AC/Alt Belt Tension

[spacecad3t]

This question has been asked to death Im sure. I googled it and got a wide range of responses...

• Use the special tool...

• ~5mm of deflection (Old forums)

• 2mm deflection (NC944er youtube)

• 1/8 to 1/4 twist (Old forums)

• "Wicked" tight...

Looking for the Carpokes opinion here. I just changed my alternator and put on a new belt and tensioner rod, Im somewhere between 2-5mm (hard to tell, seems like 5mm) or 1/4 twist... Dont want to stress any bearings, but its definitely wicked tight...

Crap photo of the twist method.

IMG_2837.jpeg (2.42 MiB) Viewed 628 times

[Tom]

The factory tension level is crazy tight. I've tried it with the official tension tool and It just seems excessively tight to me. Here's mine right now. This is probably 3 or 4 turns of the turnbuckle below the factory spec -- maybe an 8 or 9 on the tool. Been doing it this way for decades with no squeal or other apparent problems.

[spacecad3t]

The factory tension level is crazy tight. I've tried it with the official tension tool and It just seems excessively tight to me. Here's mine right now. This is probably 3 or 4 turns of the turnbuckle below the factory spec -- maybe an 8 or 9 on the tool. Been doing it this way for decades with no squeal or other apparent problems.

@Tom How did I know it would be you, and damn, a youtube video that didnt come up when I searched Google. You are on top of it!

Your twist looks similar to mine... maybe even less twist then I have going on... so I guess I'll just leave it as I have it for now.

[Tom]

The factory tension level is crazy tight. I've tried it with the official tension tool and It just seems excessively tight to me. Here's mine right now. This is probably 3 or 4 turns of the turnbuckle below the factory spec -- maybe an 8 or 9 on the tool. Been doing it this way for decades with no squeal or other apparent problems.

@Tom How did I know it would be you, and damn, a youtube video that didnt come up when I searched Google. You are on top of it!

Your twist looks similar to mine... maybe even less twist then I have going on... so I guess I'll just leave it as I have it for now.

My car was on the lift, so that's a bespoke video just for you. Youtube just makes it easy to upload and share while standing under the car.

[Tom]

p.s., give it a thumbs up or comment to bump its views -- trying to get to the min hours watched to start making a dollar a month

[spacecad3t]

p.s., give it a thumbs up or comment to bump its views -- trying to get to the min hours watched to start making a dollar a month

Done! Thanks again.

[spacecad3t]

@Tom Sorry for the low res video, but curious what you think. Didn't notice this before my alternator/belt change. Is my belt too loose/tight? Or is the AC clutch/bearing going out? I wondered if the PO had loosened the belt on purpose to reduce this squealing.

[Tom]

@Tom Sorry for the low res video, but curious what you think. Didn't notice this before my alternator/belt change. Is my belt too loose/tight? Or is the AC clutch/bearing going out? I wondered if the PO had loosened the belt on purpose to reduce this squealing.

Yeah, I dunno, that sounds more like a metal-on-metal chirp to me than traditional belt squeal from a loose belt -- pulley bearing or a/c clutch maybe. I'd spray a little water mist on the belt and see if the sound goes away. If so, then you might play with the tension and/or get a new belt and cross your fingers. Assuming it keeps chirping instead, I'd put a mechanics stethoscope near the various pulleys (safely) to see where it's coming from.

[PSU_Crash]

I get a squeal from the AC belt at cold start pretty often. I thought my compressor might be on it's way. My belt is no where near that tight. I guess the Porsche engineers know best. Time to tighten mine a bit more