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V BELTS WHERE FROM

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6K views 15 replies 9 participants last post by  evilC 
#1 ·
ok got all this info, im trying to get a 9.5x905 V-belt not toothed for my
1200 with dynamo, anyone done this and know where to get them.

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Belt Size
The fan belt used by VW has evolved over the years. They used the 9.5 x 900mm V belt for their 6-volt engines. The Continental 9.5 x 905mm V belt was later used on the newer 12v generator engines. Continental later standardized their belts to a 10 x 900mm (111-905-137B) and 10 x 905mm (OEM 111-903-137D) belt and VW came out with new OEM numbers to reflect this change.

Earlier bugs had smaller belt which was sufficient for the demands of their low wattage generators and smaller fans of their time. The 36hp engine had a fan with 24 blades and a 160 watt generator. The 40hp and 1300/1500/1600cc single-port engines had fans with 28 blades which increases the demand on the fan belt to a small degree. Plus during that time, the generator output rose from 160 watts to 360 watts. As a result, the 1500/1600cc single-port engines had a 5 hp load on the fan belt, whereas the earlier engines only had 4hp. Later, in 1971, the introduction of the doghouse cooler also meant a 5mm wider (10% increase) fan which brought the load on the belt to around 5.5hp. In 1973, the addition of the 220 watt alternator brought the belt load to a whopping 6hp. And with signs of early failures from the thin VW belts, it was time to upgrade the belt size, so the 1973 alternator also got a much thicker heavier duty 11.3 x 912 mm v-belt.

In regards to what belt will work for an engine with an alternator or generator - thicker is better. For the most part, you can run the older thinner belts in a newer engine with an alternator and likewise can run the thicker newer belt in an older engine with a generator. You will just have to add or subtract shims as needed. Properly fitted thicker quality belts should last longer than thinner belts in any VW.

Also note that belts from different manufactures also vary to some degree in true size and different combinations of pulleys and belts can have a surprising impact on belt tightness. The stock pulleys for the generators and alternators are the same, but these pulleys are often replaced with aftermarket ones by previous owners, so you may have to go with a longer or shorter belt to get the perfect fit. Because of this, you may need to experiment with several belts, remember which one works for your auto and remember to buy a spare.

Stock VW 1600 DP with Alternator Belt:
Brand Part Number Size US Conversion Metric Conversion
OEM 111-903-137-E 11.3 x 912mm 0.4448 x 35.9055" 11.3 x 912mm
Gates 7355 13/32" x 36 1/8" 0.4063 x 36.125" 10.3 x 917.6mm
Altrom (NAPA) ATM 11X912
Gatorback (Good Year) 15361 0.438" x 35.500" 0.438" x 35.500" 11.1 x 901.7mm
Dayco 15358 0.44" x 35.75" (36.3" outside circumference 36°) 0.44" x 35.75" 11.2 x 908.1mm
Goodyear 13355
Metric 10X910
Master Pro (O'Reilly) 7355
Master Pro (O'Reilly) 15355
Duralast (AutoZone) 15355 0.438 x 35.500" 0.438 x 35.500" 11.1 x 901.7mm

Euro:
Bosch 1987947500
Continental 11.3-912
Continental 6578116
DIN 11.3X912
Gates Europe N.V. II: 6372
Goodyear 11AV0913
Motorcraft EJD91

The US Gates 7355 v-belt is supposed to fit:
Beetle 1960-1979
Campmobile 1968-1970
Karmann Ghia 1960-1974
Super Beetle 1975-1979
Thing 1973-1974

In case you need to convert inches to and from mm:
mm
inches



Loose Belt
If your belt is too loose with all the shims removed, you may have a one off pulley or worn alternator bearing. A slightly smaller than stock belt is one potential fix. The Gates 7350 (13/32" x 35 5/8") should do the trick.
Brand Part Number Size US Conversion Metric Conversion
Gates 7350 13/32" x 35 5/8" 0.4063 x 35.6250" 10.3 x 904.9mm
Altrom (NAPA) 10X900
Gatorback (Good Year) 15356 0.438" x 35.000" 0.438" x 35.000" 11.1 x 889.0mm
Dayco 15350 0.44" x 35" (35.6" outside circumference 36°) 0.44" x 35" 11.2 x 889mm
Dayco 15355 0.44" x 35.5" (36.1" outside circumference 36°) 0.44" x 35.5" 11.2 x 901.7mm
Goodyear 13351
Metric 10X900
Metric 10X890
Master Pro (O'Reilly) 7350
Master Pro (O'Reilly) 15350
Duralast (AutoZone) 17350 (13AV0890) 1.3cm x 89cm 0.512 x 35.0" 13 x 890mm
Duralast (AutoZone) 17345 (13AV0875) 1.3cm x 87.5cm 0.512 x 34.4" 13 x 875mm

Tight Belt
If your stock sized belt is too tight, the the Gates 7360 at 36 inches (914.4mm) should work for you.
Brand Part Number Size US Conversion Metric Conversion
Gates 7360 13/32" x 36 5/8" 0.4063 x 36.6250" 10.3188 x 930.275mm
Altrom (NAPA) 10X913
Altrom (NAPA) 10X918SET
Altrom (NAPA) 10X920
Gatorback (Good Year) 15366 0.438" x 36.000" 0.438" x 36.000" 11.1 x 914.4mm
Dayco 15360 0.44" x 36 (36.6" outside circumference 36°) 0.44" x 36 11.176 x 914.4mm
Goodyear 13361
Metric 10X915
Master Pro (O'Reilly) 7360
Master Pro (O'Reilly) 15360
Duralast (AutoZone) 17360 (13AV0915) 1.3cm x 91.5cm 0.512 x 36.0" 13 x 915mm
Duralast (AutoZone) 17365 (13AV0925) 1.3cm x 92.5cm 0.512 x 36.4" 13 x 925mm


Continental 9.5 x 905mm for vintage VW diehards

12V Generator Belt
Stock VW 1600 with 12V Generator used a thinner belt (but can still use a thicker one too):
Brand Part Number Size
OEM 1966 to 1973 111-903-137-D 10 x 905 mm
Volvo 973547 9.5 x 905mm
Mercedes 006-997-02-92 10 x 910mm (37 3/4 inch)
Altrom (NAPA) ATM 10X905 10 x 905 mm
EMPI 00-9928-B 9.5 x 905mm

If this is too loose, you can try a 10 x 900mm belt used on the 6V VWs (OEM 111-905-137B)
Brand Part Number Size
OEM 1947-1966 111-905-137B 10 x 900 mm
Altrom (NAPA)
ATM 10X900
 
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#6 · (Edited)
That's odd. When I emailed GSF a few months ago, they said that they didn't stock them any more. I guess it must be ring up the various GSF branches to get them. What's the stock number for the optibelt ones (eg. is it different to the useless toothed fan belt variety) ?

I have also tried to order Beru UX79 spark plugs from thier website (using thier old stock code BBUX79) but they don't seem to be there anymore :( and they only sell the rubbish Bosch spark plugs. I guess I'll have to try and find another Beru spark plug stockist.
 
#8 ·
ok got all this info, im trying to get a 9.5x905 V-belt not toothed for my
1200 with dynamo, anyone done this and know where to get them.

----------------------------------

Loose Belt
If your belt is too loose with all the shims removed, you may have a one off pulley or worn alternator bearing. A slightly smaller than stock belt is one potential fix. The Gates 7350 (13/32" x 35 5/8") should do the trick.

Is this the same for a dynamo?
 
#10 ·
i use about 150/ 200 bosch plugs per year, air and water cooled, ive never had one problem, even since they went to the asian manf'g sector in about '95. thats a lot of plugs.. any brand, any part is being ripped off these days, plugs that fail will be snides.
 
#11 ·
ok got all this info, im trying to get a 9.5x905 V-belt not toothed for my
1200 with dynamo, anyone done this and know where to get them.

----------------------------------------------------

....................
Great info.

I haven't bought auto belts since early '70s when I changed to industrial belts for all of my V and now polyV belts. Since that time I can't remember a single industrial belt failing and they have had to transmit excessive torque. In fact the auto belts that came with the cars or a kit have all generally had to be replaced at some stage. I use Gates Quad or High Power and they are available in a huge range of sizes with the polyV belts being made to suit. They are available from belt and bearing suppliers so look them up in yellow pages for local stockists.

The first industrial belt I bought was on the recommendation of Andy Chesman for an Imp engine that regularly saw 8,000rpm and would throw autobelts on the overrun due to the whip. The Gates High Power solved the problem without having to resort to deep flanged pulleys.
 
#16 ·
I don't doubt the reasoning but all the engines I have used the Gates belts on have had alternators and all worked perfectly without any noticeable distortion. I would think that if it were an issue then it would be difficult to tension the belt properly with consequential slipping. The worst situation I have used them in was on a 3.1ltr 4 cylinder diesel whose primary belt powered the alternator and water pump and then a secondary belt was powered by the waterpump to power the powersteering belt. With auto belts the assembly slipped all the time especially when the powersteering was under load. With a quad power on the primary and Hi power on the secondary the problem was solved without knackering the water pump bearings that happened first time around with the auto belts on extra tension to get some semblance of drive
 
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