest problem with having the fan belt too tight on an 'A' Series is that it increases the possibility of causing the water pump bearings to fail - so the belt should be tight but not too tight.
A shake of talcum powder on the belt and pulleys usually cures any slippage providing that the belt is in good condition and is correctly tightened.
Phil

Make sure the three pulleys and the belt are free from oil - that can cause slippage......

And in perfect alignment,