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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Fri Mar 08, 2019 6:23 am Post subject: 38a generator - cast iron pulley fitting |
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So I'm nearly finished fitting a 38 amp generator onto my 71 bus. I've got the right backing plate, fan hub, generator, and cast iron pulley. Last night when I tried to swap out the 30a pulley for the 38a pulley, the cast iron pulley rubs on the back face of the generator. The two long machine screws that hold the generator sandwich together are rubbing on the back of my cast iron pulley.
This 38a generator is a rebuilt Bosch unit from Wolfsburg West. Am I missing a spacer or something? If it's an original 38 amp generator body and a pulley from between 68 and 71, they should be fitting if I have all the parts. So I must be missing some kind of spacer or bearing that goes in between the fixed housing end piece and my pulley that's flying around.
If someone could help me out by taking a photo or telling me a part number or something along those lines, it would be much appreciated. |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Fri Mar 08, 2019 7:18 am Post subject: Re: 38a generator - cast iron pulley fitting |
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How about a picture of these offending screws?, I don't recall anything sticking out of mine, it's still dark right now but I'll have a look later. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Fri Mar 08, 2019 8:19 am Post subject: Re: 38a generator - cast iron pulley fitting |
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I seem to recall that there is a small spacer that goes on a 38 amp between the pulley and bearing. I looked on the fiche and it might be pictorial number 25A on fiche 92 but I can't tell if that is it or not. VW calls it a washer but it looks like a small top hat in the fiche. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Jack_O_Trades Samba Member
Joined: August 14, 2014 Posts: 188 Location: Bay Area CA
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Posted: Fri Mar 08, 2019 10:47 am Post subject: Re: 38a generator - cast iron pulley fitting |
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I just rebuilt mine. There are spacers that go on both ends.
Here, you can see the spacer as the last item on the shaft before the pulley
Here you can see the gap between the pulley and body
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kreemoweet Samba Member
Joined: March 13, 2008 Posts: 3889 Location: Seattle, WA
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Posted: Fri Mar 08, 2019 11:16 am Post subject: Re: 38a generator - cast iron pulley fitting |
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All the generators/alternators used in these old VW's have spacer rings pressed onto the
shaft, which stick out from the gen/alt body enough so the pulley (and fan hub on the other end)
can seat on it and not rub. For some reason, "rebuilders" frequently forget to put this thing back on, or
use parts where a different-thickness spacer is required, but not used. There are numerous
posts here on thesamba about folks installing a rebuilt unit, and having the pulley rub.
In the case of generators, the standard rings are 20.4 mm OD, 15 mm ID (the shaft diam.), and 6 mm thick.
I've got a dozen or so of those things from salvaged parts, I'll send one if you PM your info. Better check the
other end, too, as that one might be missing as well. _________________ '67 bug: seized by the authorities
'68 bug: seized by the authorities
'71 kombi: not yet seized by the authorities
Stop dead photo links! Post your photos to The Samba Gallery! |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Fri Mar 08, 2019 11:17 am Post subject: Re: 38a generator - cast iron pulley fitting |
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@busdaddy @Jack_O_Trades - I'll get some photos. Maybe you guys can help me figure out what's wrong. I do have a spacer in there but it only sticks out just a bit. Not enough to keep the pulley off of the housing. Ok, more to come soon. I'll take lunch in a few and go take the generator pulley off so I can take a few photos. Thanks guys! |
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Jack_O_Trades Samba Member
Joined: August 14, 2014 Posts: 188 Location: Bay Area CA
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Posted: Fri Mar 08, 2019 11:38 am Post subject: Re: 38a generator - cast iron pulley fitting |
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Took some more photos without the pulley.
If needed I can pull the end piece off to offer more detail on the stack of components
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Fri Mar 08, 2019 11:46 am Post subject: Re: 38a generator - cast iron pulley fitting |
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Okay thanks for the additional photos. It looks like your spacer sticks out further than mine does.
I slid the pulley on and turned it a few times so you can see where the screw heads rub the back of the pulley
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Jack_O_Trades Samba Member
Joined: August 14, 2014 Posts: 188 Location: Bay Area CA
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Posted: Fri Mar 08, 2019 11:50 am Post subject: Re: 38a generator - cast iron pulley fitting |
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Your screw heads are also too proud. They are supposed to be recessed in counter-bored holes. Ditch the washers
As far as the spacer goes you are probably missing the grease shields which also act as spacers/shims. Would order some shims/races from McMaster. Do not use washers as the two faces of a washer are not necessarily parallel. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Fri Mar 08, 2019 11:55 am Post subject: Re: 38a generator - cast iron pulley fitting |
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If I take those screws out to remove the washers, are the guts of the generator going to fall around or cause me not to be able to get them back in for some reason? Or do I have to/should I take the generator out to do this work?
I'm familiar with McMaster. Do these shims/races slip behind the collar/spacer? I can slide that collar off of the shaft and there is a narrow corridor around the shaft. Do you have a photo of the shims/races that you are taking about? |
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Jack_O_Trades Samba Member
Joined: August 14, 2014 Posts: 188 Location: Bay Area CA
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Posted: Fri Mar 08, 2019 12:11 pm Post subject: Re: 38a generator - cast iron pulley fitting |
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There are a couple of approaches you can take.
First off, you will not be able to remove the screws until you disassemble the fan side because they are used to mount the generator to the backing plate and have nuts on them.
Once you have liberated the generator you can remove the screws one at a time to remove the washers. When you reinstall the screws, you need to be careful how the coil wiring is routed internally. I prefer to have the coil wires outside of the screws between the screws and the can so that there is minimal risk for chaffing with the armature.
As far as the correct spacing. My spacer is 3mm proud of the end cap. I don't know if this is correct as I just rebuilt this generator and have not checked it for belt alignment on my engine. At the minimum, you don't want the pulley rubbing on anything.
Here are the shims
https://www.mcmaster.com/92927a179
They have an OD of 20mm, the bore on the cap is 21mm so they would fit above or below your spacer.
The easy way is to stack them inside the bore. The correct way is to probably pull apart your generator and look at what you have to see what you are missing. Either way will probably work.
The reason I think your grease shields may be missing is because the original bearings were not shielded, hence the grease shields. The newer bearings used for rebuilds are shielded so the original shields may have been tossed.
That being said. It looks like your spacer is short by 2-2.5 mm. The missing shields would only make up for about .5mm.
So, maybe you have the wrong spacer. My spacer is 6mm thick. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Fri Mar 08, 2019 12:43 pm Post subject: Re: 38a generator - cast iron pulley fitting |
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@Jack_O_Trades, thanks for the info and the link. I'll come back with some more photos later today or tomorrow. I just had this engine out last weekend to put the generator in and I guess it's coming out again. Can't win for losing. I should've waited until i had the pulley before switching them out. #$@&%*! |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Fri Mar 08, 2019 1:00 pm Post subject: Re: 38a generator - cast iron pulley fitting |
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If you can reach around and get the nut off the fan and get the 2 lower bolts or screws out of the backing plate down between the manifold and shroud you can remove the generator with the engine installed, if any of those are a problem the engine has to come out. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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mikedjames Samba Member
Joined: July 02, 2012 Posts: 2714 Location: Hamble, Hampshire, UK
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Posted: Fri Mar 08, 2019 1:54 pm Post subject: Re: 38a generator - cast iron pulley fitting |
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When I hit similar problems with an alternator I had rebuilt, I bought a set of 0.020" shim washers on eBay and stacked them until the pulley stopped rubbing. _________________ Ancient vehicles and vessels
1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.
1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy |
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Amskeptic Samba Member
Joined: October 18, 2002 Posts: 8568 Location: All Across The Country
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Posted: Fri Mar 08, 2019 6:51 pm Post subject: Re: 38a generator - cast iron pulley fitting |
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hylomatt wrote: |
@Jack_O_Trades, thanks for the info and the link. I'll come back with some more photos later today or tomorrow. I just had this engine out last weekend to put the generator in and I guess it's coming out again. Can't win for losing. I should've waited until i had the pulley before switching them out. #$@&%*! |
There will be no swearing around here:
https://itinerant-air-cooled.com/viewtopic.php?f=76&t=13387#p226031
_________________ www.itinerant-air-cooled.com |
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alikatcraig Samba Member
Joined: September 09, 2007 Posts: 554 Location: Anaheim, CA
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Posted: Tue Mar 12, 2019 6:27 am Post subject: Re: 38a generator - cast iron pulley fitting |
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Berg sells a shim. GB 438 _________________ 1967 Ghia
1971 Deluxe Microbus
1974 Convertible Bug
1973 Standard Bug
1998 Mexican Bug |
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74 Thing Samba Member
Joined: September 02, 2004 Posts: 7374
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