Engine/Transmission (1994 - 1998) 47RH How does it work?

[Slaughter]

I am trying to find out how the 47RH picks its shift points. I understand that it is done by Hydraulic Modulation in the first 3 gears and by PCM for OD and Lock up. How can these be tweaked? Can it be made to shift with out TPS or other computers? I'd be willing to rig some switches up to run a few things it I have too. Just finding out how it functions is a pain, I can find all sorts of GM/Ford BS to read but not much Mopar. I tried a slightly different post in Conversions, without much luck. If I can find out how the darned thing works, or if a cheaper factory transmission manual is available, I can igure out how to put it behind a bomber 4BT est 145HP/450lbs ft lbs.

 

[Joe G.]

The 1-2 and 2-3 shifts are controlled by a fly weight governor. It operates a little valve that regulates the governor pressure. It should be 1 PSI per MPH. For example 20 PSI for 20 MPH. Close is ok so if it's off a couple of PSI it will still work ok. This is NOT adjustable as far as I know. The shift points can be moved by adjusting the kick down cable or the line pressure screw on the valve body. OD and lock up are controlled by the PCM with TPS voltage being one of the factors used by the PCM to decide what to do.

 

[Strick-9]

The RH is often used for swaps.



Like you said, 1-2 and 2-3 are automatically controlled inside the valvebody.



There is a 3 wire electrical harness that plugs into the valvebody.



One 12V supply wire, and two ground wires. One wire to each solenoid.



You can easily use this transmission without a computer. Just setup the 12V wire to come on with an ignition switch.



When you ground the wire going to the TC lockup solenoid the converter will lock.



Likewise, when you ground the other wire, it will shift into 4th.



I believe that's the information you are looking for.



-Chris

 

[PKemp]

Oo.



Ooooooo!!! Another 47RH person. 1st, listen to Joe G. and Strick-9, they know whats up. I'm in the middle of a 47RH mystery right now myself. I found a very good Specs manual from www.levelten.com. They got me an ATGS 47RH Spec manual for $34. 00, took awhile they were back-ordered. Has complete illustrated parts breakdowns, test port locations, etc, etc... . I couldn't find anything anywhere else out there in the universe. Not even from Dodge itself or the local dealer.

If your really thinking about tinkering talk to these guys about a better torque converter and valve body. You won't regret it.

I'm on my 3rd 47RH now and have decided to do a complete replacement with the heavy duty stuff rather than invest another nickle in a stock part of any kind. Wish I'd done this a long time ago... . $$$$$$$$ would've been a LOT cheaper... . !!!!!



-----Pat

 

[turbomatt1]

yup... I like the RH best. basicly an old 727 w/ electric lockup & overdrive. anyone remember offhand which wire is wich ?

(green, brown, orange)

 

[Dan_69GTX]

If you are working on transmissions and need special tools - look here - no prices - just the part number and description - you will have to find a supplier of the tools.

http://www.atec-trans-tool.com/



As for shifting - yes the 1-2 and 2-3 is a lot by the gov. You can buy different weights to control shift points. Now if I can only find where that place is - If I find it - I'll post it.



Ma Mopar used to make/sell a lot of different weights - especially in the 60's-70's. Last year I tried to get some of them - no luck - all are NS1 (means no longer serviced).



Here is a pic of a couple of different weights:

http://albums.photo.epson.com/j/ViewPhoto?u=1751254&a=13489738&p=51710272



What else said here is right on!



Dan

 

[Joe G.]

There are two sets of governor weights available for our 47RH transmissions. The weights used for the V10 are different. I suspect that they would raise the shift points but don't know for sure.



Replacing these weights is a major PITA. It adds to the fun if you have a 4X4. The weights are in the tail shaft so it has to come off the transmission. Then as a reward for doing that you have to deal with the infamous park rod, OD piston, and the governor tubes when you put it back together. That can be a real deal with the transmission still in the truck. Of course, you can always pull the transmission out of the truck so it's easier to work on.

 

[Dan_69GTX]

Here is another pic of one of the gov weights!





Joe - sounds like you've already had too much fun with these transmissions!



Yes, the good old 727 was much easier to replace the weights in! - as long as you didn't have to remove the 203 transfer case!



Dan

 

[Howard Durand]

Ground wire for the TCC solenoid is orange with black tracer, PCM pin #54.

The one for the OD solenoid is brown, PCM pin #55.

The 12 volt supply wire is light green with black tracer.



I find that the 1-2 and 2-3 shift points are OK for my needs but the 3-4 shift and TC lockup are the ones that are in the hands of the all knowing TPS/PCM combination and are the ones that have gotten me into trouble.

I do have pretty good control over the TC and, of course, we always have control over OD but some things happened earlier this summer and I wasn't fast enough to figure it out.

Consequently, next week, Mr. Kondolay is going to fix it.

 

[Bseg]

To install a TC lockup switch would I splice into the orange wire with a toggle switch and tie the other end of the switch to ground? This sounds too simple so that's why I'm asking.



Thanks.

 

[Bseg]

Did a little searching and found the TST diagram for connecting the switch. Only other question is why does it say except CA vehicles? Is this a smog issue or it won't work on a CA transmission?