Generator Pulley Sizes.

Phil Gillespie

Well-known member
1939 Standard Coupe fitted with 2 brush generator. Fan bolted to pulley. Single vee belt type.
Started it up and a rattling noise from generator. Pulled it off for inspection.
In the process of stripping it managed to break a piece off the vee belt area!!
I found another repaired pulley and so fitted that one.
The one I damaged was 3.58" OD Part No on pulley 74.10130.
The one I fitted was 4.38" OD only No on this was S4?.


According to Green Bible the correct pulley for 39 is a 4.38" pulley so it appears the pulley of smaller diameter was not correct? This would give some extra genertor rpms. Now the correct size one is on so its always hard to be sure over the years whats really correct. This generator would be rated at 28 amps?


Would the smaller diameter pulley be from a 3 brush earlier generator?
Seems these pulleys especially with the bolt on fan are a little hard to come by.


Phil NZ
 
Phil Others will know more about pully sizes offerd ,but I have looked at the possibility of maching the early 3 brush pully to fit the later 2 brush shaft when I was doing alternater conversions and it couldn't easily done ,Ted
 
If you hear any vibration from the fan, carefully check it for crack between the blades and the hub. Any found will eventually cause a blade to break, usually damaging or destroying the radiator. Same is true for any blades which are bent, loose, or otherwise distorted. Pulleys on old Fords require a belt pitch that matches the groove. Over tightening the wrong belt to reduce slippage will cause damage to the bearings and bushings of the generator and water pumps.
 
Phil Others will know more about pully sizes offerd ,but I have looked at the possibility of maching the early 3 brush pully to fit the later 2 brush shaft when I was doing alternater conversions and it couldn't easily done ,Ted


Yes I see the earlier ones have a smaller boss for the smaller diameter shaft and can see how it would be difficult to machine for the larger shaft dia of the 2 brush generator.
just wondered about the one I damaged the 3.58" daimeter one part No 74.10130 what one it initially belonged to. Most listec Green Bible page 477.
Phil NZ
 
If you hear any vibration from the fan, carefully check it for crack between the blades and the hub. Any found will eventually cause a blade to break, usually damaging or destroying the radiator. Same is true for any blades which are bent, loose, or otherwise distorted. Pulleys on old Fords require a belt pitch that matches the groove. Over tightening the wrong belt to reduce slippage will cause damage to the bearings and bushings of the generator and water pumps.



What had happened in my case was the back side of the pulley where the cooling fins are located was catching on the front side of the genertor end cover, hence the noise. Just eased it a little in this area on the fins to ensure a clearance in this area. Fan blades, its a 4 blade fan are solid without defects.
Phil NZ
 
Phil,
The 74-10130 pulley is for 1938-39 60 hp engines with 2-brush generators. A rare animal for sure.
 
Phil,
The 74-10130 pulley is for 1938-39 60 hp engines with 2-brush generators. A rare animal for sure.


John appreciate your clarification. That was the one I damaged and was on the 85 hp flathead. Now the larger diameter one is fitted and now correct.
Took it for a run today and all quiet. Still able to use existing belt with the slightly larger one.Nice to know and always appreciate assistance.


Phil NZ
 
Dredging up an old discussion here.

I'm trying to identify the application of this generator pulley. The part number is 40 10130 (maybe a CR suffix?). Diameter is about 3.18" and it fits a 19/32" (.593") shaft. I looked in the green book on pages 458-459 and see a couple pulleys of this diameter, but not with the 40 prefix. Pages 468 - 469 list the various 10130 series pulleys, but none with the 40 prefix.

I rebuild generators on the side and am trying to get a few more ready for Hershey. If I know the application, I may build a generator for it. Thanks.
Steve
 

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ndnchf
The 40-10130-C pulley was originally on a 40-10000-B generator which is the 18 amp version instead of the normal 12 amp generator. I think Ford called this a "high capacity" or "police" generator where extra electrical accessories required more power from the generator
The application was originally for Model 46 but was also used for Model 48, 77 and 78 generators.
 
ndnchf
The 40-10130-C pulley was originally on a 40-10000-B generator which is the 18 amp version instead of the normal 12 amp generator. I think Ford called this a "high capacity" or "police" generator where extra electrical accessories required more power from the generator
The application was originally for Model 46 but was also used for Model 48, 77 and 78 generators.

Dave - according to the green book the 40-10000-B generator used a 4.38" diameter pulley. This is 3.18".
 
The Canadian parts book show 40-10130-CR Pulley(generator)
2" dia. at bottom of vee. Used for obtaining normal charging rates at low driving speeds. For Models 46, 48, 77, 78. 1935-37.
The 1937 US parts book shows 40-10130-C use with 40-10000-B
for obtaining normal charging rates at low driving speeds.
 
Last edited:
The Canadian parts book show 40-10130-CR Pulley(generator)
2" dia. at bottom of vee. Used for obtaining normal charging rates at low driving speeds. For Models 46, 48, 77, 78. 1935-37.
The 1937 US parts book shows 40-10130-C use with 40-10000-B
for obtaining normal charging rates at low driving speeds.

That seems to be a march. This one measures 2" at the bottom of the groove. So would this be a Canadian pulley? Thanks!
Steve
 
To me, the part numbers mean nothing. What do you do with the car? The smaller diameter will spin the gennie faster, good for the parade car, or driving a lot in town, but will make more fan noise on the highway. Large diameter will spin the fan slower for less noise at high speed. The one that fits your gennie shaft is correct, the size is up to your intended use
 
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