How much tension in A/C & alternator belts?

[Stainless]

How do I know how much tension should be in the belts? I drove the car 1600 miles a couple of months ago and hardly at all since, and while I was showing the car to a friend recently, he pointed out to me that the belts were extremely loose. They both have a few inches of play in them when pulled and/or pushed.

I am new the the car and know that the belts were replaced in the past 12 months by the previous owner. I just don't think that they're supposed to be that loose and couldn't find any info in my parts or shop manuals regarding the tension. On a side note, the engine is running great.

[DeLorean03]

Word of advice: if they don't own a DeLorean - generally - do NOT listen to anyone tell you about your car. I remember a shop telling me (who told me that they could and knew how to work on DeLoreans) that there should not be "so many hoses" in the aluminum coolant pipes. Yeah....

Anyways, the rule I follow: don't overtighten. If you can push the belt down with your fingers and it gives a "little", that's fine. It's hard to give a discrete value on something like belt tension; there really is no "one right answer" to the question. If you want a "numeric" answer, I would say any more play than half an inch (being able to push the belt down more than half an inch with your fingers) is an indicator to tighten the belt down some more.

Overtightening = you can damage a lot more than just the belt. Be careful and don't overdo it.

[Stainless]

Sounds good. Thanks for your help. It definitely has more slack than a half an inch. I'll have to tighten it down moderately before she's I get her back on the road. Thanks.

[David T]

Tight enough so they don't slip and then just a tiny bit more.
David Teitelbaum

[Ozzie]

Agree. The setting that's worked for me is about a 1/2 inch deflection from pushing with my finger on the longest span of unsupported belt.

EDIT: This is the rule of thumb that I use on D for the last 5 years. As written above, I take this (visual) measurement on the longest span of unsupported belt for each belt. This is how I set my belts and it has worked great. Once you get your belts the way you like them and prove them out, try to deflect them with this technique, and as long as you are consistent in the way you take future measurements, you'll have a good guideline to go by.

[Bitsyncmaster]

Using a standard deflection would not be the same for all cars. It depends on the distance between the two pulleys where the belt is deflected.

I have a good feel for how tight because I have worked on cars all my life. But for those that don't know just set it on the loose side. Then if it squeal's or flops around when running to much give it a little more tension.

If you put the AC on, that should also load your alternator and you should hear if either belt is to loose.

[Ozzie]

Using a standard deflection would not be the same for all cars. It depends on the distance between the two pulleys where the belt is deflected.

I have a good feel for how tight because I have worked on cars all my life. But for those that don't know just set it on the loose side. Then if it squeal's or flops around when running to much give it a little more tension.

If you put the AC on, that should also load your alternator and you should hear if either belt is to loose.

OK, I'll edit my post for what I probably wasn't clear enough on.

[Bitsyncmaster]

OK, I'll edit my post for what I probably wasn't clear enough on.

Your post is very clear. I just meant there is no standard that can be used adjusting every belt. One car may be correct with the 1/2 inch but another car may be one inch.

Sorry if you took my reply wrong.

[Ozzie]

....Sorry if you took my reply wrong.

No, no. Was not taken wrong, I should write the same to you.

I just wanted to make sure that I was clear in what I wrote. IF I do respond during the day to DMCTalk forum posts, they are usually very hurried with all other things taking place - so I appreciate if anyone lets me know if I wasn't clear enough so that the correct and clear information is put out there -> which is what I thought you were doing.

[Bitsyncmaster]

IF I do respond during the day to DMCTalk forum posts, they are usually very hurried with all other things taking place -

I do the same. Especially at quiting time or if someone wants to interrupt my reply at work and at home (The wife may say.....WE HAVE TO LEAVE NOW).

Then I think about it and think, "I worded that wrong".