904 Clutchflite

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Bakerlite

Bakerlite

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How's it look so far?



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External pump on this one because I want to use a diaphragm pressure plate. I'll size out and de-tune a small power steer pump. The front half of the old pump housing will be replaced with a piece of alloy plate that will contain the input shaft roller bearing and bolt on support housing for the hydraulic throw out bearing. This will allow me to block off any pressure passages I don't need and machine in the ones I do need. Pump pressure connections will also be added to the plate.
I'm going to use the old manual trans input shaft and the old 904 input shaft to splice together into the new shaft. I'll then fit this shaft to the box to make sure it works as it should and has no leakage issues etc. I'll run the trans on my test bed with a small amount of load. Once I'm happy with the results I'll pull the test shaft out and have a new hardened one piece shaft made..
 
Some more done,shafts cut and pinned,just have to double check the new input shaft length before I cut the bar stock down and fit it between the old shafts. I have made a small dummy insert so I can check the shaft length. Also have some 12mm alloy plate to make the new front section of the pump casing and bearing retainer.
Mark on the tape is where I think the mounting face of the bellhousing lines up to, about 31 mm ( just over 1.220 inch ) protrudes out of that into the crank support bearing. I'll double check that before final cutting.
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Shafted!!! Next is to true and weld it. Plate ready to make front half of old pump housing.
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ok,so not real versed on this idea. You disengage the clutch and in effect you shift from 1st to 2nd then 3rd with 100% power transfer. Good luck with the shafts holding up on that 904.
Interesting idea though.
 
I'm not worried about the input shaft, as you can see, it will end up thicker than the original.Springs in the clutch friction plate will adsorb some of the shock of the gear changes, as well as not going berserk with the valve body and shift pressures. When I get the new shaft made I'll be dropping into a another shop to see about maybe getting a custom plate made with better springs, if need be.
 
the output shaft would be my area of concern on what would be considered a locked 1-2, 2-3 shift. Right around the thinnest part at the front planetary.
 
FredS said:
the output shaft would be my area of concern on what would be considered a locked 1-2, 2-3 shift. Right around the thinnest part at the front planetary.
Click to expand...
I think you just need to have a little more faith in the old 904. :) If I worried about everything I built breaking, then nothing would ever get built.
 
My clutchflight shifts just like a auto and you do not have to touch the clutch pedal to shift manually.The clutch is only for stoping and starting.But you are right about the out put shaft broke a few and a lot rears and axles.
 
Well yeah...it's still an automatic, unless you go manual valve body so it would naturally still shift. lol
 
Not my concern,merely an observation from what is likely to give out first. What kind of power you planning to put through it?
 
Freds ask if you had to used the clutch to shift manually from 1 to 2 to 3 and no you do not
 
not at all jockeyshift. I understand the concept, but applied to a 904 vs a 727, it raises questions about parts breakage, primarily that output shaft right past the splines where the front planetary rides. Locked shifts(which in effect this mimics like an applied clutch in a converter) with any kind of power/torque applied and any firmness in the actual shift will take out that shaft.
 
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