How tight does the alternator belt need to be?

[Quinten]

I've replaced the alternator belt and tightened it so that you can just about do a 1/4 turn on the longest side.  Is that tight enough or too tight?  I've seen a measuring method using a ruler and pulling it away from it (no more than 1/2 inch stretch), but I do not have the space to try that out  

[Mighty Mart]

Sounds about right, but wouldn't have it any tighter tbh.

Mart.

[CraigHew]

Old school method was to grab the belt in the middle of the longest length and wiggle side to side.

One inch movement (ie half and inch each way) was the target.

[si_salisbury]

It sound about right, you might need to re-adjust the belt after a few runs as the belt could stretch. I have heard of people over tighten the belt to allow for that but if it don’t stretch then your over stressing the bearing in thing like the alternator.

[Dave Eastwood (Gadgetman) - Club Chairman]

34 minutes ago, si_salisbury said:

It sound about right, you might need to re-adjust the belt after a few runs as the belt could stretch. I have heard of people over tighten the belt to allow for that but if it don’t stretch then your over stressing the bearing in thing like the alternator.

Yeah, much better just to check when you do your regular underbonnet checks.

 

[Quinten]

Cheers guys.  I slackened it off ever so slightly as it felt it was just a bit too tight.  Now everything is back together again I'll include the tension into the regular spanner check