I have a 95 Ram 3500, 5.9 diesel, 4x4, with 82k original miles. About six months ago I began to notice that at times, mostly when I would hit a large bump at Highway speeds, I would hear the motor's rpm's go up for a few seconds- this has progressively gotten worse. Then, it got to a point that I would be driving at highway speeds and I wold hear the rpm's jump while the truck began to loose momentum. By the time I get it to the tranny shop when these symptoms begin, and as I give it more throttle, the motor rapidly loses momentum and the motor begins to choke out just like it had a "jake brake".

Six months later and two trips to the tranny shop (whom I respect), we are not able to figure out why this is happening.

So far they have reset the "TV" cable, replace "CPs" or some kind of electrical sensor, and rebuilt the valve body. On the second trip, being at a loss of why this is happening, the replaced a pressure valve in the tranny.

The problem endures so now they're looking into a rare phenomenon that they've heard about where the tranny wiring is receiving foreign signals and interrupts the normal function of the electrical systems........ He said, "I know it sounds crazy", but they're at a loss as to what else it could be."

Any ideas?????

 

Oh yes, NO CODES! At all!

 

You won't get codes, because the trans is all hydraulic except for the 12 volts applied to OD and LU.

Could be several things, some as simple as a LOOSE GROUND....... Start there, check and re-check ALL engine grounds, an Alternator getting noisy can send funky signals, they sell a fancy trap, but some get around it by simply wrapping the main alternator charging wire in aluminum foil ( obviously keep it away from the terminal ), then it is on to your TPS ( throttle position sensor ) or the bushings in the linkage that control it.

The 47RH trans is really simple, it is a 727 Torqueflite with overdrive and torque converter lockup, there is really nothing mysterious electrically, 12 volts is applied to both solenoids all the time, and your PCM drags in the ground to actuate them.

Lets start with what I have described, and see if that doesn't get you back up and running right.

 

Thanks for the reply, patdaly. It looks like I'm going to try and have my alternator rebuilt.

The tranny guy confirmed that my torque converter clutch is locking in and out at seemingly random times and that's the main symptom I'm experiencing.

 

Patdaly, I've recently had the alternator, which was old and sparking, rebuilt; partly in hopes that those sparks were causing the foreign signals- we did not wrap the alternator wire in foil. I and my tranny guy are at a loss.

He said they checked to see that all grounds were snugly fastened.

Tomorrow, if I get the chance, I plan to wrap my alternator wire. Do I need to ground that somewhere?

After the tranny guy drove the truck for almost 100 miles he is sure the torque converter clutch is receiving signals which are telling it to lock in and out at random times. Just to be sure, wrapping the alternator cable could stop that, but is there any other electrical gadgets that could send foreign signals?

I sure do appreciate your reply.

Blessings,

 

possibly a bad sending unit or wire from the trans temp sending unit? as we all know it wont allow lockup until fluid temp is 70F ish

 

I did not know that, but this answers other unrelated questions I've had..... Thanks for the reply, joem.

 

yeah on cold days it will stay in 3rd for a while, then shift to OD unlocked for a few then lock up. Causes issues for me as I enter a 70MPH zone within 2 minutes of startup and have had traffic blow past me in the bike lane as they are upset with my speed. Here is a clip, Loud sms message at 1:11 as the old android isn't smart enough to mute them during video.

 

That is so simple to fix. I start my truck cold and let it idle a few minutes in drive with the parking break on. I use trailer tow button in to keep it from going into OD and locking. The trans won`t shift and lock till the trans warms up. simple as that. I also don`t baby my truck and soon after it starts to move the fuel petal is on the floor. over 300000 km and no issues so far.

 

great idea! My ebrake cables are still not hooked up as the new Disk Dana 70 is quite different.

 

If they did not remove the ground connections and clean them, then reinstall them, the job is not done. Unfortunately dirt/corrosion in the ground connections, even if they are tight, will cause problems.

Chris

 

Okkkkkkkaaayyyyyyy......... great point. I'll let them know. Thanks for sharing, Stamey.

 

http://www.cumminsforum.com/forum/94...d-hunting.html

 

Ok, after about 4 months of trying to get my tranny issues resolved all the while trying to make a living using my truck, I've finally got it fixed. After a valve body job, rebuilt starter and alternator to correct some electrical issues that might have been a factor, I went in and told them (the tranny shop) about what y'all said. I told them to replace the tranny temp sensor and they did that for free cause of all the time and $$$ it took to get to that point and it is now resolved. The sensor was bad, sending intermittent signals, and it's connection was loose.

This final solution was thanks to the advice y'all gave me. I am grateful to you fellas for taking the time to chat with me.

Bless, y'all.

 

I stumbled across this thread searching for TPS issues. The video "joem" posted mimics almost exactly what my truck does. I've asked a few questions about the way my '96 shifts in the past. I use the block heater when it's cold outside, (it's on a timer for 3 hours before I go to work), and on the way TO work, it shifts fine. On the way home, (cold), it reaches a point where the trans is almost ready to lockup the TC, (around 45mph), and the engine surges between 1800 and 2100 rpm. If I give it just a little less throttle, it seems to lock. Is this normal, or is there something else going on?