Im at my wits end! Wife and I bought a 1500 v8 5.9l 4x4 trans is 46re from what i can tell. A little over a year ago now. Everything seemed decent but noticed loss of power uphill. Switched out plenum plate about a month ago and did the normal fluid changes. There was a bit of oil leaked into plenum but not a whole bunch I suppose. Anyways, shortly after, the truck started to late shift like it was revving up high and then kicking into gear around 2nd to 3rd gear. Levels for fluid were perfect from what i could tell. I adjusted the kick back cable a quite a few times and I thought it had fixed the issue as it was shifting fairly great. Then a few days later I went to go to the store, slowed down at a stop sign and the truck dies with no clunks or sign of transmission issue.. Truck started up without issue, pulled into a drive way and hit the reverse. Truck moved backwards into the road and then heard and felt a huge clunk and engine died. The driveway had a lil round about so I went forward instead and got it home slowly.

After a few tests, the truck will shut off with a huge clunk if I gas it hard in reverse. When driving forward it down our rd, it will shut off on de-acceleration (almost like if you were to say, leave a manual in third gear and come to a stop without pressing clutch in) after reaching around 3rd gear.
If I gas it hard going forward from a stop or moving, the truck dies similarly to reversing. Although there is no clunk going forward it does make an awful deep sound until it is fully stopped.
I lifted the back end of the truck and put it in gear and applies gas. The wheels rotated with no issues and vehicle did not die until I applied pressure to brake. As i was braking the truck sounded bogged down and died.

Old trans fluid certainly has metal in it, no huge chunks but very fine shavings.

Iv changed a few other parts, like front end stuff and ofcourse the plenum, so I "feel" this would be the last major repair on this damn thing and if I replace the trans we can finally use this thing for hauling small yard stuff. I dont plan on loading up a trailer to haul but would like to pull a small popup travel trailer or something in the far future.

The decision\help i need is.. Could this be related to something non transmission? sounds like torque converter isnt operating correctly? I am willing to purchase a trans. Iv thought about getting one from a junk yard but who is to say that trans isnt going to have the same issue, especially if it wasnt rebuild with better parts? Infact if the truck is at the junk yard with no signs of a car crash I would be certainly be hesitant as that most likely indicates engine or trans failure.

I would only have the funds to buy a new or used trans and have me and a buddy install it. I dunno, let me hear all of your thoughts and go from there.

Also only codes that popped was after we bought the truck, IIRC it was oxygen sensor on catalytic. Which reminds me, I do have a new Catalytic converter that a purchased to see if that would help the lack of power issue, but i havent installed it yet.

Thanks and let me know if I can provide more information.

Edit: Forgot to add, that I did end up changin fuel pump, Throttle position sensor IAC (TPS voltages seemed correct when diagnosing), new ignition kit that I bundled on when i purchased plenum plate.

Edit: Removed both Oxygen sensors and throttled up drive way. Truck died upon stopping. I can stop it from dying by engaging neutral before stopping.

 

I don't think that's just an electronics problem.... but, it's possible..... I might be tempted to drop the trans pan, and see if you find anything interesting in there....

 

Old trans fluid certainly has metal in it, no huge chunks but very fine shavings. At this point im tempted to just drill some holes in the Catalytic. I have a new one anyways and i know if the plenum had issues and its WAS showing oxygen sensor codes until i replaced it. Im wondering if a clogged/bad catalytic would cause my symptoms of it shutting off under pressure?

Edit: Removed both Oxygen sensors and throttled up drive way. Truck died upon stopping. I can stop it from dying by engaging neutral before stopping.

 

Sounds like the torque converter isn't unlocking

 

Prior research leads me to believe that it is the torque converter aswell. Im hesitent to just put a new torque converter in... the truck did have 200k miles when i got it for cheap (I should have known better...)
Im currently weighing my options on just doing a rebuild myself. Iv heard its easy and i wouldnt be alone in the venture as my brother in law is quite knowledgeable and was also pointing his finger at the Torque Converter.

Anyways, unless anyone else can think of another problem that can be solved with a simple sensor purchase or something cheaper, sounds like i need to do something about the trans. Thank you guys! Preciate the input.

 

Just replacing the torque converter might solve that particular issue, but, given that the carnage from inside the tc is now distributed throughout your trans, it isn't much longer for this world. It's also possible it is some other failure in the trans....... either way, I think it's time for new one, or a rebuild.

 

Yep, I completely agree with that. No point in putting a new part on a part that is old and most likely in need of replacing anyways. Although at this point I could say that about this truck. :'(

 

I had some similar issues with my 46RE. I went ahead and opted for a full heavy duty rebuild (for some of the towing I plan to do) and a re-manufactured RV torque converter from Precision of New Hampton, IA. I also got rid of the check valve in the transmission cooler line. All is well with the transmission now.