71 bus --2 alternator belts in 50 miles

[mr. lang]

I've used one of your pictures and added some measurements

Nut has 13mm
v-groove therefore has 9mm...10mm (well my paint graphic does suck and there is a optical distortion)

At least not a pulley for a 11.3mm belt and I'm pretty sure, that's your problem.
11.3mm belt not fully seated in 10mm belt pulley.
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1966 Bus | 1969 Bug | 1976 Passat LX two-door | 1984 Golf 2 C (daily driver)
There are three kinds of people: those who can count and those who can't
Und läuft ...

[Abscate]

[grapedaddy]

Although it would seem there are conflicting arguments, it now seems like I have multiple problems and there may not be an only-just-one-thing at fault. Thank you to everyone.

I have pulley alignment issues AND a belt width issue. Given that it now seems likely that I have my original 38 Amp generator pulley I need a generator belt even though I've have an alternator conversion.

Am I clear that the 71 38Amp generator pulley requires a 111903137D 9.5 X 905mm belt?

The engine builder/installer in Wytheville VA has referred me to his friend's shop in Chilhowie, VA and has delivered an alternator pulley and an original VW alternator stand. I have German Continental 9.5 X 905 belts on the way, new 11.3 X 912 belts on hand and my bus made it to the Chilhowie shop today without twisting a belt. (I didn't drive over 50 - 55mph).

Things are looking good for Buttercup.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[SGKent]

[aeromech]

Just install a generator pulley and one that’s quality. Those $7 jobs will leave you stranded. Then get the 905 belt and be happy once the alignment issue is satisfied
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Abscate]

[grapedaddy]

I saw my bus today on the lift at the shop and discovered the following:

Neither pulley was true. Both pulleys replaced. I saw a VW logo on the new crank pulley, but don't know the vintage of the new alternator pulley. There had been a spacer between the alt pulley and the alt that had to be removed. 9.5 x 905mm belts were too short, but the 11.3 x 912 was just right -- *after* adding several more shims between the alt pulley halves. A mirror in the right place now shows perfect pulley alignment. It was started briefly and the belt doesn't flop anymore when it turns. It looks like a classic all-is-well-that-ends-well, but I don't want to jinx it. The proof won't come until I drive it at 65mph for 50 miles and check the belt.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[aeromech]

I’m betting that you fixed it
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[grapedaddy]

Now sometimes it makes this osculating vibrating noise and sometime it doesn't. The following is a link to an audio wave file. It should play in your web browser without having to download it.

https://drive.google.com/file/d/1gUlBBKHLce5nbBzxf-w2Aka2yMoy1zXI/view?usp=sharing

. . .heard this noise before? It's like having a lawn mower running in my back seat and it isn't running that great either.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[SGKent]

make sure the strap on the alternator, and that the shroud side bolts are tight.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[grapedaddy]

The strap on the alternator and the shroud side bolts are verified tight and I can't move the fan shroud or the alternator without loosening anything.

I'm *guessing* the fan is just too close the shroud now that my pulleys line up. I'm *guessing* I'll have to loosen the alternator strap and push OR pull a milometer or 2 and hope I don't put my pulleys out of alignment and start throwing belts again.

I"m discouraged by the fact that people much more knowledgeable than myself have already tried that.

The hard part is knowing if the fan is interfering with the backing plate or the firewall side of the shroud and if moving the alternator would change anything since the backing plate would follow the alternator when I move it. That's how I visualize it in my mental simulation anyway.

If you couldn't hear much in my recording let me know. I'll dig out a better recorder. The noise I hear is not so much of the screeching noise as the fan rubs but an oscillation like something is way out of balance or out of round.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[grapedaddy]

Here is a much better recording of the Whomp, whomp, whomp vibration/noise.

https://drive.google.com/file/d/1CFmjt4LrQ4tVuwUzv_SGukvPfzUfK-2_/view?usp=sharing

It is an mp3 file that should play in your web browser. Of course, I usually tell people all day *not* to click on anything that says "click here," but click there please.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[grapedaddy]

[Solved] This problem devolved during the long troubleshooting process and multiple attempts to fix it made it worse, but in the end the source of my problem seems to be that the fan vibrated so much that the pulley alignment would drift after running the engine for a while. The second fan was much worse than the wobbly one it replaced.

I couldn't source an OEM German fan --only Brazilian aftermarket, but I ended up getting one of those from Gene Berg that had been welded and balanced to ensure I was at least getting a balanced one with the hole actually-in-the- center that wouldn't wobble so much. I had a similar problem sourcing a good enough alternator pulley, but eventually found a straight OEM used one. The too tight belt and all that vibration *may have* ruined my Alt bearings as well further contributing to the vibration, so as possible overkill I sourced a new Mexican Bosch Alt and now vibration is minimal and my pulley stays in alignment. I don't know that my Alt was damaged, but I just wanted to get it over with and be done with it replacing Alt, fan and pulley all-at-once.

I have been driving it a couple of months and all seems well regarding the fan and pulley alignment.

Now on to my fuel sender and so on. I can't find anyone who wants to touch that.
---end---
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[telford dorr]

Another factor is the alternator pulley itself. Virtually ALL aftermarket units are junk - they aren't concentric with the alternator shaft. If you watch them closely, they move in an elliptical orbit, causing the belt to loosen and tighten as it turns. This creates horrible vibrations which will eventually destroy the belt, the pulley and sooner or later the rear alternator bearing. I inspected maybe seven pulleys before I found one which would run true. That's bad QC!

Never had this problem with an OG pulley...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Abscate]

You call it bad QC, manager calls it manufacturing to price point.



Thanks for imput as always, Telford.
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.ssS!

[Spike0180]

[sodbuster]

NO! No dished backing plate for the alternator. Those were for the 38 amp generator ONLY! All Alternator conversion kits on the market come with the proper backing plate for the conversion. I betting if your alt was installed as a kit the backing plate is correct already.

What has me puzzled is why after loosening just the alternator clamp you have so much movement of the fan shroud? sounds to me like there is a lot more going on here.

[grapedaddy]

The correct NON-dished backing plate was used. I've only driven it a few hundred miles since the last intervention, but I'll be checking the belt often until I *know* it is rock solid reliable --and then I will keep checking it for good measure. I didn't mention it, but an OEM VW Alt stand was also used in the last fix.
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”

[busdaddy]

[grapedaddy]

Pulling the gas tank for all that and replacing that fuel sender was in the work order a couple of times. Mechanics in Salem, Wytheville and Chillhowie Virginia wouldn't do it. At least they told me that up front before they tried it and made a bigger mess. Apparently, there isn't much profit margin in pulling gas tanks. I can't do it and most of you guys are just too far away. USA VA 24210
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grapedaddy
1971 Westfalia "Buttercup"
2003 Westfalia "Tourmaline" (sold)
2021 MB Metris Getaway “TheDarkSide”