Engine/Transmission (1994 - 1998) 47rh and 47re vb the same??

[mjoppie]

i kinda need to know if a 47re and a 47rh valve body is the same, or will work in each other. i have a good gorends vb for a 47re and just bought a 95 diesel and want to put it in it tomarrow. my 98 is turning into a off road toy and getting a stick. so i bought this 95 for cheap and it wont go into overdrive, so i figured i would try the vb while i had some time on sunday. the trans shops are closed so i cant call anybody. thanks a bunch guys





matt

 

[SEmerson]

no very differnt

 

[mjoppie]

dang!!#@$%! i was hoping. what would cause it not to go into overdrive?? is there a way i could bypass the temp sensor to check that??

 

[Joe G.]

Pull the connector off the temp sensor. Get a 1K resistor. Put the leads of the resistor in the connector pin sockets. That causes the PCM to react as if the transmission is warm.

 

[mjoppie]

thanks a bunch Oo. i will try that in the morning. anything else i could check for? i tried grounding one of the wires to make it go to overdrive but it didnt work. im gonna try a different ground to be sure tomarrow. would it be the solenoid on the transmission that has the magnetic balls in it?? i picked it up for cheap and just plan on using it as a work truck that some guys are going to beat on so i dont want to have a bunch invested. i wanted to do a converter and vb upgrade but i would like to figure out the od problem first.

 

[TBurow]

try swapping the od/ tcc solenoid from the other vb, if i remember right all you will have to do is splice the wires together so you can use the 95 plug

 

[mjoppie]

where is the od tcc solenoid at?? is that the one with three prongs between the two magnetic solenoids?and will the wires be the same color?

 

[Howard Durand]

Both the OD solenoid and the TC solenoid are on a bracket mounted on the valve body. If you want to check them for continuity, unplug the main connector at the PCM and connect an ohm meter between pin 54 and ground then check between pin 55 and ground. They should each indicate about 30 ohms. Pin 54 is for the TC solenoid, pin 55 is for overdrive.

Connect the meter to both pins and you should have about 60 ohms.

You could do this at the transmision but it is easier to see what you are doing this way.

The third wire in the cable at the transmission provides the 12 volts for operation and is energized when the ignition key is on. All the PCM does is switch the ground leg.

 

[mjoppie]

ok, i will try to get a ohm meter today. ive been trying to install a tc lockup switch but cant find out how to on this 95. i did one on my 98 and it works fine, but there is no trans relay in this 95 and im not 100% sure i hooked the right wire in the pcm. when i drive down the road its always locking and unlocking. it already revs over 2k so i would like it to stay locked.

 

[Howard Durand]

I think the pin numbers for the TC/OD wiring are the same for both the 94 and 95. Not sure about anything after that.

 

[mjoppie]

im picking up a ohm tester this weekend and hopefully thats the problem. it shifts great from 1st-3rd but no overdrive. i can fix that one for $50. thanks for all the help, i will repost all my findings.





matt

 

[ttammeslehto]

mjoppie, what was the reason for the no overdrive, I have a friend with -95 and similar problems, he has changed the solenoids, temp sensor but still no od.

Timo

 

[Howard Durand]

With the 94 and 95 transmissions, the shift into overdrive is controlled by a signal from the Throttle Position Sensor to the PCM. This signal is nothing more than a dc voltage that ideally varies in magnitude between 1 and 3 volts as the accelerator pedal is advanced. If the overdrive solenoid and the mechanical device in the transmission is believed to be functional but it still won't shift, it would most likely be a lack of signal from the TPS. Even with an erratic signal OD should engage at some point of throttle advance. You may also want to make sure there is no problem with the "OD Off" circuit.



You can use a voltmeter to test the TPS to see if it is functioning. Stick a pin through the orange center wire at the TPS plug. Connect the positive lead of the voltmeter to the pin and the other to ground. Turn on ignition and you should have a voltage of about 1 volt. It could be more or less but not much.

As you advance the throttle the voltage should rise to around 3 volts at full throttle.

If you don't have any voltage on the center pin, try the violet wire with the white tracer. You should have 5 volts.

The black wire with light blue tracer is the ground wire.

If you have 5 volts at the violet wire but nothing on the orange wire, the TPS is bad. If so, you may want to spend a cople of hundred bucks for a new TPS or ten dollars or so for a better solution.

Do a search on TPS replacement for more information along that line.

 

[sdstriper]

Matt, do a search on potentiometer. I would do that mod before I spent one cent on a TPS.



Howard, is that what you were getting at?

 

[Howard Durand]

That is what I am referring to. I am using the potentiometer in my 94 and I'll never hook up the TPS again.

So far the only drawback to the pot is loss of throttle "kickdown" for unlocking the TC but you can do the same thing by tapping the brake pedal.



I am using a potentiometer but I am making up one that uses a rotary switch and some resistors to accomplish the same thing.

The potentiometer I am using, and like real well, takes 10 full turns to cover it's range of resistance. It is good because it gives better control than a single turn pot.

The rotary switch can duplicate the selectivity of the multi-turn potentiometer in a single rotation of the knob.

Also, it is less expensive and simpler to build because it eliminates the need for a turns-counting dial for the multi turn potentiometer.



One of these can easily be made up with enough 3 wire cable to reach the location of the TPS. There are plated pins available that can be soldered to the end of each wire. Then all you have to do is unplug the cable from the TPS and insert the end of each wire into it. That would eliminate the need to cut into the existing cable.