Mounting Porsche discs on Beetle spindles

The brake parts I had collected were a pair of rear calipers from a 95-98 Porsche 993 (911) with their corresponding discs, and 944 NA aluminium hubs. I wanted to get the hubs to fit stock beetle spindles, as this was much easier than trying to modify the 944 ones which are a different size, and different strut angle to the beetle ones. Making the Porsche hubs fit the beetle spindles could be done it two ways: Use beetle bearings and machine the hub to take spacers, or use Porsche bearings and machine spacers to fit over the beetle spindle. As the beetle spindle is shorter than the Porsche one, it was easier to machine the hubs and fit inserts. Then I can keep the beetle bearings and seals and still use beetle struts etc.

fastbughub.dwb - 0.57MB
fastbughub.dxf - 0.88MB
fastbughub.igs - 2.23MB

I approached a friend of mine who also happens to be an excellent machinist and engineer. He stepped up to the challenge, and the first job was to make some accurate technical drawings of the parts. I created these with help another friend at my place of work.

Using the CAD images the hub was superimposed on the spindle showing the size of the required spacers. Notice the 2mm (approximate) gap either end of the bearings; this was increased to 4mm by machining out the hub to give the spacer more material.

The base of the hub was machined to clear the spindle, and provide space for the seal. An aluminium spacer was pressed in to hold the seal in the correct position.

In order to machine the hub accurately in relation to the disc mounting face, tools where made up to hold the hub on this surface, rather than just mounting the hub in a chuck:

The finished hubs showing inserts and also bearing shells pressed in:

The total run-out of the assembled system is less than 0.01mm.

The next task is to create a metal plate to bolt to the drum brake spindle and hold the caliper.


I have finally made it to the point that its now paintable. All welding has been done, and all holes cut. It got to the point that I just wanted it gone, so some areas I haven't cleaned up as much as I would like, but the body shop can do that.

The front spoiler is completed. I cut the hole for the oil cooler, and drilled all the rivet holes. Covering the hole will be an aliminium surround with a mesh screen. I joggled the hole to hold the mesh in place. I cut the fuel filler cap hole using a holesaw of exactly the right size.

Looking for a body shop was an interesting experience! I had a couple of places give me massive quotes for doing the work. One quoted around £7000 for the work, but that sounded like a 'I don't want to do it' quote. One place quoted me around £3000 for it, but once the paperwork came through it was £3000 + VAT! At least they came round; One body shop near me said they would come round on a Monday night. I waited around for them, but no-one turned up. Next day I called them, and the guy said 'oh sh*t, sorry, will be around tonight'. Waited around again, nothing. Now, I don't know about you, but that really p*sses me of. Thats two hours of my life I will never get back! Called them the next day:

Me: Hello, you were supposed to come out and give me a quote again
last night?
Them: Oh, he must have forgotten again. Are you there now?
Me: No, I am at work, and to be honest, I don't really want a quote now, I would just like to know why you stood me up twice?
Them: You won't get far with that attitude!
Me: Huh? What attitude, you stood me up!
Them: Well your attitude sucks..
Me: You can't understand why I am a little p*ssed off?
Them: No, and I expect your car is a bit of a pig anyway!
And with that, he put the phone down! Well thanks, but no thanks. Quite how he expects to run a business like that I don't know. Anyway I had a look around their workshop and its a pretty small dirty place, so I don't expect the work would have been any good.

Eventualy I found another body shop who were quite happy to do it for a much more reasonable fee, so got the business. I borrowed a flatbed trailer from a friend, loaded it up and took it down.

There is quite a pile of things to paint as well as the body: four wings, 2 doors, a bonnet, decklid, airdam, spoiler, engine fan shroud, rear valence and a bucket of smaller things such as headlight rings and door handles. In order to paint the chromed items such as headlight rings you really need to remove the chrome as the paint will eventually come off it. To do this I mounted a zirconium flap disk on the grinder then mounted the grinder in the vice, using a bolt in the handle hole. This then allowed me to hold the part in two hands, and carefully take all the chrome off.

Now all I can do it wait for the painting to be done, I can't wait!