Electric Valve Body Prototype

ABOUT A YEAR AGO I WAS TOYING AROUND WITH THE CONCEPT OF A PUSH BUTTON TH400 TRANSMISSION WITH NO SHIFTER LINKAGE SO THE FLOOR COULD REMAIN IN ONE PIECE. I NEVER DEVELOPED IT. LOST INTEREST. HERE ARE MY FOOTNOTES FROM THE PROJECT.

11-25-2012

old design for 1st/reverse only

line pressure constant to the rear band then control psi to the direct and forward clutch assemblies . maintain direct/reverse clutch bleed to apply via a controlled orifice in the set crew in the center support. forward is un-metered. the valve to do the job was tentatively found and available for 150 bucks. system pressure still dictated by front pump modifications and at this point not impede system opressure to cooler or converter/lube circuits.

1/2 inch steel plate with 1/4″ pipe tapping will replace the valve body with 4 lines to a hydraulic control valve. this would be line in-forward-reverse-and bleed to sump. open center valve. this would work to eliminate shifter but leave 4 hydraulic lines….actually 6 hydraulic lines to rupture causing not only a routing issue but a safety hazzard.

it was built never finished. wasn’t right. new design concept:

i need electric over hydraulic.  base design using 4L60 or 4L80 technology is more desireable. accessable parts and solenoids. i think we can keep the constant flow to the rear band for 1st/reverse hold and use the two prong plug off the older th400 kickdown. one would be used for forward and one for reverse triggering. obviously neutral would be no power but fluid would still flow to the rear band via line pressure. free flow of clutches to sump while line is blocked off completely. this would be better as if i went open center with old design i may lose all system pressure bypassing the regulator feeding everything else to converter-cooler-lubricating. so we need  two triggering solenoids to that both deadhead line psi when not engaged and vent the clutch pack.

basically we are looking at a custom valve body out of aluminum with two spool valves- fed by line pressure and allowed to vent to sump off the clutch pack when dissengaged. each valve would have independent constant pressure from the control line off the regulator. when energized the vent port would close and line pressure sent to that clutch pack. when de-energized a spring would return the valve to vent the clutch fluid as well and block off the line psi to maintain system pressure.

so what we are looking at is two spool valves most likely normally closed to line psi while maintaining vent to the clutches. basic two power wires out the transmission and system is grounded through the case/chassis. when energized it engages a clutch. all shift controlling would be done externally this would cut cost and simplify the routing of wiring to trigger the car.

to prevent multiple clutch lock up we could use an industrial controller which automatically dissengages one power while engaging the other, and leave a toggle switch for neutral next to the two place switch. basically and arming switch. possibly have a solenoid to hit and dissengage park next to the arming switch. either way i think a two place switch is the way to go either forward or reverse no neutral. simplfy the shift and leave neutral or park separate. therefore eliminating false shift

looking at if i am thinking 2 inch thick aluminum with a custom 4-6 inch deep pan. i am thinkin either no filter or a custom filter “sock” of some kind. no paper element.

grove on the line psi side  toward the right of the diagram for supply, then cut the port to the left side supplying fluid to a trigger over the direct-reverse passage and following through to the rear servo. the forward clutch valve/trigger oil/spool is a different story. being at the front i can either run it sideways over the old rooster head manual shift area of replumb it to the rear next to the reverse spool.

here again we leave some kind of solenoid to trigger a park or abandon it all together, which is not an option to me. overall the valve body is only concerned with 1 supply line-1 constant supply while running- and two control ports. if we need a second gear it would be three ports and there is a possibility of using two solenoids both energized to create a 2nd gear shift via spool valving, but it is over complex and unnecessary at this point.

so at this point i have the concept but i need to figure out the valving and the solenoids. we are going with an aluminum plate for the control body for sure. re-examine gm electric tranny stuff i think would be the way to go. if we can find an existing valve to use and simply use one part of both. also could we use i long valve on one solenoid to move it forward after armed and energize solenoid for reverse. forward being the stronger end of the car in failure AND stronger circuit for the most part. even in this design we would need a separate arming solenoid to dissengage the tranny but would be a simple circuit such as a TCC circuit in comparison to the rest. this would leave one valve for machining reducing cost.

if we do two inch thick we can tier the passages, however 1″ with one valve also simplifies cost and machining as well. we have a cost factor. so we do a static passage to the rear servo-to supply one valve. no energized we got forward/reverse energized. a second valve would have to vent and deadhead line psi. either we use two control valves of 1 control valve and one arming valve. it would be left up to a cost issue.

the overall goal is a 1 or 2 wire control valve body on the existing design of th400 1st/reverse only. possibly an upgrade for existing trannys.

it appears that the modern solenoids control the oil flow via an internal pintle on the valve on the solenoid to move the main valve to trigger shift. this adds a layer of complexity. we will be looking at an oil tolerant valve from the old design to go into the pan. these exist in an industrial enviroment. engineering two oil circuits to accomplish one goal is ridiculous. i am thinkin two valves-oil tolerant externally to go in the pan, leave the valve body in the air. more research but not abandoned. this is neat!

11-26-2012

after a day or research, the older design seems more practical than i thought before for both cost AND perception because it is a visual difference AND mechanical may sell moreso over than an electrical design. i believe i can use a 1/4″/-4an metal braid line with the modified log splitter valve as before. i would use a two piece oil pan with a drop out center plate so i can fab the lines to the steel plate. the original had brass fittings they may be swapped for steel, welded, then faced on a lapping machine for proper seal to the case. omit the oil filter and tap the oil pick up and modify a chevy engine pick-up to weld to the tapped case pump pick-up tube.

the electrical design is not abandoned. i think the proven product and method to do this would be a custom aluminum valve body with milled passages and drilled for two spool valves. a mid plate is a definite in this design to isolate the passages. i would use two solenoids out of a 4L60E. i believe these fire an oil charge at a valve to create shift. i think if i can use an existing valve out of either a 4L60E of 4L80E then mill the aluminum to fit the passages it would be the most cost effective. exhaust each out the top(bottom to sump)/ deadhead pressure when not in use to line. basically two 3-way spool valves. as for an arming switch it would be nice to have a switch to arm the panel and dissengage park. a biondo type solenoid to go in and out of park would be ideal. so when you arm the panel it energizes to dissengage park while arming two switches for forward/reverse. this would require a 3 wire plug though. it would be much simpler to omit the park but it is a liability concern. perhaps a pinion brake with a park pin is a better option or a pin engagement to a nerat yoke.

 

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