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Behind the pulley

The Wonderbus Tales continue.

The bus is running pretty okay. I invite my wife to drive it to the gym this morning. 15 minutes after she leaves she calls - the Gen and Oil lamp both came on. She had been cruising at 40 MPH, and stopped at light. The idle was high when the lights came on. "Pull over as soon as you can," I said, knowing that the day's plans had changed.

I drove over and found her parked in the closest spot alongside the road, about 1/2 mile from the traffic light where she had noticed the indications of trouble. She had opened the engine compartment and found that the alternator belt had come apart. (I do have an alternator, not a generator on my 1776 engine.) There was smoke and the engine was hot. I have a Berg temperature dipstick which lights the Oil lamp with overtemp.

This all suggests that the belt came apart, the cooling stopped, the engine got hot, the dipstick lit the lamp and around the same time the Gen lamp came on because . . . well, you get the picture.

Before installing a new belt, I noticed that the pulley was scraping on the front of the alternator. (Wish I could say that I had my 17mm wrench with me but I had left it at home and had to drive back to get it.)

The pulley seemed to have zero clearance between its rim and the alternator, and it wobbled. The scraping got worse when the pulley nut was installed and tightened.

With a little pushing and tugging I got pulley front half off (front is FRONT). I had never pulled one before and nearly lost the little half-moon key. The front on the alternator was pretty badly scraped. It's never scraped before and the scrapes were bright-metal shiny.

I could not see what is supposed the keep the pulley properly spaced away from the alternator's face.

There is a large washer, kind of dished, between the pulley and the alternator. It appeared that by flipping the washer over, the pulley would get spaced further away from the face of the alternator. And that's how I tried to use it, but either way, it would not stay in place concentrically when I tried putting the pulley front half on. The hole in the washer was quite a bit larger than then alternator shaft so it would not center. It seemed to be responsible for the wobble.

I centered the washer on the pulley by eye and used DUCT TAPE -- little strips -- to fix it in place. By this method I was able to get the pulley re-mounted without any wobble and spaced far enough to avoid any scraping.

Questions for the Wise Men O' The Group:

  1. How in the world did the shredding of the belt cause the pulley to start scraping against the alternator?

  1. The washer (or spacer) that goes between the pulley front half (front is FRONT) and the alternator -- is it supposed to be dished or flat? Is there a preferred mounting direction? Why is the hole in the washer so much larger than the alternator shaft that the washer hangs down and causes the pulley to wobble (presses against the ribs on one side). Or is this some bogus bunch of crap hardware that is found only on the Wonderbus?

  2. Is there a drawing someplace (can't find in Bentleys Bus Book) of all the bits that mount to the alternator shaft? Spacers, shims, pulley halves, half-moon key, nut, etc.?

I am a bit disgruntled right now. It would be great to say that my amateur roadside repair got the Wonderbus running, but it won't start. Starter turns over the engine -- but it does not seem to be too enthusiastic about starting. Had it trailered back to the house. Will poke and prod tomorrow. I sure hope the engine is not baked.

Reply to
Mike Rocket J. Squirrel Elliot
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Oh fer cryin out loud.

It's TOAST, DUDE! Start all over. You ended up on Boardwalk with a hotel. Don't pass GO.

Just kidding.

There's a good diagram of the pulley system in any number of manuals. I'm interested in which manual you are using that doesn't have it.

Anywho, here's the killer setup for high-winding engines;

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Reply to
jjs

Hey -- I am truly aware that if the engine is toast I am at a fork in Ye road: dump the beast or get a new engine. It's hard to tell when stick-to-it-iveness turns into stupidity.

Me, too. Wonderbus, I am sorry I called you a beast.

(you stupid pig)

Bentley Van/Bus manual -- the green one. Am I suffering from Male Pattern Blindness here? Can't find an illustration of the pulley system. Please help those of us who cannot see!

Reply to
Mike Rocket J. Squirrel Elliot

That's Mister Pig to you.

Reply to
jjs

Reply to
Douglas

Okay, okay. I take it back. My Wonderbus is /not/ a stupid pig.

Reply to
Mike Rocket J. Squirrel Elliot

On Sat, 22 May 2004 22:09:38 -0600, "Douglas" ran around screaming and yelling:

then you are in the wrong place...personal insults are common here...heh JT

Reply to
Joey Tribiani

Mike, I can't remember there being a spacer or a washer between the pulley and the alternator body, not the kind you describe. There should be one sort of spacer looking thing that slips over the shaft, but it's more like a piece of pipe. Very thin, but deep. Can't remember measurements. Other than that, no washer.

I have *made* washers for this purpose though, so I could space the pulley out some. So it would line up with the lower pulley. Both were aftermarket items, and didn't fit right. (Go figure... duhh)

Sounds like your alternator may have a wrong type pulley on it, and the PO tried to remedy this by fitting the washer-spacer in there. As long as it's of proper size and doesn't hit the alternator body itself, it should work.

I'd replace the "supposedly alternator" pulley with an Alternator Pulley. Seems to me there are different designs, with small differences in dimensions. There are 3-4 different crank pulleys too, from the factory.

Jan

Reply to
Jan Andersson

Interesting. So here's what I found here, reading rearwards from alternator face:

Alternator Face, Washer, about 25 - 30 mm diameter, 4mm thick, dished. Oversize hole. Pulley half, front, keyed to align with crescent moon key thing, (shims) Pulley half, rear, Double-"D" hole, (shims) Pressure dome thing Nut

One more question, just to confirm:

My alternator bolts to the doghouse like generator, as shown in Bentleys. The alternators shown in Bentleys have a different mounting, but mine uses the simpler four-bolt method. To replace the alternator, I will need to pull the engine? And how does one get the blower fan off the alternator shaft?

Well, that's two more questions.

>
Reply to
Mike Rocket J. Squirrel Elliot

All else sound right except for the washer. is there a piece of tubing snugly fit around the shaft, almost completely pushed into the alternator body, barely visible? You may not even realize it's a separate part. That's what I see on mine. The Pulley half sits against it when tigthened down. Any washer you fit in between pulley half and alternator, should be equally snug fit and stop where it meets this inner spacer tube thingy. Because of the woodruff key, the spacer must have a corresponding notch filed on the inside rim, for the two to be able to share the same space. MAYBE whoever put the spacer in there, didn't bother to do this and fitted an oversize spacer in there instead, to clear the key. I wouldn't be surprised if it sat crooked and made the pulley wobble.

Err... no difference between alternator and generator in the way they attach to the fan housing. Can you alaborate? The big cover plate has those 4 6mm bolts/screws in the corners, with which you attach it to the fan shroud. The big round plate attaches to the alternator body by way of two 6mm nuts, conveniently hidden by the fan. Can't get at them until you remove the fan.

Pretty much, yes. Fan shroud must come so far up that there's not enough room to lift it in the engine bay. It's a major hassle, alsthough I have done it on some vehicle. Forgot what, and there likely were non-stock parts on the engine.

The way to get it off: the fan should have two holes in it, away from the center. A special VW tool will fit into these holes.. (you can make one fairly easily, you'll figure it out when you see it) and would offer you an "arm" to leverage the large (36mm) socket & cheater bar combo against, when loosening or tightening the fan hub nut.

Jan

Reply to
Jan Andersson

The pulley may have been bent by having its halves tightened with the belt pinched in there. You have to be careful and rotate the pulley while tightening it, so that you give the belt a chance to "walk" up inside the pulley halves as they are drawn together.

It's possible that the pulley was bent earlier, either by the failing belt or by a previous installation. I've also seen pulleys which were actually broken because a voltage regulator was occasionally sticking, which pulled hard on the belt and pulled it down into the V-groove, wedging the pulley halves apart. I've only seen this on generator cars. If this is an alternator with a built in regulator, I wouldn't expect this to happen to you.

I'm not familiar with the usual Bosch alternator construction, but, assuming they are like the generators, there should be a thin tube pressed onto the shaft, which should protrude slightly from the alternator housing. The pulley hub would press up against the outside end of that tube.

This sounds like someone's kludge. Since type 1 generator and alternator pulleys are different, you may have the wrong pulley. With either pulley, however, the hub should be a good fit on the shaft and will be a solid piece of steel. It should not be possible for it to get pushed off and made to wiggle. I suspect your pulley flanges are bent. Since you need a new one, make sure you get the right one. The right one is one for a 75 or later beetle.

I expected to find this in the orange late beetle Bentley, but it's not there either. They just didn't bother to show exploded views of the alternators.

This is one of the great advantages to the type 3 and 4 engines: The engine cooling continues even after the belt breaks. Those have their cooling fans mounted right on the crankshaft. OTOH, you're in the same boat as the other 99% of the cars on the road, since their belts all drive their water pumps.

How long did your wife continue to run the engine after the lights came on?

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

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