Transmission repair or no?

[irfan5911]

2018 2500 diesel. in addition to solving the problem I am trying not get screwed by the mechanic$: Transmission is having issues and now mechanic is saying it’s torque converter and the we need a swap. He said he reset the computer and now it’s driving but it’s slipping and shifting at high RPM around 5 to 6k.

 

[Dennis Shellito]

How in the jolly blue world is this "mechanic" getting an ISB revved to 5-6,000 RPMs? I don't know what to even comment on that. I am a firm believer in re-manufactured transmissions over repair/rebuild in anything built in the last 40 years. I would also get your truck out of the hands of this person ( I would never refer to him as mechanic again ).

 

[irfan5911]

So I’m guessing you cannot conclude pressure plate when you check fault codes?

 

[irfan5911]

So I finally got out to the truck so I can see for my self. It’s driving fine in my opinion. So the question is can a reset resolve a transmission problem like this? I am not getting check engine lights either.

 

[nlambert182]

Doubtful. I assume this is a 68RFE.

1) As another poster said, you can't rev an ISB to 5-6k RPMs. 6k isn't even on the tach.
2) The 68RFE "slips" a bit between shifts from the factory. It's called fluid coupling and is designed to do that so as not to shock the transmission with 850 lb/ft of torque at one time. Is that what he is referring to? Sometimes it will feel like it's slipping right before the torque converter locks up in 4th gear, but again... fluid coupling.

I think we may need more details.

 

[irfan5911]

P0871
P0735
P0729

After driving for a several minutes the check engine light comes on and these are codes

 

[nlambert182]

P0871 is a pressure code for the valve body. This is most commonly seen in trucks that have been tuned with the line pressure turned up (usually 250psi or higher), but it has happened on rare occasion on stock trucks that have been worked pretty hard and used to tow at the limits of the truck. If the trans has been running hotter than normal, it could in turn damage the valve body.

P0735 is Gear 5 incorrect ratio code. Again, typically seen on tuned/deleted trucks that have been turned up. If not, the other options are a bad shift solenoid or a faulty harness or connector.

P0729 is Gear 6 incorrect ratio code. See above.


OP - questions for you:
Is (or has it been) this truck tuned/deleted? Even if you add a 75 hp tune, that is roughly 150 lb/ft torque increase. A 68RFE won't like it.

Are you running much larger than stock size tires? Maybe 35"s or 37" tires?

What is the transmission operating temp? You should rarely ever see it crest 190 degrees even if it's scorching hot outside and towing a heavy load. Usually you'll see somewhere in the 165-175 degree temp range.

Is the fluid at the proper level, and what color is it? When was it changed last?

A bad valve body "could" cause these other codes if it has not been tuned, so it doesn't necessarily means the trans is toast. But you definitely need to get it corrected time now.