Samba Machinists! Question Re: Brake Drum Machining

[sjbartnik]

Hi guys,
So I’m trying to get my Type 3 rear drums machined to correct some out-of-roundness on the friction surface. As I’m sure you’re all aware, the days of the average repair shop or parts store being able to turn drums seem to be long gone.

I have been working the phones here in Brooklyn and finally after a web of referrals was sent to a truck brake shop in north Brooklyn. This shop was awesome - old school. They had the requisite old guy machinist and he was an awesome dude. Had his own corner of the shop, wooden shelves and workbenches galore full of ancient tools and devices. He was game to help out.

So we found that the drums fit over the shaft on his lathe, but the problem came in that he did not have conical adapters small enough to fit inside the splined area in order to center the drum on the shaft. Everything he had was just too big. This seems to be the biggest obstacle to getting these rear drums turned even when you find a guy who still has a lathe.

I would be happy to buy said adapters from somewhere if anyone could guide me as to what I need. The guy said if I could get the adapters he’d happily turn the drums for me.

So that’s one option. The other question I have is, is this something that just a straight machine shop should be able to handle (as opposed to an auto repair shop with a specific brake lathe)? Is a brake drum something that an average machinist should be able to chuck up on a standard lathe?

Thanks in advance for any info, Machinists of the Samba.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[busdaddy]

If the lathe has a big enough swing it could happen, you'd need a stub axle to chuck with the drum on it backwards.
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[QRP]

Did you bring him the hub or just the drum?

Seems like it shouldn't be to tough.

Have the drum bolted to the hub when its being turned so it'll run true.

Unless it's an early wide 5

[evanfrucht]

The right shop should have the wide five attachment, or atleast an adjustable one. A regular lathe could work but I imagine a specific brake turnng machine would make the most sense. At least I'm pretty sure.
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1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[modok]

the way an ammco brake lathe would work is
Small tapered cones interface with the the chamfer at either end of the drum splines.
You could make the tapered cones or buy them.
I'm not sure which ones we have, they are older than I am.

Centering on splined hole is always problematic.

[mcmscott]

[Cusser]

This is why I bought new rear brake drums for my 1970; was not able to locate a shop in the Prescott area to do the machining.

I got 2 rear drums from RockAuto, described as Raybestos, and when they arrived they stated "made in Germany".
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[esde]

An old axle shaft is the way.
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[sjbartnik]

Sorry, I should have mentioned: yes these are early wide five drums, so no hub to speak of.

The only new drums available are Brazilian and I have heard they are kind of suck.

I just want my braking to be extra smooooooth but that damn right rear drum has a high spot
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[evanfrucht]

Ya now I remember looking into this at ome time. A lot of shops don't have the proper fixture anymore, or someone who knows how to use them even if they do. So many places that turn drums will turn you down. For me it made the most sense to buy all new ones since I ended up finding out a couple of my original ones were too worn down/scored. I say just get the IAP brand from Rockauto they are made in ITALY. I got them a few months ago for $40 something each... much cheaper than anywhere else. I have wide 5's too BTW.

UNLESS, if you have original VW stamped german ones and they look like they have barely any miles on them then it's worth it to find a way to have them turned IMO. But other than to retain original drums it's not worth the hassle of turning random aftermarket drums just to save money, unless maybe you have the tools and time to do it yourself.
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1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[sjbartnik]

These are OG German drums (VW logo and everything).

Unfortunately RockAuto doesn’t know that ‘65 Type 3’s exist because they were not sold in the USA until 1966. So they don’t have a listing for the ‘65 Type 3 drum. ‘66 was when the Type 3 went to 4-lug.

I’m not aware of any of the Euro manufacturers making new Type 3 wide five drums. The only ones I have seen are Brazilian.

It makes sense that somebody is still making Beetle wide five rear drums; the Beetle install base was quite a bit higher! But they are different than Type 3 drums.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[evanfrucht]

[modok]

European made replacement wide five type-3 drums must exist, because I have them on my car.
They may be NLA at the moment

The adapter cones have a part number; ammco 5796
So tell your "old guy" to buy some

[ALB]

[sjbartnik]

Fun fact, those 23.8mm wheel cylinders are originally a ‘64-‘65 Type 3 part, but Squareback-specific (hence the 361 part number).

‘64-‘65 Type 3s got the 22.2mm rear wheel cylinders except for Squarebacks which got the 23.8mm.

When the Type 3 went to front disc brakes for ‘66, the rear wheel cylinders went to 22.2mm across the whole model line.

I have just installed a set of the 23.8mm cylinders in my Square which had the wrong ones in before, so we’ll see how that goes.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650