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How Much Do New Rubber V Belt Stretch?


Today to continue the day before yesterday's topic. The […]

Today to continue the day before yesterday's topic. The alternator belt was flopping around and squealing, so I tightened it up. Now the belts are once again chirping at me (only at idle). I believe its probably the Compressor/water pump Rubber V Belt is loose.

Should I expect to readjust a standard V-belt a few times or should I be checking the pulley alignment?

V-belt should NOT stretch as much as me describe. V-belts can wear-in and loosen a bit over many miles but they don't usually require re-tightening after a few days. I think it has a problem.

Fantastic. I'll have to take a look at the pulleys then. Maybe it's an alignment and/or pulley issue.

Different story here. I snug up new v-belts a touch more so I don't have to go back and re-tighten them. I can go overboard and ruin bearings that way but I never had a problem.

So I just went out a retightened everything properly. However I still have the chirp/squeal. As soon as I give it some gas, it goes away. From poking around with a stethoscope I determined its originating from main pulley/water pump area.

The problem is rarely the pulley itself. If it is not the belt, and you are using the correct belt and didn't do anything to change the belt alignment, it would usually be something wrong, like a bad bearing, on one of the accessories or tensioners used by that belt.

One thing I've learned over the years as a DIY, be sure to carefully compare the old belt to the new before replacing belts. They should be the same length, same width, same cross section shape, and, if grooved, have the same number of groves.

I just had the vacuum pump out, but it seems localized and not something resonating. The timing belt tensioner is a maybe, I sure hope not though.

That's all! I hope my advice will help you.