flexbert

The other night as I was aggressively pulling away from a stop (and my wife always wonders why I come back from a drive smiling), I hear a high pitched squeal from the rear. Hmmmmm. Didn't hear it again the remainder of the drive home but it sounded an awful lot like a fan belt squeal. When I get home, pop the engine cover, engine running and rev it slowly - no sound. Rev it quickly and around 2500-3000 rpm, there is the squeal again. I moved around to the engine compartment and revved the throttle from there and I noticed the fan belt seemed to stretch as I revved the engine quickly. My conclusion - loose fan belt. Shut the engine off and there is about a 0.5" to 0.75" deflection - check Bentley and it says it should be about 0.2".

This is my first Porsche (86 911 coupe) and I've only had it about a year and have not really had to do much in the way of maintenance since I got the car. So I go back to the Bentley to verify how to tighten the belt - remove pulley and move shims from between the pulley halves to outside the pulley to tighten. I note the direction to make sure I use all 6 shims in total when replacing the pulley.

Porsche pulley holding tool comes with tool kit in 911 to hold pulley when loosening/tightening the nut to remove/adjust the belt.

When one doesn't have the toolkit that is a challenge . Adapt and overcome - tried to find a screw driver with the correct diameter to fit snugly into the hole on the pulley to hold it in place while removing the nut - no go. Finally used some cable, similar to a bicycle brake cable except larger diameter (= stronger) that I fed through both holes on the pulley, making sure it went around the nut and then around the A/C compressor mounting bracket. I secured the cable back on itself with a locking clamp. Of course, in the process of securing the cable I dropped one of the 5/16" nuts - twice After searching around (I heard it drop on metal), both times it ended up underneath the crank pulley: small space + big hands = telescoping magnet to finally retrieve the nut, both times.

I finally got the nut off of the pulley and all 6 shims were between the pulley halves. There was a new belt on the car when I purchased it a year and ~5000 miles ago, so that made sense to me. Based on how much I could deflect the belt by hand, I decided to try moving two shims to outside the pulley halves for the first go around. I made sure all 6 shims were on the shaft - 4 inside and 2 outside the pulley halves, secured the lock washer and nut and torqued (30 ft-lb) as per Bentley. This seems to have done the trick.

Observations:
1. Must acquire a tool kit (preferred) or at least the essential components of the tool kit
2. Be careful with small nuts - they manage to find their way to the most inconvenient places when dropped
3. I continue to be impressed with the engineering that went into these cars and the quality of the hardware etc that went into their assembly.

--flexbert

theiceman

I think there is a member here that might make the tool you are looking for.
Good work on ur first repair

wildcat077

Do a search on the Pelican classifieds,there are lots of people with various assorted tools who will be able to sell you what you need for your tool kit.I was missing a lot of stuff from mine when i purchased my car,now it's pretty much complete !

Cheers !
Phil

SiberianDVM

My $5 telescoping magnet is the most valuable tool in the toolbox. The only time it's failed me was when I was installing a Rennline truss mount front strut brace, which uses several aluminum spacers.

You guessed it: several of them slipped away from my fumble fingers and managed to find the most inconvenient spot: under the smugglers box blower fan (the lid has been removed). I had to disassemble the whole darn thing.

Anyway, good job on the belt. I replaced mine last month as the old one was loose and looked slippery and cracked. I was lucky my Targa came with the full tool kit.

porsche0nut

Good writeup and nicely done - I think doing our own work on these cars greatly enhances the overall ownership experience!

Make sure your oil cap is always on when working around the engine bay.... I had quite the scare one day when I dropped a nut and thought it had fallen into the open oil filler tube! (Thankfully, it didn't.)

Good call on the magnet Siberian... I need to pick up one of those.

1986 Targa

I made my own.....

time907356

Well, I thought I'd just hi-jack this thread, since it's what I was going to title mine. To make the short story long, we got the mystical red charging light on our 87 Carrera, so I grabbed the voltmeter and went to work. Ended up buying a rebuilt rhone alternator after seeing the idle voltage dropped to 12V. Still, the red light. So replaced the battery, and still the red light.
The latest was to replace the belt, as the deflection was ~1/2" rather than the <1/4" recommended. The light is out for now, and the belt vibration at idle is MUCH less, and deflection is minimal. However, the problem is that I have NO shims between the sheave halves with a new 10mm x 710mm belt! The belt is sure to stretch, so how does one adjust tension without shims??

theiceman

okay a couple of points ...

so you replaced the alternator and put the old belt back ? thats funny right there ..

thats like going in the shower and putting your old underwear back on ..

so anyways .. i would think that if you have a new belt and 0 shims then you have the wrong belt. I have heard of some belts requiring different number of shims obviously. Either that or you have the wrong alternator but i just cant see that . i also cant see mounting it closer than designed as it is impossible i would think.

As a side note i think an alternator with a half inch deflection should charge just fine under normal circumstances. Now that the light is out what is your alternator puttig out at idle and 2,000 rpm ? .

BTW my belts are all 725 by 10 conti with no issues.

time907356

Well, it' my underwear!
The belt looked in good shape before I did the alternator; no cuts, missing teeth, skid marks(!). I didn't think anything of it until I removed it to replace the alternator. I did notice the vibration in the belt though and thought it excessive. When the alternator/battery didn't fix it, only then did I try a new belt, assuming it was stretched. I fully expected to add those shims in! Again, it's a little tighter, but no room for stretch...know where I can find a 705mm?
I haven't checked the voltage again, but will tonight. It checked ok (12.5-13.7) when I replaced the battery, but that was 'cold', in the garage. When the belt heats up, it could have been stretching, as it was usually after a short drive, at least, that the light came back on.

Peter Zimmermann

FWIW;
time's belt is an after market belt, a real Porsche belt should be 9.5x710, not 10x710. ice's belt, on the other hand, should be a 725, based on the age of the car. BTW; Goodyear makes the best 710 - it's available at the P-car dealer.

time907356

Seems like the 10mm should be even tighter than a 9mm? Makes my situation all the more curious???

theiceman

Just what I was thinking too.. This is weird. Too bad you didnt measure the voltage after the light came back on on it might have told us something.

But for what it's worth i have had the same belt for about 5 years of summer driving and it hasn't stretched at all. So at least you can be driving around while thinking about it.

Peter Zimmermann

You would think that the 10mm belt would fit tighter, but the belt maker makes a difference. We used to buy 9.5 x 710 Goodyear belts by the dozen, they're very well made and so consistent that we were able to install them with 5 shims between the pulley halves, and one under the clamping nut. Never had a problem, never used 10x710s.

time907356

Things get weirder...The voltage check's out at 12.5V with the car sitting. After starting, it bumped up to 13.25, and goes to 13.5 with ~2k rpms. Then, while I was checking it, and cycling the revs, all of a sudden its back to 12.5V! Rev's didn't affect this reading. So, we shut it off, rechecked it at rest; 12.5V. Started it back up; 12.5V. Reved the motor a few times, and 12.5V. Then, while running at idle, all of a sudden, 13.25V shows back up, without provocation??
So, what loose wire is causing this? The positive terminal has about 4 wires connected; if there's one directly to the alternator, that might be the culprit. Any suggestions?

theiceman

well i think we are definitely getting closer to the route of your problem . As i suspected it has nothing to do with your fan belt.. What you are measuring is battery voltage at 12.5 .. if your alternator kicks out and your battery drops below 12 then that light is coming back on . I would say you possibly have a bad connection or ground .. or hopefully not this but a bad regulator inside your alternator.

the 13.25 and 13.5 are doing exactly what they are suppose to so when it is working it is working fine.

i would check all your grounds including the one underneath at the transmission crossmember mount, Also maybe replace the bulb for your alternator light in the instrument panel .

This one may be challenging ..