Scuba Steve

update
The problem is definitely related to either the alternator or A/C. The noise didn't change when the A/C was on so that means that it can't be the A/C clutch? The alternator turns smoothly but I can hear it 'tick' a little when I spin it.

I turned on my car today and noticed a different noise. Every 1-3 seconds it will chirp, usually once or twice but sometimes a little more. I'm guessing that one of the rollers is going out. All belts were replaced about 3 months ago and I've driven just over 1,000 miles since then. They haven't been retensioned since they were installed.

Is this noise consistent with roller or idler pulley failure? Maybe I'll get lucky and it'll just be the balance shaft idler being out of adjustment; I haven't checked anything out but I'm getting ready to.

Techno Duck

Chirp could be a belt slipping (alternator or powersteering). Likley the alternator. Does the chip become more consistant with heavy electrical load (rear defroster, headlights)? Check the tension of the alternator belt, should be at about 85 pounds or 5mm of deflection (press on it with about half force with one finger).

My 924S made a chirping sound also, tightened the extremley loose alternator belt and it went away. But we may be talking abotu different chirps .

Scuba Steve

I'll keep that in mind for when I go down there. It doesn't change in pitch when I rev the engine and turning on the A/C doesn't change anything either. The alternator light hasn't turned on.

Scuba Steve

Ok, it got stranger now. The a/c belt was a little loose (60lbs) so I tightened it. Turned the car back on and it still chirps like before. Since the hood was open I decided to try and track it down, and it doesn't sound like it's coming from the belts. The sound seems to be coming from the drivers side, rear of the engine. Maybe this is an echo or something? I can't think of any reason for there to be an occasional chirp from there. Maybe something went down the flywheel inspection hole? Now I'm starting to get worried.

Scuba Steve

Ok, back again. Upon closer inspection it does kind of sound like the chirping is coming from the alternator. Makes sense - it's stock. I don't know anything about this kind of failure, I've only replaced alternators when they quit charging. Anybody else had alternator bearings go bad?

blackcube

I have on my 83. They went bad while I was on a long road trip and seized just as I pulled into the parking lot of my office building. I had it towed to Zim's for a rebuilt alternator install. I was worried it was the water pump but didn't have time to try and fix it myself. It started out as a chirp like noise.

Scuba Steve

I've been looking around on the internet to try and source the bearings without much luck. Anybody know the part number? I've searched around on the forum for awhile but haven't been able to come up with what parts are needed and how much they might run.

theedge

Prolly easier to get a fully rebuilt alternator. That gets you all the other wear and tear items replaced, like the brushes, etc.

dmsog

I am a rebuilder by profession and I can supply you with anything you need.
Not to be a killjoy, but many of these units come apart hard and it's very easy to break the front housing during dissassembly without heat, a quality hand impact, a bearing splitter and a good puller. Some come apart easily, but not all.
If you decide to tackle this job, you'll need a 303 and a 202 bearing, preferably rubber sealed, not metal shielded.

Doug

Luis de Prat

The alternator failed on my 83 as well. It started out with noisy bearings and after a few days the alternator went out with a bang. You should replace it before it leaves you stranded.

Have yours rebuilt by dmsog or buy a rebuilt unit for your car. Most of the Rennlist sponsor vendors carry these.

Scuba Steve

I got lucky here - the person that sits next to my desk at work is friends with someone that's been rebuilding these things for awhile now. He says that he can get the job done so long as I supply the bearings and brushes. Anybody have the part number for the brushes?

If for some reason the person here can't get it done I probably won't be cracking it open myself. I haven't used a lot of force on the housing, but it looks like the cast metal would be prone to breakage. It's good to know that there's another option to getting a whole new unit - they run 3-4x what the one on my truck costs and I've already hit my car budget for the month!