Is there any interest in a group buy for 411/412 manual transmission upgrades?
* New counter shaft
* New Torlon counter shaft bushings
This is an important rebuild to keep your stick shifting
I'm moving ahead with getting material and machine work done to make the replacement shaft and custom bushings. Is anyone interested in getting a set at the same time? Price will be about $200, depending on volume. Let me know by 3/15 if you want in.
i think its excellent to replace the shaft. If you are sticking with stock needles...its required.
Just bear in mind...and sorry I didn't let you know earlier...but from the pictures...your original shaft is smooth enough to reuse....if you use Torlon bearings. It will soon be ugly with needle bearings....but Torlon has such low friction it will be no problem if you want to save money. Ray
The counter shaft s not too bad. The easest way I have found is to buy linear bearing rail from Mcmaster Carr ro soemplace like that. Its tolerance isexcellent, its very hard, very straight and polished almost to the level you need. The rest can be done with 2000 grit.
The hardest part of that....is finding a machine shop that has a grinder attachment for their lathe. What that does.....is to chuck teh shaft up between two live centers ....and has a grinder attachment that can grind to specific depth. This is actually pretty common tool....but you just have to ask around. One hole drilled...one step ground...done. Ray
I have another working tranny and if that goes bad I probably will transplant some other (probably porsche) transmission in there as I probably want more hp than the original tranny can handle anyways
Thanks for the invitation anyways,
Walter
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi www.apfelbeck.nl "Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
Either a 915 or G50 short-nose. I am sure you know what you see here Look how the slave cylinders are in the same location
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi www.apfelbeck.nl "Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
Wow, the 004 rebuild thread is awesome, I don't know if I have the patience for something like that? I definitely don't have the facilities or money right now to do any transaxle rebuilds- buying a house! Should have room to build a nice shop out back and then I'll be back in the 412 action again! Besides the ones in cars, I have 3 spare 004 transaxles, so I have plenty of work cut out for me...
Yes...you have teh patience...and the tools are not that bad at all. This is partly due to two things. (a) The 004 is quite unique in that except for setting up the differential....there is very little real set up work to do compared o any other ACVW. The design of this transaxle ...especially in the main gear section...is such that all spacing and dimensions are set up to the actual case dimensions from the factory.
They are pre-shimmed....these shims are on the counter gear cluster and the shim between 3rd and 4th gear on the mainshaft.
The only time you need to adjsut these are when you actually change gears out for new ones......which you will not find.
If you change one set to another...simply measure the shims that came with the donor gear set...compare to the old....and make up the difference.
As long as you keep all the parts together....all you need to make up for is wear to shims gnerally.
The Synchros....are a problem. Its the hubs that wear...not the rings. But I am experimenting with back-shimming the rings to give the same operative float range relative to the hubs...to restore operation.
Wally...I remember the 901 thread now. I think taht would be a great swap for this car. Ray
(b) This transaxle can be stripped with hand tools in an hour or so.
Hey Bill K., do you think after your rebuild that you would be able to repeat the process more easily? Why I asked is maybe vs. a parts group buy you could offer rebuilding and upgrading for those who don't think they have the abilities to do that kind of job? I guess the group buy would be good for those who couldn't do the work but would then have the parts available and procedure to bring to a tranny shop.... What do you think a tranny rebuild kit of parts would cost in a group buy? Bill
Yes Bill, the rebuild will go much faster the second time. I can see it being done in an hour as Ray claims if the process is committed to memory and one is well organized. It's taken me many times that interpreting Ray's instructions, finding the right tools, and photographing the process. I do plan on doing a second tranny once I install the first rebuild.
I offered the group buy for those interested in doing their own tranny and wanting to get a deal on custom part design and fabrication. Now that I know my countershaft is reusable and all that will be needed is Torlon bushings, the idea of a group buy may be less appealing. However, Torlon and small lots of custom machined parts are fairly expensive and others wanting to do a rebuild may benefit from a group buy (realizing the design is not OEM VW or road-tested). The remainder of the parts needed to do a "kit" are standard and would not save you more than a little shipping.
As far as rebuilding services, I'll leave that to the pro's. I just drive my hobby.
The idea is still valid imo and if the investment is not extremely big, I would still be in and support the group buy of the special parts, just in case I keep the power outputs down.
The original tranny still fits better and a 915 rebuilt is surely more expensive.
Never thought you could open the 412 tranny and close it again these days
(which reminds me, I still need to ask about certain shipping costs of injectors )
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi www.apfelbeck.nl "Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
This is not to say that there is not a lot of tolerances that would needto be checked in these transmission. They can...eventually.... suffer from the same things as other ACVW trannys.
Things like worn detents and worn shift rail bores in the case. But....they rarely seem to have this issue. In my mind...the idea is to find one in good shape....correct the obvious flaws....take care of it and set everything back to original tolerance....and drive it.
There are so many things we cannot get for this tranny. I'll list some.
The seal on the tail cone shift rod. What I do...is pull out the old seal leaving the brass bushing intact. I then clean everything perfectly clean. Since I can't buy the original size seal...I can find one smaller with the same size ID. I install it and epoxy it...done.
There are some critical tolerances. When looking at the main gear stack....on the pinion main shaft.....there is a thick spacer right in the middle. This was used to set up the spacing of the main pairs of synchro/gear clusters......in reference to the case (the case section with the lid on it).
From there...the counter cluster was placed in....and there were several sizes of paired end shims...that placed the counter shaft into the case....with acceptable tolerance...when new. Once things wear into each other.....they are set for life. The only thing to be careful of is that nothing seriuously wears...or you do not install case gaskets that bring teh main shaft shims out of tolerance to the case.
The detents....if the "bullets" are worn....I make new ones. Its just not that hard to do...and since they are servicable from the outside...its easy to change them when they wear. Since I make them of unhardened steel.....the shafts will not wear out.
I probably should beexplaining this in the main post...but here goes. We can always move it.
When you were disassembling teh tranny...you found a snap ring on the outside of the main ball bearing that did not belong there.
It was being used as a spacer. It is the right thing to do. The problem is....and this is a flaw....as the case ages...the bearing bore gets loose and it is deeper than need be. In that case the bearing slips outward....bring the synchro hub attached to it out of correct spacing to teh baulk ring...makingshifting hard. I use spacers as well to bring the bearing up hard against the inside circlip.
The main snap ring that holds the gear sets in place on the main shaft...only gets loose for a couple reasons (1)if the center spacer shim on teh mainshaft between synchro sets gets worn heavily. Its very rare. Usually though you can see one edge in the center that has had no bearing contact ...from which you can measure the true thickness if you need to replace it. (2) if the synchro hubs get heavily worn.
I will explain more about the synchro hubs in the main rebuild post. Ray
Look how the slave cylinders are in the same location 
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