Alternator Belt

[Andrew P.]

Hello,

1971
350 270hp
4 spd
With A/C and PS

Does anyone know where I could get a reproduction alternator belt?

Every source I have tried said they are on back-order. I've order one from Corvette Central back in Jan and they still have no idea when/if they are coming.

Will any other belt for a differnet application work?

Any suggestions, leads would be greatly appreciated.

Thanks,
Andrew Papanicolaou (48361)

[Jack H.]

Re: Alternator Belt

You've got a couple of choices. Go with a cloth wrapped reproduction of the factory original: 3891946 (3/8 x 54 inches) or use the GM service replacement belt that's die-cut: 9433766 (7/16 x 54.5 inches).

In my opinion, the later die cut belts are MUCH more durable, but you will take originality point deduction(s) for their difference in Configuration. The die cut service replacement belts used to be plentiful and cost effective from your local Chevy dealer.

But, in recent years GM has gotten out of the belt business. So, when you ask for the part the counter man is likely to tell you it's discontinued... The last time I needed one for my car (same config as yours '71 SB with A/C and PS), I asked the parts guy to run 'locator' and he found more than one Chevy dealer in the US with old stock still on the shelf!

I phoned the dealer nearest to me and had the belt in two days via USPS priority mail flat rate mailer envelope.

BTW the difference in sizes deals with the width of the belt. A wider belt will ride higher in the pulley grooves and therefore need to be longer to compensate. The 7/16" width corresponds to the standard '440' belt category.

Last, now that you know the modern equivalent is .440 x 54.5, you can buy/install any 3rd party brand belt to get you up and running with the knowledge it won't have GM identifying 'marks' on it...

[Kenneth H.]

Re: Alternator Belt

Jack, have you tried Quanta Products. I just purchased an alternator belt for my 70 and it looks great. However, in previous posts, some members advised that their belts are more for judging than for everyday driving. Other members have disagreed and stated that the belts are fine for driving. When I spoke to Quanta the said that correct alignment was critical and that the belt should be readjusted after about 100 miles of driving and I followed these instructions, the belt would be fine.

[Dale S.]

Re: Alternator Belt

I dont know why a wrapped belt would not work fine. That was all we sold for years (Gates). Yes, it has to be tightened after a few miles. If it does not work maybe it is made of different materials than the old belts. Dale

[Jack H.]

Re: Alternator Belt

To my knowledge, Quanta, is the only source for cloth wrapped reproduction belts (regardless of whose catalog you buy from). My experience comes from having installed a set of three on my '71 SB A/C PS driver car about the second year they were available.

Two out of my three belts broke within roughly 2000 miles of use. Others in this area who'd bought/installed those belts and actually DROVE their cars had similar experiences.

When I replaced the reproduction belts with GM service replacement, die cut, belts my problems went away. I've logged +50K miles on since...

So, maybe Quanta had quality control/formulation problem(s) with their initial production that's been fixed now. But, I haven't heard/read any white paper admission(s) to this effect...

So, that's why I have the mind set that I do: the reproduction belts are fine for a trailer queen that sees little/no actual use...

[Dale S.]

Re: Alternator Belt

I agree with your position, having had your experience. You would think Quanta would want to clear that up. I will take a deduction for my Gates cut belts until I hear of a satisfied customer. Dale

[Andrew P.]

Re: Alternator Belt

Thanks for all the information and advice.

My car still has the original PS and AC belts, and both in great shape.

Still no one has a reproduction belt at this time for this application.


Thanks once again,
Andrew Papanicolaou