47RH shifting with pressure switches

slrrls

slrrls

Water fuel 1st diesel 2nd
Joined
Jun 30, 2012
Messages
135
Have been driving the 99.5 with a 12 valve and a 47RH for about 5 years.
This was the thread where it began. If anyone has questions on how to set it up then just read the following thread from front to back first and you'll learn what to do.
http://www.competitiondiesel.com/forums/showthread.php?t=137386

I'm trying to sweeten the shifting now.
I have the two pressure switches coming off a The rear servo test port. They come off and then T so both pressure switches are working on just the rear servo pressure port.

I see it as a problem that I can't get the two pressure switches isolated on their own switch.
There is a toggle for both switches to work in an automatic mode that works properly.
-Then a toggle to switch the overdrive on which when I switch it both switches activate at their set pressure to come on.
-Then another toggle to turn on just the Lock Up but when I switch it both pressure switches turn on a their set speed.
The only thing I can think that is hindering just one switch working on it's own toggle is that I have the pressure switches on on test port connected to a T.
So when I actuate one somehow the pressure transfers through the T and actuates the other switch as well.

The question puzzling me is if it is ok to connect one pressure switch to the Governor test port and one swich to the rear servo test port or one of the other ports so both are isolated?
And has anyone else seen this problem and what did you do to solve it?
I'm also wondering if I could get the 99.5 trucks transmission pcm to shift the overdrive for me? Then I would only need to put the Lock up on a pressure switch and toggle. If that is possible then what Pin would I need to choose?
I even wonder if I could run the lock up from the 99.5 computer on 54 as in this diagram?
http://www.tstproducts.com/Torque%20Converter%20Lockup%20Switch.pdf
 

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I hate when I get busted talking to myself but does anyone have a clue if we can use two test ports for pressure switches on the 47rh?
Or maybe somebody could pitch in what each port does and how critical they are in the mechanics? I'm not quite knowledgeable about transmissions yet.
Anybody???
Buhler?????
 
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Google search the test port pressures and when they start reading pressure - the rear servo would not be good. Probably the governor and accumulator ports. I'm guessing though.
 
ah-HA! good example of can't see the forest for the trees.
http://www.cumminsforum.com/forum/94-98-powertrain/321085-47rh-test-port-pressures-help-would-geatly-appreaciated.html

pag01.jpg

since there is an OD test port then it seems like that would be a proper spot to connect a OD pressure switch?
 
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Reading the accumulator port I read it that the port would not show any pressure until 55-60 psi at idle and 90 to 100 psi at WOT.
Am I correct that In the above chart there will not be any pressure on the test port until the given psi pressures are reached?

And thanks for that Schmitty I'm going to use the accumulator and see how she does. That should also solve my leaking from the port problem.
 
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im assuming overdrive only sees pressure when it's turned on.
 
After installing the pressure switch on the accumulator port the wires and the switch is only a half inch or less from the exhaust pipe and I'm considering it may get the wires or switch too hot while at idle during hot summers.

Do you suppose putting the overdrive pressure switch on the overdrive test port would work properly and not cause any problems?
 
I don't have time to read this until later, and speed based switches need to all be attached to the governor port.

The function can be selected by a switch, one path to ground, the other to the pressure switch, then ground.


Sent from my Moto X using Tapatalk
 
OK, I read the thread. The only port you need to connect your switches to it the governor pressure port. It is directly proportional to wheel speed at all times. The other ports, especially some mentioned, will only apply significant pressure when those circuits are active/applied.

For instance, if you install a switch in the Overdrive port, with no other electronic control, Overdrive will never occur. Something would have to raise the pressure of the OD hydraulic circuit first, before the switch would change position.

T them both to the governor pressure port.

To address your clearance question, go to Napa and buy a grease hose for a grease gun. If you pry a little, you can get the hoses in any length you want. You can attach your switches somewhere else at that point.

You could use rocker (single pole double throw? ) switches to allow the pressure switches to close (automatic function) or take the other pole of each switch to ground and manually engage the TCC and OD.

Sent from my Moto X using Tapatalk
 
biggy238 said:
OK, I read the thread. The only port you need to connect your switches to it the governor pressure port. It is directly proportional to wheel speed at all times. The other ports, especially some mentioned, will only apply significant pressure when those circuits are active/applied.
Click to expand...

Thanks, I'll look into the grease gun hose.
 
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