Engine/Transmission (1994 - 1998) 47RH torque converter unlocking

[ikoch]

I'm having a problem where while driving down the freeway in lockup, the torque converer will unlock for a few seconds and then lock back up. My speed does not change, all that happens is the rpms will increase for a few seconds and then go back down. One time it came unlocked, and would not lock back up, after about ten miles I had to slow down, when it shifted back up through the gears it went back into lockup. It happens whether I am towing or not. Every once in a while I will go through a long period without seeing the problem. I am wondering if anyone has had this problem before. Do I have a bad conection or solenoid somewhere or is the torque converter going bad. My truck is a 1995 dually with an automatic and 3. 54 gears. Any input is greatly appreciated.

 

[Joe G.]

This sounds like a Throttle Position Sensor (TPS) problem. It can get dirty and do this. It's the black box on the end of the throttle linkage mess near the front of the injection pump. One thing to try is to dose it good with contact cleaner and work the throttle linkage back and forth a few times. There is no easy way to open it to clean it, but usually enuff cleaner gets in around the shaft to work. If that fixes it then apply the cleaner everytime you change oil and you should be ok. If it does NOT fix it then it is too dirty for that to work. Try pulling the three connector wires out of the cable so they are not next to any other wires. That should do it even for a dirty TPS.

 

[jpate]

Hear is the answer... from someone that HAD the same problem. Yeah I thought it was the Throttle Position Sensor... I even parted with $193 for a new one, and it didn't do a thing! When I got back home, I went to my (un) friendly Dodge repair shop. The problem was solved with a temperature sensor. This sensor doesn't allow the transmission to shift into overdrive if the temperature is too hot or too cold. In my case the sensor didn't know how to measure at all (shot). This sensor is attached to the line that comes from the transmission to the cooler. Don't panic -- this sensor doesn't cost much. -Jim-

 

[Dave Remillard]

One More Suggestion

If it is the TPS, and you have done all that Joe suggests and still have problems, try this. Its important to get the proper voltage from the TPS. In my case, even with a new sensor, I wasn't able to even get 1 volt. I'm not certain what the recommended voltage is, but I believe it's around 1. 1 to 1. 2 volts. I first removed the TPS, then used a 7 mm socket to loosen the three bolts that hold the bracket that the TPS bolts to. I was able to rotate it counter clockwise quite a bit ( a 1/4 "). I then re-tightened those three bolts and installed the TPS. I am now able to adjust the TPS very easily. Presently mine is set at 1. 15 volts and works much better. I plan to readjust tonight to get 1. 2 volts and see if that is even better. You will notice a change in shift points also the higher the voltage is set. Hope this helps, and by the way what Joe said about removing the three wires from the loom they presently reside in is a good idea also. A thing called electrical noise, or as I call it induced voltage, is a real problem. Lots of additional info from the search feature if you have lots of time to read. Good Luck



Dave

 

[ikoch]

Thanks everyone, I'll give all these suggestions a try, and I'm sure one of them will be the answer.

 

[illflem]

An easier solution to low voltage from the TPS - rather than move the mount remove the metal inserts where the hold down screws go through the tps and use a round file to elongate the holes. It doesn't take much. The electronic cleaner has worked well for me, aim it at the tps shaft while moving the throttle back and forth.

 

[Dave Remillard]

Bill is correct about elongating the holes. However on mine I had done that but still could not get the desired voltage. IMHO moving the bracket may be a better way. The reason being you can leave the metal sleeves in place. The sleeve serves as a support so to much tightening of the hold down bolts don't breaker the TPS housing. The important thing is to do what is needed to get the voltage adjusted properly.

 

[DuallyDean]

One other note about the trans temp sender (located on the driver's side of the trans in one of the cooler lines)--

My rig is no spring chicken and leaks a little transmission fluid (and engine oil), which gets into the (supposedly) weatherproof connector on the sender. After enough gets in, the transmission behaves exactly like described. I usually have to unplug the sender and spray it clean with contact cleaner, after which it works fine for another 10,000 miles or so.

 

[shendren]

i had the same symptoms as yourself... ... ... i replaced all of those parts... ... ... ... tps, temp sensor, gov press solenoid, cleaned the **** out of the tps, adjusted the tps many times, reflashed the pcm, new pcm, capacitor filters in the system, etc... . no fix..... then pulled the tps wires out of the harness and put them in their own loom and that stopped the problem cold! several on this board have done the same. the fix was suggested by bill kondolay. it is probably electrical noise in the wiring harness.

 

[KOwens]

Originally posted by shendren

i had the same symptoms as yourself... ... ... i replaced all of those parts... ... ... ... tps, temp sensor, gov press solenoid, cleaned the **** out of the tps, adjusted the tps many times, reflashed the pcm, new pcm, capacitor filters in the system, etc... . no fix..... then pulled the tps wires out of the harness and put them in their own loom and that stopped the problem cold! several on this board have done the same. the fix was suggested by bill kondolay. it is probably electrical noise in the wiring harness.

shendren... KOwens here!



I have the same problem with my TCC lockup. This has been a problem from the get go in 1995... and now I loose my cruise control at the same time the TCC fails. I realize both the TCC and cruise control rely on most if not all of the same sensors... but do you recommend I do the harness fix first to fix this problem? Since I have also replaced the TPS and transmission temp sensors many times over the past eight years, I was beginning to believe I had a "bird brain" problem with the PCM... a $550 part in my area (San Diego). I was interested to see you had also come to this costly conclusion with no success. Please let me know what you think about my TCC/cruise control woes. Thank you.

 

[KOwens]

I am trying to reply to shendren... and just learning how to navigate this site... new TDR subsciber... and put this in as a quote the first time around... my bad! Anyway, I could use some advice:



shendren... KOwens here!



I have the same problem with my TCC lockup. This has been a problem from the get go in 1995... and now I loose my cruise control at the same time the TCC fails. I realize both the TCC and cruise control rely on most if not all of the same sensors... but do you recommend I do the harness fix first to fix this problem? Since I have also replaced the TPS and transmission temp sensors many times over the past eight years, I was beginning to believe I had a "bird brain" problem with the PCM... a $550 part in my area (San Diego). I was interested to see you had also come to this costly conclusion with no success. Please let me know what you think about my TCC/cruise control woes. Thank you.



P. S. what does "reflashed" the PCM mean???

 

[shendren]

cruise also drops out? i would check the brake switch. adjust it then drive, then get a new one. if that's the case... ...



there are about 5 inputs to the pcm that kicks the trans out. vss, trans temp. , tps, brake switch, and one more i can't think of... ... ...

 

[KOwens]

Thanks shendren,



I'll check out the brake switch situation first. Then return to the TCC problem. Probably get to it this weekend... I'm kinda swamped at work this week. Anyway, thanks for the help... it beats working in a vacuum!

 

[DKayser]

lock/unlock

My 95 did this when I bought it. Put the mystery switch in to cure it. After servicing the trans, I drove it on the freeway & forgot to lock the switch. No problems then, or since. Check fluid color, if it is showing any shade but red, dump it! Chryslers need fluid & filter changes @20k.

 

[KOwens]

Thanks for the input DKayser.



Are you talking about a switch to manually lock up the TCC? If so, that is what I am doing currently... until I can get this problem resolved. I'm not thrilled about having to deal with this... especially since traffic pretty well sucks in San Diego... and you never know when you will need to panic stop to keep from hitting some hostile SUV on the freeway. I've forgotten to switch it off before... and the motor gets grumpy sounding as you begin to slow down in forth gear... luckily I haven't stalled it... yet! Mileage sucks without the TCC engaged on the freeway... so I'll stick with the manual switch for the time being. I'll keep an eye on the fluid, however, but I do my own service on the transmission... filter... and front/rear band adjustments... so I keep pretty close tabs on the fluid condition. Anyway, thanks for the input.



Kevin

 

[PKemp]

What is this mystery switch? And... ... . how do you adjust the bands?



-pat

 

[KOwens]

Hi Pat,



The switch I'm talking about places a ground on the PCM side of the TCC solenoid. I'm having trouble with my automatic lockup so I use the switch when it is not working properly. Once locked up, however, if you forget, it can stall the motor since the automatic transmission can no longer downshift from high gear. I honestly don't know what the "mystery" switch is... that's why I asked.



The front band (1-2 upshift/downshift) can be adjusted from outside the 47RH transmission. Located near and above the shift rooster/throttle. The rear band (reverse gear) is internal, and must be adjusted with the pan off the transmission. Both require a torgue wrench to do the job right. Good instructions in the Dodge repair manual.



My defective 47RH lost the 2nd gear kickdown band lever... snapped in two at the reaction pin... and I had to pull the transmission to replace this part. Major pain in the rear to get the 4X4 transmission/transfer case out/in as a unit... just to pull a pipe plug, remove the pin, and swap out the $20 part. If your front band gets too far out of adjustment, you may get to do this too! There is a strut that will fall into the pan if this happens. Best to keep the bands adjusted!



Hope this helps.



Kevin