Hello I’ve read many posts on here and solved many problems on various trucks from articles I’ve read here so I believe y’all can hopefully help me here. I have an 03 ram 3500 5.9 with a 48re. I bought this truck with a bad transmission so I had it rebuilt. I installed it and now I’m having shifting issues. If I start the truck and the first time I put it in drive it starts in first and drives fine but after that it won’t downshift below 3rd. It will easily downshift manually into 2nd but will only manually shift into 1st if I shift it prior to stopping and then it will shift in just before the truck stops. The truck is completely stock I have a smarty touch but only use for monitoring the engine. I’m at my wits end I need help to figure this out. Thanks 

 

I guess I should also say that when I stop in drive it starts in 3rd unless I manually downshift 

  Check the transmission relay that it's sending power to the trans.   If that's OK then the governor pressure solenoid or transducer may not be working.

Well I switched the relays that didn’t work I even removed the fuse box cause I’ve heard of corrosion issues and cleaned it up the terminals that look like where the relay would be looked a little dirty so I cleaned and put a little dielectric grease on them. Still the same issue. As for the governor pressure solenoid that’s a new borg Warner done when the transmission was rebuilt. If I get the truck to speed into overdrive it will lock up fine and if I mash the gas it will downshift but not below third. 

Sounds like you need to pull the codes and see what is stored in causing the 3rd gear start. There are a few items.

 

Renew your membership and download the book. It's available for download.

 

This is on page 36 of the ATSG book, but you should start back at page 34.

 

 

Pull codes, pressure checks, compare the psi to what the data back to the PCM.

 

After the easy stuff like checking the fuses and power to the PCM, the connector it self.

 

Good luck with you repair.

 

 

 

Well I pulled the pan replaced the solenoids and transducer which were already new still same problems. I need help both my trucks are down now and I need this one to work if anyone can help I’d really appreciate it. Thanks 

I cannot communicate with the transmission with my scanner it’s a cheap scanner not sure if it’s the scanner or something else. My smarty tuner will show me codes when I unplug the transmission harness so it seems to be communicating with the transmission 

I have replaced the tcm and swapped them back and forth with no change in the issues 

48re has a TV motor I think.

To me it sounds like pressure under idle conditions is low. 

I'd be looking at TV issues. 

 

I dont know what how or if TV on 48re is adjustable 

 

That’s what my transmission guy and I think too. But we’re both stumped on why!

If it were mine I'd unhook TV motor and zip tie or wire TV valve to what looks like 70% of its travel then go for a drive it may or may not drive correctly and may cause harsh firm shifts under light throttle.  It should downshift under brake pedal. 

 

If it does then I'd be looking into TV motor or wiring, sensors that feed it and tell it what to do.

 

Also you may with key on truck not running see the motor turn the valve as throttle goes from idle position to wide open position. 

 

I'm guessing at that though I have no idea if motor will move without the truck running. 

 

You may also test at idle maybe rev to half throttle seeing if it moves or not.

 

Again all just guessing on my part.

 

A well placed go pro camera could also watch it as trucks driven through the gears.

Edited December 10, 20195 yr by Evan

I don’t have a tv motor that’s on a 05 up truck. My transmission guy is telling me it’s probably electrical. But where do I start. Is there anyone on here that has an idea I know there are some super smart people on this sight from the articles I’ve read. Is there anybody out there that has any ideas!!!

So where the he’ll do I find the atsg on here. I was told it’s on here but can’t find it anywhere 

Edited December 13, 20195 yr by Fumminsman

Might talk to @Dynamic

4 hours ago, Fumminsman said:

 

So where the he’ll do I find the atsg on here. I was told it’s on here but can’t find it anywhere 

Go to the downloads section and it listed under Dodge Factory Serice manuals. Scroll down and you should see it.

No TV motor opens you up for more help. 

Makes troubleshooting easier.

 

Is TV valve moving when throttle is pressed? That would be my first thing I'd look at.

 

All battery connections clean and secure even grind heater block below drivers battery all ground and cables on starter along with obvious connections at battery posts.

If I was they're I'd go to grid heater connections below battery these are often over looked and can cause issues when the nuts come loose.

 

Does it have a resistor to fool computer from ever seeing 105psi. Tranny builder would have put resistor in at same time as shift kit if they put a shift kit in it.

 

How many miles on rebuild is they're more than normal clutch material in the pan. Big chunks are bad 

 

Is filter plugged? Should have serviced tranny a couple thousand miles after it was built.

Any bolts screws laying in pan. Anything come unplugged inside tranny.

 

Have bands been correctly set now or during tranny assembly?

 

Some if this stuff youd assume is correctly set but I've seen some crazy **** that I myself have over looked and that those that are payed to do also over look or just dont know.

 

Its probably something simple. Good luck

 

Correct amount of ATF in transmission? 

Edited December 13, 20195 yr by Evan

 

Well it ended being the transducer in the transmission even though it was already new

i was thinking also TV cable had that problem on my 01 did the same crap found a frayed cable was keeping the valve from returning all the way.

Glad you figured it out. Sometimes the simple things hide behind new things.