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Will Super Beetle strut cartridges work in my '71 411? I've got to figure out something for my front end!!!

Hey, this is one of the previous Post with replies. Ray gives a lot of great info in the replies! Thanks again "Ray"! Hope this can help you? Bill

VW412 Strut problems?
I am having a problem with the struts on my 412. After installing a NOS pair of Boge gas charged struts (#411-412-031H)they are clunking at the bottom of the stroke and at the top of the stroke as the suspension travels up and down. The car is a 05/73 production and the front end is all new including the ball joints. Is this strut correct for this production date or could it be something more simple that I am overlooking? Any help would be appreciated.

The part # I think you shoul have...is the 411 412 031 M. Question: do your strut bearing mounts have 3 bolts that are spaced asymmetrically..meaning two basically toward the rear...and one closer to the front? If so, you probably have strut cartridges from 411 and early 412 in there. The difference is a pair of 13-15mm spacer rings to make the bump stop and collar fit correctly. There was a chassis# change for the correct strut. If the person who sold you the struts did not ask your chassis #...they are probably wrong...but can be fixed. Also, if every thing is correct...and you sstill get this problem...a) did you put in the centering rings...b) did you put back in aqll of thespacers and washers correctly...c) did you torque the top nut all the way down...d) there is also the possibility that the cartridges are shot. If they are Boge...they have been on the shelf for over a decade. Thats how long its been since last production. The last set I had of Boge that were NOS...lasted 50 miles. The seals go flat when they lay around. No reflection on the manufacturer...just old. Contact me here if you need some options on replaing cartridges. Ray
It is the symmetrical, i.e later type, and we are pretty sure the NOS Boges are bad from age. Other than the extremely expensive KONI replacements, is there any other cartridge being made by another manufacturer or for another model that can be adapted to fit without too much expense?
Ray, after further study, the Boge cartridge is working ok, but it appears that it requires the "spacer ring" as the entire cartridge has about 1/2 of an inch to much travel in it with the nut fully tightened. This spacer was not on the hydraulic cartridges that I removed and was not included with the Boge units. This spacer ring is shown on the cartridge piston in two places in my manual and looks like a machined washer with a step in it. I imagine this part is scarcely available since the struts themselves are impossible to find. The Koni's I mentioned in my earlier post are themselves NOS that were manufactured in the 1970's and are probably too old to last long in use. These Boges will probably not hold long either but right now they are all we have. Any thoughts, ideas, or wild *** guesses appreciated.
A few notes. There were actually 3 strut bearings used in the type 4. 1) was symmetrically spaced bonded bushing with a plane type friction bearing (no ball bearing). Those were not shipped. That was like 68-70. 2) Symmetrcal spaced bonded bushing with swaged in ball bearing. This was common until about Jan of 74. 3) assymetrical non bonded ushing. This is the same one as the late superbeetle. It has a black or white nylon spacer ring at the top and a replaceable rubber insert bushing and seperate ball bearing assembly. What I mean by symetrical is the spacing f the bushing plate attachment bolts. In the 1st two models they were spaced at 120 degree. If you have those, it wouldpay you to sooner or later get rid of them and drill the extra hole it takes to install the later ones. The only good bushings for the early symmetrical one I have found are about $80 each and old when you buy them. New bushings and bearings for the superbeetle style are about $24 for bushing and bearing.
The metal sleeve you need has no steps cut in it. It actually fits in the step on the early shaft. It is about 5/8" long, is 14mm id and 22mm od...actually about 21.5. It is just slightly smaller than the shaft. You can use metric drill collar or arbor bushings from a tool supply. Even a split shaft locking colar without the bolt in will work. Its just a spacer. A stack of the right size washers will also work.
Be etremely careful here. Koni has never manufactured parts for the 411/412. They may...by dimensions..be able to find you a shock that FITS, but if the valving is not correct...it will destroy the front end in very short time.
The problem is that the 411/412 was designed with a very large trunk. It was designed to be a travel car. The length of the struts and the spring loading were designed around the thought that most of the time. the trunk would be full. The weak link in the original strut valving is not the compression direction (down-stroke. It is the rebound...or up-stroke. The springs on the front end are actually heavily oversized. They are ...like most Mcpherson struts...90% of the suspension. The rebound was designed to be damped by trunk weight. The high spring rate literally ends up destroying the strut cartridges in a lightly loaded front end . If you got some by Koni...that fit...chances are the valving would be so tight that it will quickly destroy your ball joints. You cannot use high pressure gas on the front end of a 412..only oil or low pressure gas like the KYB gr2. The front end is arrested too quickly on the downstroke by to highly valved shocks. They cannot compress fast enough because the load is too light...so they transfer the enertia to the compression spring inside of the ball joint...beating it to death.
The almost perfect valving I have found to be in KYB GR2 strut cartridges for an Audi 4000But...the body of the cartridge is too short...and the top stub too short. What I did was have a pair of stubs for the top machined. I will set up the drawing of them for E-mail in the next few days. The top 3/8" of the new Audi strut cartridge where you put your wrench to hold the shaft still will have to be cut off. The stub screws down and bottoms out. The set screw and locktite complete the job. It allows stock spring compression distance to be used, as well as stock strut bearing and bump stop.It also is set up to drop the front end about 3/4" to make it level with the rear. t gets rid of the nose high attitude and improves the static castor by almost a degree. The handling with this set up is stupendous.. You will need a spacer in the bottom of the strut housing of about 2". The best way to make one is to cut off about two inches of your old strut cartridge at the bottom and drop in there. I have not re-published this yet, because I have found what I think is a better way. I have been running the stub method for over two years. But...a better way is to take an old pair of 411/412 or superbeetle strut housings...and lop off the top threaded end where the cap screws on...at the length of extension you will need. Take it to a machine shop...put it on a lathe...and have the cut end threaded on the inside, to screw on to your strut housing in place of the cap. If you are worried, you can use a set screw or a single spot weld to keep it from unscrewing. You wil need about a 5" spacer in the bottom of the housing. You will have to use the late model strut bushings (assymettrical) and an after market bump stop with boot (golf or fox will be great). This is way simpler...and much cheaper. The Audi cartridge has plenty of travel. The stock type 4 cartridge uses less than 7" of the travel it has. I cut open about 50 different cartridges in the junk yard over two years to find out what had valving very close to what the 412 needs. Ray


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