47re Torque Converter Lock - Electrical Issue?

[nwilliams]

Hey guys, this is my first post but I have read a lot on this forum and have found help several times here. My issue now seems to be something in the electrical system causing some weird torque converter symptoms. First off, I have a 1998.5 Dodge 2500 4x4 24 valve with 177,000 miles and a 47re that has been built with a BD Stage 3 kit along with a single disk billet converter that has roughly 22,000 miles on it. It has ran flawlessly up until about a week ago. My issue is very consistent. I can take off with normal throttle from a stop and the transmission will shift perfectly 1st through 4th gear and the torque converter will lock perfectly at around the 45 MPH mark (not sure of exact speed due to 35" tires and speedo not being calibrated), and from there I can accelerate to highway speeds anywhere from 50 - 65 miles an hour with no issue. My issue occurs the second that I let off the throttle and let it idle as if I were coming to a stop and braking. The torque converter will unlock as normal, but for instance if I am going 60 mph and let the throttle go idle for even a split second and then give it more throttle to continue driving, the torque converter never even thinks about locking back up, it will simply rev high in 4th gear and drive. If I do come to a stop (or slow enough to downshift into 3rd), I can resume and shift back into 4th and the torque converter will once again lock until I get off the throttle. Basically, the converter will not lock more than one instance per 4th gear shift. It has never done this before, as normal operation would be that the torque converter locks back up after resuming throttle. My truck has two brand new batteries less than a month old with new and cleaned terminals and I have verified that all plugs on the transmission are clean and firmly pressed into each socket and all grounds are properly connected. Any assistance or advice would be greatly appreciated.

[Me78569]

that's an interesting one.  

[nwilliams]

I'm not going to eliminate the thought of a faulty converter, but when it locks, it locks very solid. Really doesn't seem like a mechanical issue.

[Frankstein]

try reset APPS and inspect the plug,connection on the altenator

[nwilliams]

I have reset the APPS the other day and that did not help. My alternator has some burnt looking internals after further inspection. I am putting a NEW Bosch alternator on it today and will post the results.

[WiscoRedkneck]

4 hours ago, nwilliams said:

I have reset the APPS the other day and that did not help. My alternator has some burnt looking internals after further inspection. I am putting a NEW Bosch alternator on it today and will post the results.

I know rf interference can cause issues with the apps sensor and the TC hopefully the alternator fixes it.  After my transmission got rebuilt randomly one day I had horrible issues took it in, the shop added a ground on the apps sensor and reflashed the pcm.  Then it happened again and they installed a rf kit on the truck.  apparently it also has something to do with the premature failure of the 47re referring to the excessive locking and unlocking of the TC...

Edited January 14, 2017 by WiscoRedkneck

[Mopar1973Man]

Ditch the noise filter and fix the alternator.

[WiscoRedkneck]

2 hours ago, Mopar1973Man said:

Ditch the noise filter and fix the alternator.

I don't believe it's the alternator for me at least...  it was new when the truck got put back on the road.  I do have light controllers for emergency lighting, pure sine wave inverter and technically 4 radios counting truck stereo.  Get my dual band in April so I can remove one.

[Mopar1973Man]

Ahhh... The radio might be the cause of the noise. So yeah you going to need the filters but something system wide and not just the PCM. You might consider a heavy duty alternator like Nations Alternators or Mean Green Alternators.

[WiscoRedkneck]

39 minutes ago, Mopar1973Man said:

Ahhh... The radio might be the cause of the noise. So yeah you going to need the filters but something system wide and not just the PCM. 

The transmission shop installed the filter so I would have to find out what it is and what it's all protecting, never thought much about it since it seams to be working... 

[Me78569]

The filter is covering up an issue.  Junk the filter and test for AC noise.  

 

 

It's like putting duct tape over a hole in a canoe...  it might work for a bit, but at some point it will let loose and the result of the issue is a lot worse in the middle of the lake compared to on shore.  

[WiscoRedkneck]

1 hour ago, Me78569 said:

The filter is covering up an issue.  Junk the filter and test for AC noise.  

 

 

It's like putting duct tape over a hole in a canoe...  it might work for a bit, but at some point it will let loose and the result of the issue is a lot worse in the middle of the lake compared to on shore.  

How do I test the high bandwidth emergency radios?  I totally agree with you on the canoe analogy.  

[Mopar1973Man]

I would test for the AC noise off the alternator first with all the radios and accessories OFF. 

 

Then test the AC noise again while transmitting on the radios and see if the Rx signal is seen on the AC noise test.

 

PCM noise filter is a band-aid because it only going to protect for that one circuit. If your going to install a noise filter because of the radio you going to need a big one that will filter for the entire truck. This will pose a problem you will have to make a schedule to unhook the filter and test the alternator for noise levels because the noise filter will mask the problem till it does damage ot ECM, PCM and/or VP44. 

[Frankstein]

do you check and smell your tranny oil? if there's some parts in it???

[nwilliams]

The new Bosch alternator did fix my issue 100%. I don't smell any fluid or anything like that, but I would hope not as I installed a Derale 15900 trans cooler under the bed just a few weeks ago and verified that I had no leaks. Thanks for all of the advice! I had just never heard of this specific of a consistent issue with the alternator problems, so if anyone else is fighting this just put a new alternator on!