Alternator question

[Acollin]

Series V 1966

Probably for as long as I've owned my car, at start up, I would hear the telltale rattle of what I thought was an alternator going bad. Once the car warmed up the sound would go away and charging was not a problem. I assumed the alternator would eventually fail and I would replace it.

I read the strings-- no Lucas replacements-- how to refit an hitachi , etc and thought , this year, I should do something about it.

Well, I found the belt to be loose--- tightened it to a good adjustment and the rattle disappeared.

Does this mean I simply needed to adjust my belt or that with the tighter belt I am masking the rattle as there is now more tension on the soon to fail bearings and I will soon need to replace my alternator. My belt is not over tight now-- but simply a good adjustment.

As long as the " rocks in the tin can" sound is quieted and the charging system is working, I am a happy camper.

Please advise

I guess this is my season for electrical questions.

Be well all
Andrew

 

[mikephillips]

Try removing the belt and spinning the pulley by hand. If you can feel anything like a grinding then you have bearing issue since it ought to spin freely and smoothly. I would guess you'll find some amount of that since a loose belt doesn't normally result in those type noises, but instead would squeal when hitting the gas or slight smells from the belt slipping or fluctuating charging.

 

[Ken Ellis]

And while it's off, check for play in the shaft, too.

 

[65beam]

question

If your car is a series 5 and has the original alternator there is another problem that can cause noise. The fan blades and the pulley are a two piece unit. The shaft has a key pressed in it in the same manner as the rear axle. The fan is sheet metal and has a slot that sets over the key and the pulley pushes on to hold the fan in place using the large nut. Being sheet metal I have found the slot or notch for lack of better words wears and the fan can hit the alternator housing. I went as far as cutting a new notch in the fan housing many years ago.

 

[Jimjordan2]

What??????

 

[Jimjordan2]

Oh, I got it, the Fan blade of the alternator. All right I'm with ya. Whew.

 

[65beam]

question

THINK ALTERNATOR! Many years ago we had one of the alternator fans get so loose that it was scoring the housing where it hit. That was a long 125 miles home.

 

[Acollin]

There is a great picture in the wsm that should go along with 65 beams point.
Sections N ---- p23

I will Investigate tomorrow.

Questions:

If the woodruff key is broken or missing, would simply tightening the fan belt stop the rattling sound of the alternator fan blade rattling?

If the woodruff is gone/ broken, how difficult would it be to simply replace the woodruff key assuming the slot for the key is still in good shape?

Thanks --- all is quiet in the engine bay for now--- the last 50 miles or so!!!!
Andrew

 

[DanR]

I would say if broken, tightening could solve the noise, atleast temporarily.

If the key is missing, tightening could hold the pulley in place for a while but eventually it would or should start slipping.

My 20 mills worth,

DanR