Loose Fan Belt - Need some help | 356 Speedster, 550 Spyder, Replica, Automotive Community

Distefano

Allright, don't laugh. I know this is basic, but we all have to learn sometime, and I'm trying to avoid newbie mistakes.

I had my car in the shop last week, and today I noticed that when they put my fan belt back on, it was twisted - the teeth were correct on the bottom wheel, but were sticking up on the top. I took it apart to correct it, but when I twisted the belt back, it was way too loose - see pix.

Muir's book says to remove the washers to tighten it back up, but after tinkering with it, I don't see where that will help. I'm probably overlooking the obvious, but I need to get this belt back on asap. Thanks in advance for the help.

Brian

6/10/063:46 PM

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Distefano

6/10/063:46 PM

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Former Member

brian, the washers/spacers seperate the two halfs of the pulley. the more washers between
the two halfs, the shorter the distance from the furthest point of the bottom pulley to the
furthest point on the gen. pulley. Fewer spacers/washers brings the two halfs closer,
increasing the diameter of the pulley and the distance the belt has to travel around.
Think of it as a "roundabout" or traffic circle. Your belt (the car) has to follow the road
if your were able to cut a smaller diameter path thru the circle your travel (car/belt) would
be less. Follow the outside of the cirlcle=longer.

6/10/063:58 PM

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Distefano

Thanks Bruce. I watched the Bug Me segment on this and it really helped. Now I understand how it works on paper, but it's not working out so well on the car. I have it all back together, but the belt still squeals every time I throttle it. It has about a 1/2 inch give (recommended), but the belt is still visibly wobbly when the engine is running. I think it might be ruined from being twisted.

6/10/064:58 PM

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Former Member

If the tension is correct then maybe oily hands are to blame. In the "old days" they
sold "belt dressing" I think it was just some sort of thinner or other to make sure the gripping surface was clean.

6/10/066:03 PM

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Distefano

I tightened it up some more, and when I started the engine, it made a serious rattling sound (almost like a diesel engine), and I cut it off immediately. There is no way this should be this difficult. Squeals I can handle, but now that it's rattling I think I need to bring it back to the shop to let them correct their error. Any ideas?

6/10/066:33 PM

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BOKURI

Also try checking the alignment of the belt. Stand on the side of the car and look along the belt lining up the crank pulley and the alternator pulley. Maybe they are not aligned. They sell spacer for this.

6/10/066:34 PM

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Theron Site Administrator

I haven't seen belt dressing in a while, but toothpaste works as a good alternative. It cleans the pulley, gets sticky when warmed and puts off a nice minty smell.
-=theron

6/10/068:59 PM

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Nolan-Tennessee

That rattling sound might be your fan hitting inside the doghouse shroud. Try starting the engine with the belt off and see if the sound goes away. If the sound is gone, check to see if your alternator is mounted correctly and the screws holding the fanplate are tight behind the alternator. If your fan belt is too tight it can actually pull the alternator down(it may be pulling the alternator shaft down too hard and wearing down its bearings) and cause the fan to hit the shroud. I used to used WD-40 to lube my fanbelt (don't know if it was good for the belt or not but it cut down the squeaking).

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6/11/066:38 AM

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Former Member

Run! Don't walk back to the shop and have them correct it. It sucks paying for something
and not being able to trust their work.

6/11/069:54 AM

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Distefano

Thanks for the help guys - I finally got it running right. Nolan, you were right. Once I loosened it up a bit and put a new belt on, it straightened up.

Brian

6/12/0612:40 PM

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Nolan-Tennessee

Glad to help, I learned a few tricks from my late neighbor that had a '38 chevy two door with Corvette running gear. He was instrumental in helping build my Spyder.