I have not had time to get under there and look into it. I was away for a
while and left a lot of my stuff stored at my moms place.
Now I have it all out, I am starting to notice some tools -n- stuff missing
so I am having to go buy some new things.
I will probably go out later today or tomorrow and start on it.
I am wondering though...is the 48RE better and compatable? I wonder if I
shouldn't go to a place like autozone get a 48RE and just put in there and
maybe they won't notice me giving them a 47RE in its place? ;-)
I still have to go and buy a compressor, so I guess I can start taking it
apart them go buy the compressor for the air tests.
Or maybe I should just go rent some hydraulic pressure gauges?
According to the manual that method would get a close pinpoint without
having to disassemble it yet.
Thanks for asking.
If you're serious, it can be done. You'll have to do a little re-wiring of
your existing park/neutral switch connector, as the 48RE uses a range sensor
that indicates the position of the manual valve (PRNDL). Everything else is
compatible, and will just bolt or plug into place.
Yes. Just about every clutch pack has more friction material, most notably
the overdrive direct clutch, which has been beefed up from 8 steels/7
frictions to 23 one-sided frictions (sort of a steel and a friction in one).
The 48RE also has better fluid flow to the overdrive unit. Those were the
two biggest factors with 46RE/47RE failures. The planetaries are 6-pinion
units, compared to 5-pinion in the 47RE, resulting in a stronger gear set
(though breakage of a planetary in a 47RE is rare, unless you're racing or
sled pulling with the thing).
Nope - never sat down and put one together - I just did a cursory scan of
the wiring between the two back when we were talking about stuffing a 48RE
into your truck.
Now that I look at it again, it seems fairly straight-forward. On the 47RE,
the park/neutral switch has battery power on pin 1, park/neutral position
sense on pin 2, and the backup lamp feed on pin 3.
On the 48RE, the range sensor has battery on pin 1, park/netural sense on
pin 6, and backup lamp feed on pin 4. Pin 2 is a mux output to indicate the
position of the manual valve (drives the PRNDL display on the instrument
cluster), and pin 5 is a +5V supply for that mux output (the TRS has several
resistors in it, so I'm sure that pin 2 output simply changes the voltage
based on manual valve position). Pin 3 isn't used.
So, assuming you get the connector that plugs into the TRS with a little bit
of wiring, you'd simply hack off the park/neutral connector from the old
truck's wiring harness, and splice pin 1 to pin 1, pin 2 to pin 6, and pin 3
to pin 4.
Oh something else I did not bring up.
Before the trans failed, it did have a bit of a problem that seemed to get a
little worse over time.
That is after sitting for more than a day, I would have to allow the engine
to idle for a moment or two after starting the engine because the trans
would not engage until after a moment or two till after the engine started.
Over time it became worse after just sitting overnight and would do the same
I went ahead and put some cheap trans fluid back in it and with the new
filter to see what would happen.
It seems a tad bit better. The truck will slowly star moving now if I rev
the eng high enough. To me it seems the trans just needs more pressure to
Today it also posted some codes:
Okay what about the codes?
Seems P0753 is :Transaxle 3-4 shift solenoid/transaxle relay circuits
and P1765 is Trans. 12 volt supply relay control circuit
I recall those codes coming up before, but kept disapearing.
Fuel level sending unit no change over miles. Hmmm.... interesting, but
not trans-related. Notice any problem with your fuel gauge?
You had this one, too - Transmission +12V supply relay control circuit
So, there's some type of electrical problem. First, check and make sure the
transmission relay in the PDC is good. Next, pull the relay, and with the
engine running, check for +12V in the relay socket where terminal 86 would
plug in to. Check for ground in the socket where terminal #85 would plug in
Shut the engine off, and with the relay removed, first check for +12V in the
socket where terminal 30 would plug in to. If no voltage here, check the
large 20A fuse in the power distribution center.
If voltage is good, insert a jumper into the socket between terminals 30 and
87. This will let you test the transmission connector without the engine
running (never good to crawl under a running vehicle). With the jumper in
place, you should be able to read +12V on pin #1 of the 8-pin round
connector on the driver's side of the transmission. It should be a red
wire. If that's good, plug the connector back in, and using a lead from a
test probe (with a sharp, skinny pin on it), ground the brown wire (pin #6).
Listen for the OD solenoid going 'clunk'.
Hopefully somewhere in that list of tests, you discover a problem.
Crap - I just remembered that you already pulled the transmission. In that
case, you can still do everything above, except the last part. With the
trans on the bench, you can just apply +12V to pin #1 of the connector, and
ground to pin #6, to test the OD solenoid. You can even do this with a
fresh 9V battery, if you don't have +12V DC power handy.
My panel is not marked at all and I do not see which are terminals 30 and
Unless you mean the very place where the jumper is already in place. I guess
that would mean I shoudl be able to go ahead and test the voltage
at pins 1 & 8 of the connector?
going to do it now
It seems the problem was at pin 7 on the round connector.
Some reason the wire was previously broken or cut then put back together
with crimp connectors.
One of the crimps did not hold well and came off. I temporarily put a
alligator clipped jumper wire.
Well this puts a dampner on my hoping it was only an electrical problem.
The truck afterwards seemed to want to drive. I kept driving it back and
forth for a few times to see if it would want to drive.
In the end it does not want move again.
Doesn't Dodge have a recall on those junker RE47s? ;-)
Pin #7 is the torque converter clutch solenoid control. Are you sure it was
pin #7? Was it an orange wire with a black stripe?
It sounds like you have a very hacked-up truck... spliced transmission
wire, jumpered/bypassed relay... geez, what else could you find if you
looked closely? (*)
Oh, I didn't mean to give the impression that the above would address your
apparent lack of fluid pressure to apply your clutches - no, you still need
to air-test the VB, and most likely disassemble and repair what's failed.
* This is a diesel, right? The previous owner may have installed a "mystery
switch", allowing direct control over the torque converter lockup. Do a web
search on "diesel mystery switch", and read up on it. I don't think
bypassing the transmission relay was part of it, though - so that part's
still a mystery (sorry for the pun)
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