Aircooled VW South Africa

I like Tom Bishop's idea of sealed bearings, I can recall we put them on a standard swing arm Beetle a few years ago as well..

Can anyone explain to me why it is roller bearings on one side and ball bearings on the other? According to the Type 3 boffins on TS, it is normal?

The ball bearing locates the axle (circlip(15) holds the bearing) and takes all of the axial load, the roller bearing takes the majority of the radial load. If you have two ball bearings the spacer(11) has to be exactally the right lenght(about +/- .02 mm) or the bearings will be preloaded axially and this will prematurelly wear out the bearings.

The roller/ball bearing set up is standard on all IRS beetles and type 3's( IRS bay window kombis are the same only bigger bearings). All the IRS trailing arms(type1 & type3) are the same apart for the mounting hole differences between the single and twin spring plate versions(all type 3 were twin spingplate and some type 1( semi-auto))

I would replace the trailing arm bearings you have shown. The washers(30) on the pivot bolts(31) are used to align the trailing arms to ensue correct axle lenghts. Two on the outside or one in and one out.

http://www.thesamba.com/vw/forum/viewto ... highlight=

Bearings

x2 6206 C3 62x30x16

x2 315840 (NU 206) 62x30x16

Seals

x4 62x44.5x10

Thanks for the valuable info, Mackay!

Tonight I removed the old pivot bolt bush and rubbers from one of the trailing arms. Pushed it out with the bench vice after oiling it up, and it came out quite easily. The bush of the new red urethane rubbers are indeed too big as Tom Bishop said, but it looks like I will be able to use the original bushes (strangely enough, a two-piece per side) with the new rubbers, pics to follow tomorrow.

Pine, I would replace the bearings now. Just think of all the work you had to do to get those bearings out. You are gonna get your bug going in a few months time and 100 km's down the road one of those bearings are gonna pack up. Murphy's Law. My 5c. Your call.

Yip, I will replace them

In the pic below you can see the original VW trailing arm pivot bolt rubbers and bushes to left, and the replacement urethane rubbers and (single piece) bush to the right. As Tom Bishop mentioned earlier, the inner diameter of the replacement bush is about 1mm larger than the original bushes, so I will use the two genuine VW bushes with the urethane rubbers.




These are the two IRS trailing arms that were fitted to a racing sandmaster (still in the process of being cleaned). As you can see the shock mounting brackets have been removed, and the arms were 'boxed' b.m.o strengthening welds at various places to make it stronger and more durable - not neccesary for the mild use that I intend to use HW2 for though. I doubt that wirebrushing is going to be adequate, so I'll have them sand blasted and powder coated in the new year, after the replacement shock brackets have been welded on.




Cleaned out the inner parts where the bearings go, looking through it kinda looks like the 007 gun barrel intro at the beginning of a Bond movie



...you see what I mean?



Well I guess I got my license - to wirebrush now

Removed the IRS 'box from the 1302 the weekend. After some queries on TS w.r.t the 'AT' stamped number, I have learned that it is actually a 1303 'box, and specifically also fitted to the cabriolet. It has the following ratios, which makes it perfect for my intended use in the buggy, namely normal street cruising:

3.875 R&P with 3.78/2.06/1.26/.93 gears




Gearbox code - decoded

AT 07 09 3
Built Sept 07, 1973

It currently has the wrong nosecone, but it will be replaced by this one, which is correct for the chassis. Pic taken after I have cleaned it, note the reverse light switch at the front right, just above the part number

These IRS 'boxes are pure unobtainium!
Could this be the first IRS buggy in SA?

I believe there to be quite a few, especially off-road racers. A while ago I saw a new Lolette body being pickup up at Volkspares, that was also headed for an IRS chassis. It looked awesome in colour-matched Kawasaki green

and that rotor buggy i posted pics of a while ago had irs suspesion with bilstein shocks alround...aperntly worth 20 k...

Here's a little experiment I did this morning. The nose cone needs a gasket of the thin paper type where it goes onto the gearbox, so I cleaned it from all grease and oil and put it inside the scanner, face down



If you scan it at 100 dpi, you get an exact 1:1 representation of the shape of the nose cone, it can now be printed on thin carton, and you know exactly where to cut it to make the perfect gasket



I have now seen for the first time the exact position of the breathing hole of a gearbox (yellow arrow). The red arrow is the cavity that the air follows to escape the gearbox. Other than the little hole, the rest of the box is perfectly sealed. Serious off-road races cut a thread in the breathing hole, and attach a pipe to it that goes to the air filter, in order to prevent water from entering the gearbox during river-crossing. I don't think dust entering the gearbox will ever be a big problem, as air will theoretically always be flowing 'out' of the gearbox when the gears are moving?

And where does the new 'fresh air' come in Pine???

Hmmmmm - haven't figured that out yet