I have a 2012 F250 6.2 with a service body on it. The previous owner replaced the transmission with a moco reman roughly 50k miles ago and kept up with the service up to the point I bought the truck.

I've put roughly 5k trouble free miles on it since I bought it. Recently when trying to pass a truck on the highway, when accelerating and dropping down into 5th from 6th, the trans slammed into 5th. I've experienced the harsh up and down shifts on these units before, but nothing like this.

Fast forward, I hooked up my snapon Zeus thinking i'd see a transmission code ( cel was already illuminated due to a fuel level sensor issue), but there were none. I remember back with the 5R and it's shift flares/solenoid issues, and decided to check the fluid. Level was fine and fluid looked/smelled normal. I did drain and refill just for peace of mind with LV. Recreating the issue is pretty easy below 50-55mph, but not so much at higher speeds. It will intermittently happen in all scenarios(i.e tow/haul on or off, manual downshifting or by throttle). I cleared the adaptive learning and properly did the drive cycle and wasn't able to recreate the issue for a couple of days, but then it came back.

I did do some research prior to this post, but it seemed like the majority of issues were 1-2 and/or 3-4 up or down. Could this be just another solenoid/valve body issue?

Any other input?

Thanks in Advance!

 

Update, I've noticed the issue now affecting other shifts intermittently. 1-2 sometimes 2-3 and occasionally 3-4. Any thoughts?

Thanks!

 

Pull the codes with forscan or something of the like, chances are the transmission is throwing codes that will help you figure it out better

 

Still no trans codes. There never have been any since this issue started.

Thanks!

 

There should be a warranty on the rebuilt tranny…maybe even an extended service plan…investigate that

 

You are doing everything I'd do. Have you dripped the pan to examine for mud & chunks? Did the magnet have anything on it?

Try disconnecting the batteries for 30 mins. Hook back up and take it for a kill run.

If you are from the rust belt check all weather tight connectors to the trans. Corrosion will wreak havoc on electronics.Bad or missing grounds will do the same thing. Find the grounds verify they're clean & tight.

I agree with investigating the warranty on the reman.

Next level is to take it to a shop good with HD trucks or find a good Ford dealer that does trucks. It needs to be hooked up to a Ford scanner. The pressures should be checked too.