78 Flywheel Bolts Source

[78westfalia]

Hello,
Does anyone know where to source the flywheel bolts for a 78 Westy? Part # N0143351. Bus Depot lists the part, but they’re currently on back Order with eta 3-5 weeks. Even then they’re not guaranteed to come in. Any help is greatly appreciated.

Thanks!
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78' Champagne Edition Westfalia

[SGKent]

VWHeritage shows 6. Might find them at Pelican Parts or Auto Atlanta. FYI I have read that the 914-4 bolts are different length.
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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

[sjbartnik]

FYI for searching purposes...

a little google-fu came up with a spec: they are flange bolts, M12 x 1.5 thread pitch x 22mm length.

These seem to be surprisingly hard to find as most M12 flange bolts available through the usual suspects are 1.75 thread pitch.

I checked Bel-Metric, Fastenal, and McMaster-Carr. No M12 x 1.5 flange bolts.

EDIT: this place Bolt Depot (no experience with them) has them in M12 x 1.5 in either 20mm or 25mm lengths, in yellow zinc-plated steel, grade 8.8:

pasting the link in made the post disappear, so search boltdepot.com and you will find it.

I do not know if that is strong enough for this application or if they should be 10.9.

Could you use a regular (non-flange) bolt with a washer? ¯\_(ツ)_/¯
I don't know but I'm not sure I'd want to be the first guy to try it.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[SGKent]

They are NLA from VW. Unless someone has them in stock it looks like a loosing chase. The 914-4 bolt is a different number because it is supposedly longer and bottoms when using a bus flywheel and crank.
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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

[Wildthings]

Check GoWesty, VanCafe, and Vanagain. The watercooled and aircooled Vanagan uses very close to the same bolt as a Bay but they have a different head and don't use the soft lock plate under the head. The torque is 81 ft*lbs according to the GoWesty site.

https://www.gowesty.com/product/-/24083/flywheel-flexplate-bolt-kit?v=

Never actually used these on a Type 4, so give GoWesty a call to see what they say.

[Hoody]

The Type4 store.

[raygreenwood]

[airschooled]

What about the Schnorr finishing on the underside of the flange? Or is that assumed in any flange bolt?

Robbie
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[raygreenwood]

[Manfred58sc]

I have a couple sets, PM for details
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Fat chick owner/operator

[Abscate]

How about buying the too-long bolts, put a die or a hard nut on them, cut to length, chase thread. Install to torque and add blue Loctite elixir to the clean and dry thread per spec.
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[raygreenwood]

[78westfalia]

[raygreenwood]

Here is a little more information on these bolts. I have added them to my....."when you have 5 minutes to waste and want to Google something you have been looking for"....list.

It may help others find some when they have time to look.

I have plenty of used bolts in my collection of parts....but really...correctly....you should replace these bolts at about the same interval as piston rod bolts. They are under a lot of stress and highly torqued.

So......these DIN 6921 bolts.....meaning fully threads serrated flange head. DIN 6921 can come either serrated or not serrated.
Strength wise....they are actually metric class 100.

In this class....they are case hardened and have tensile strength of 150,800 to 174,000 psi.....so they are slightly above class 10.9 and just few thousand psi short of class 12.9.

Looking at an original bolt.....and I remember talking about this in another thread somewhere......this is a pretty bad ass design locking wise. Flange head so no load bearibg washer necessary.

The flywheel generally being cast iron or cast steel.....is brittle and creates small chips when teeth bite into its surface. Through flexing and vibration those chips turn to dust and just locking these serrated bolts to the flywheel means they will sooner or layer work loose with a black powdery residue under them. So.....you get the big five hole lock washer. Teeth bite into that....and it can never turn to loosen from heat cycling and vibration because there are 4 other bolts keeping from turning.

So if you can get serrated flange bolts......it would be the best.

However that being said....if you can get bolts of usable tensile strength with or without flanges that have no serrations.....I think that if you have a good automatic center punch you can put a ring of indentations on the mating face of the bolt ...and those will have sharp raised edges.....and that should do the same thing.

But.....you should get flanged bolts either way. Without a flange.....a bolt really needs a washer to spread load.

Ill post some pics later of a bolt that was center punched and some details of the ribs on a stock one. Ray

[Wildthings]

[SGKent]

flywheel bolts sometimes crystalize in general. Anyone who has been burned by that or snapped one torquing it will always replace them if they have any miles on them. Unfortunately those only once in a lifetime things add up.
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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

[sjbartnik]

[raygreenwood]

[Wildthings]

[SGKent]

Bus 2 litre ..... N0143351 M12 x 1.5 x 22

914-4 & 912E N014336B M12 x 1.5 x 25

I listed some 914-4 ones in classifieds. I do not know if they will work on a bus because they are 3mm longer than the VW part.
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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