924Board.org

tj924 · Posted: Mon Nov 15, 2004 2:44 pm Post subject: Changing the A/C Belt

Any hits/tips for a noobie on changing the A/C belt? Hoping to do this tonight (along with the alternator belt, which I know how to do) but I haven't yet found the adjusting bolt ("banjo bolt???) so I can get the old one off yet. Read the Haynes but haven't yet got my head around where the bits are yet & there are no photos.
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TJ
Silver '82 924 NA 5-Speed Manual

Khal · Posted: Mon Nov 15, 2004 3:09 pm Post subject:

I haven't done an A/C-Alt belt change. I would have thought it'd be pretty straightforward... just like a regular alternator..? With a slide bracket mount where you just loosen the bolt and slide the compressor?
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'80 924 Turbo

tj924 · Posted: Mon Nov 15, 2004 3:25 pm Post subject:

Thats what I expect too. Just have to find it. Nuthin' like learnin' by doin' I guess. Still wouldn't know where the alternator or clutch cable was if I didn't have to fix those recently.
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TJ
Silver '82 924 NA 5-Speed Manual

Smoothie · Posted: Mon Nov 15, 2004 4:15 pm Post subject:

Have a look here - http://pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=bdb3&.dnm=f0ac.jpg&.src=ph
[this is actually a diagram of the earlier mounting parts (from '76 thru some point in '79)]

#4 is the banjo bolt they're talking about and #1 is the nut to loosen. -But from my own experience, loosening that nut can be real tedious, so to quicken the process and allow more clearance to get the belt off-on, I just loosen nut #1 enough to get a little bit of slack, then completely remove bolt #3 and its' washer. That allows complete removal of #'s 1, 2 and 4 (don't disassemble these three from each other - leave the nut and washer on the banjo bolt where they are). Swap belts, replace assembly 1, 2, 4, then bolt #3 and its' washer, then tension-up the new belt by turning nut #1.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

tj924 · Posted: Mon Nov 15, 2004 5:05 pm Post subject:

Awesome, thanks Smoothie. That will help alot.

In that diagram is #14 the double pulley that has both the alternator belt & the A/C belt attached?
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TJ
Silver '82 924 NA 5-Speed Manual

Smoothie · Posted: Mon Nov 15, 2004 5:25 pm Post subject:

No-yeah that does look like a double pulley in the pic, but on my car I believe the double pulley's on the front of the crankshaft - a 13mm belt sits in one of its' grooves and goes to the AC compressor, then there's a 10mm belt in the other groove that wraps around the water pump and alternator pullies.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

tj924 · Posted: Mon Nov 15, 2004 5:39 pm Post subject:

OK thanks. That clarifies it a bit & I think I know where to look now.
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TJ
Silver '82 924 NA 5-Speed Manual

Paul · Posted: Tue Nov 16, 2004 11:30 am Post subject:

I always loosen #3, then use an 3/8 inch air rachet with a deep well socket on #1....

tj924 · Posted: Wed Nov 17, 2004 12:46 am Post subject:

Well, I'm buggered if I can find that banjo bolt anywhere! Does #16 go through the bottom hole of #13 & into the bottom left (looking from the front) bolt hole of the compressor? I only have a bolt going through mine.

Does the banjo bolt (finally figured out what it looks like & why it is called a "banjo bolt") stick out sideways from the compressor? Does it get adjusted from the top of the engine or under the car? Haynes says "The compressor's V-belt adapter is a banjo type of adjuster whose threaded end points toward the thermostat housing". Found the thermostat housing & there is no threaded section of anything pointing toward it.

Perhaps I'm just looking in the wrong spot or I've got an after market unit. There appear to be bolts in the top left front & rear holes that could be hingle points. These bolts need an 8mm allan key (or hex key or whatever they're called) to move them & I've tried & can't move either one. I can't see how, though, there could be any adjustment made in case the belt is too tight or too loose.

Any help would be appreciated.
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TJ
Silver '82 924 NA 5-Speed Manual

Smoothie · Posted: Wed Nov 17, 2004 2:20 am Post subject:

Here's the OE setup on a 931 - http://pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=bdb3&.dnm=979a.jpg&.src=ph
As far as I know, the 924na mounting should be the same, but instead of having the alternator obscuring nut #1 as on a 931, you may have something else in the way.
Bracket #13 attaches directly to the compressor, then #11 attaches to #13 via nut #5 and stud #16 (11 isn't directly attached to the compressor)(and #16 is actually part of #13 according to PET, not part of #11 as that factory manual diagram suggests). The diagram seems to indicate what you're thinking, that bolt 16 goes directly into the lower-left of the compressor, but it actually doesn't.
If you don't have a setup similar to what's shown in the photo, it's probably safe to assume you have an altogether different aftermarket arrangement.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Smoothie · Posted: Wed Nov 17, 2004 2:56 am Post subject:

Here's a diagram of the later mounting parts (from some point in '79-up)- http://pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=bdb3&.dnm=a5e1.jpg&.src=ph
It looks a bit Dr. Seuss-ish, but no I didn't draw it myself - it's an actual PET diagram.

#27 there = #13 from the factory diagram and you can see that stud (#16) is actually part of it.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Smoothie · Posted: Wed Nov 17, 2004 4:19 am Post subject:

Apparently both diagrams are correct, but the factory manual diagram I posted the link to first is for 1976 thru some point in '79. The mounting parts changed some time in '79 and the PET diagram is of the later setup.

In any case the position of the banjo bolt you're concerned with didn't change over the years. It's not visible with the alternator and airbox in place on a 931 and apparently the 924na has some stuff obscuring it as well.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

tj924 · Posted: Wed Nov 17, 2004 9:57 am Post subject:

Thanks for your help Smoothie. I'm assuming the photo must have been taken from above? My mounting looks nothing like that & most of the bolts require an allen key to get off. Can't get a good photo from above as the air box & fuel distributor (the one where the big fuel line goes into & several little lines come out to the injectors) are in the way. My alternator is much closer to the bottom of the engine & slightly to the left (looking from the front) of the top crank pulley wheel (which is, of course, at the top of the engine). Going clockwise, the A/C belt goes from the double (triple?) pulley that holds the alt belt, A/C belt & timing belt, upwards fairly steeply to a pulley that appears to having no motor attached to it, then downward to the compressor then slightly downward back to the 1st pulley.

FWIW, here is a shot of my centre console. The red arrow points to the A/C fan switch. Turn the knob clockwise, press the front of it & a light comes on & cold air comes out (ie the A/C turns on). Does that indicate it may be an after-market A/C?

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TJ
Silver '82 924 NA 5-Speed Manual

Smoothie · Posted: Wed Nov 17, 2004 10:43 am Post subject:

Yes, that pic was shot from above.
931 alternators are located top-front-center in the engine compartment. As far as I know, 924na alt's are below the exhaust manifold, approximately where the turbos are located on 931's.. I'm a bit confused by your term "top crank pulley wheel". There's only one crank pulley and it's attached to the front of the crankshaft near the bottom of the engine. I have to assume you mean the cam sprocket?

If the AC was factory installed, the control knob would be where your clock is like this - http://pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=a174&.dnm=3e76.jpg&.src=ph
What you have may have been requested by the first owner before or as the car was purchased - and then installed by the Porsche dealer. -If so, what would that be... not factory, but not really aftermarket either. Obviously call it dealer-installed.

(If that's what it is.)(and if the compressor mount is different from what's shown in those diagrams and picture, sorry then, I have no clue as to how it's adjusted)
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

numbbers · Posted: Wed Nov 17, 2004 11:09 am Post subject:

My guess is, you have an after market AC.
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1980 924 Turbo