this is the subframe removed from the car. its fastened to the body with three large bolts that screw into special captured nuts that are in a slotted recess to allow for camber/castor adjustment. they were so heavily rusted in place that it took me several hours to get all three out. the control arms will get new bushings and the radius arms new donuts. theres also rubber centering rings that should be replaced with urethane and various other bushings that need replacement/modification. a member of the 411/412 forum has a great website detailing this whole process here
the center nut that holds the strut assembly together requires a special tool to keep the damper shaft from rotating with it... i got lucky and found a socket i had modified for some other project that was the right size and even had some knurling on it for my pipe wrench to grip:
once everything was apart it was obvious that it had been tinkered with by someone else before; there was a very curious mixture of washers in the wrong places...
here you can see the factory bump stop bushing and just above it a stack of aluminum crush washers... they had been hammered flat from years of driving, and just above them was a split lock washer... its sharp edge had dug into the face of the upper spring plate... wha the?
possibly the strangest thing i've found is that the distance between the spring seats when the strut is fully assembled (but not mounted in the car, of course) is about 10 7/8"... lets just call that 11" for comparison. the actual coil, when removed from the strut assembly, measures roughly 18" at its extremeties...thats a whopping 7" of preload when assembled, nearly half its entire length! in fact, it was more than my spring compressor could handle; i ran out of threads before the coil was totally relaxed and had to sit on it using a spare brake rotor as a seat to relieve the last bit of tension on the tool just so i could remove it:
its hard to believe that that kind of pre-compression is what VW intended (or anyone for that matter...) but i cant find any specs anywhere to (dis)prove it, and the 411/412 forum has been a dead end for good information for a couple weeks now. its too bad that internet forums always work out like that...a great place for self-righteous bickering but when it comes to hard data its kind of a wash. so i will just figure it out myself and make my own mistakes (the best kind)...
so now that everything is disassembled i can make all my measurements and try to design my own adaptors/bushings. i'm still inclined to use the Mazda bearing, and i already have the new Super Beetle mounts, but i dont have a suitable bump stop arrangement... using the Mazda bearing with a bored-out spring plate will eliminate the factory bump stop bushing/spacer as the bare damper shaft passes directly through them and its shoulder rests against the main strut bearing in the mount instead of the bump stop bushing. that means i need to find either a generic or OEM bump stop w/mount that fits the bare 22mm damper shaft, maybe even the Mazda 626 part, but i cant seem to find a good exploded diagram to study...
