I therefore started to read up extensively on the Type 4 and was drawn to an American forum could shoptalkforum. A lot of the info was and is very technical and often way above my head but I learnt that these cars are all prone to suffering from this defect. I think VW would have eventually engineered it out but as the Type only had a relatively short production run they never got around to it, maybe that is so maybe not. Who knows?
The more I read the more I was certain that the front end of my 412 was failing. As winter drew near my front struts started to make a horrid noise as the water that was in them froze. Something had to be done. I didn't want to go down the route of trying to find second hand repalcements that probably wouldn't last long and the thought of NOS ones that had languished on a shelf for 20-30 years didn't appeal either.
I therefore contacted a certain Ray Greenwood, for those who don't know he is one of the American fonts of knowledge for these cars, and asked for details on the front end rebuild he suggested that the Type 4 needed due to design flaws in the use of materials by VW.
With the help of a local garage I set about the rebuild sourcing the needed parts to change the front inserts, strut tops, track control arm bushes, centering rings for radius arm, lower ball joints, bronze steering idler bush and anti roll bar bushes.
Unfortunatly I seem to have lost all the required measurements for machining the extension for the strut insert but I will endeavor to share what I can. The front insert of choice for the 411/412, as the originals are no longer available, are from a mid 80s Audi 80 (KYB 365008). Apparently Ray spent a lot of time experimenting with a wide variety of shocks to find one that would have the same valving characteristics of the original which would therefore not destroy the lower ball joints. The theory being that this was more important than the dimension of the insert as they could be adapted to fit.
As such these inserts are too short, both in the length of the body and the length of the piston (shiney bit that goes in and out). To make the strut fit requires an adapter to be machined out of tool grade steel that screw on to the top of the insert that makes it about 3-4" longer. A spacer also needs to be put into the bottom of the strut body to enable the Audi insert to seat into the VW strut. The stub extender was desigend to screw onto the top of the Audi insert with a shoulder that overlapped the top of the Audi insert to ensure a good strong joint, you can just about see it in the picture below. (There seems to be an ongoing topic on the shoptalkforum that includes the measurements http://www.shoptalkforums.com/viewtopic ... 0&start=30 although I can't vouch for the accuracy of herr-sparky's work you should be able to get the idea of what is needed).
Once the strut was completed it was time to sort the strut top. The early Type 4s all used a 3 bolt configuation spaced at 120 degrees to hold the strut tops and used a bonded rubber bush that is prone to splitting and failing. Later Type 4s used the same strut tops as the superbeetle fitted with McPhearson struts so this is what I converted mine to use. This requires new holes being drilled to accomadate the different bolt configuration and the centre hole boring out a tad, again this is evident in the below picture which also shows a superbeetle strut brace fitted without any mods.
From memory I think we had to play around a bit with the spacers required to ensure the top of the struts rotated freely but I can't recall exactly what we did, however if you take the time to read the above link some of these qusetions are answered complete with advice on using an improved strut bearing from a Mazda. I didn't do this but might look at it in the future.
The bushes in the track control arm where perished so had to be replaced. On doing more research it became clear that these are another item you can't buy new so we had some made up from a plastic material known as Delrin. This new bush took the form of two top hats that would fit around the original steel sleeve from the old rubber bush which could then be inserted into either side of the arm like so
The same material was used to make up the centering ring for the radius arm.
My anti roll bar mounting bushes no longer seemed to hold the bar as they should so were replaced with some from a Mk2 Golf
The Type 4 idler arm bush was originally made from rubber and was another weak link in the front components and contributes to the 'wobble' so this was relaced with a bronze one that was machined to fit as I could not find a super beetle bronze replacement for love nor money.
One other job that I should have done was to replace the nylon bushes in the centre tie rod with bronze bushes but a lack of funds and time pressure meant I had to skip this one as we needed the car back to go on holiday
, I have since acquired a spare one that I intend to modify soon and swap this out. Again more info can be found on the American forum.One other thing I did was to repalce the rear shocks with some gas ones from the front of a Ford Econline 3/4 tonne van. These made the rear a little firmer and match the handling form the front end very well. The only difference to the fit is a small stack of washers either side of the lower mount.
The wobble had gone and the car drove and handled far much better with the added bonus of dropping the nose to make the car sit more or less level.
I have subsequently read on a number of forums that the front springs from a BMW 320 (E30) will fit and lower the nose a tad further without being detrimental to the lower ball joints.
I'm sorry I can't help with the measurements but if they turn up I'll gladly forward the specs to anyone who is interested.
In the meantime I'll continue to search for any part numbers that may be of use...curse this modern technology that insist on hiding these details from me
