I cannot drive at all for the transmission feels like something is wrong

Hmm I am scratching my head on this one at the moment.

The P0299 Code indicates an "under-boost" condition on one of the turbo's. And the P054C indicates a problem with the Variable Valve Timing on one of the cams, (Bank 2) it says that it is too advanced.

I am trying to see how these codes could be related to each other or if it is just a coincidence. As far as the noise goes, since the turbos are mounted low and to the rear of the engine, perhaps you are mistaking it for the transmission? Is it possible to get a recording of the noise?

Jon

Yikes! Hard to really tell exactly where the noise is from the video but wow! I wish I could get under my Explorer that easy! So when you are under there, where exactly does that loud banging sound come from? The front, middle, or rear of the transmission? Are the U-joints okay as well? Also, can you give me some history of perhaps what happened before this? Were you out mudding or anything?

Jon

Okay, it is hard to say for sure but I swear from the audio that the noise is coming from the rear of the vehicle. Can you take the driveshaft off and check both U-joints, and while that is out I would turn the pinion shaft on the differential and see if you feel any clunking from inside the differential housing.

Could be that water intruded into the U-joints and caused some damage there or perhaps you had water work its way into the differential housing and damaged the bearings or gears.

I do not blame you for not not driving it! One thing is for sure, the codes you gave earlier are definitely not related to this clunking noise!

Jon

So the U-joints were okay and not binding up?
Could you feel the clunking when you turned the pinion shaft?

As to the codes, the low boost code is turbo related, and the other code is for the Variable Valve timing.

The low boost could mean a seized turbo bearing (thinking about the water you mentioned). Or it could be a result of the second code you mentioned (but that would be a stretch of the imagination).

The VVT code is puzzling. There is a regulator that controls the cam timing hydraulically using the engine oil pressure. It could be that the regulator is stuck open causing the came to run fully advanced. This will cause cylinder pressures to drop but I am not sure if it would be enough to cause low flow to the hot side of the turbo. I suppose it is possible. I would check the pressure regulator(s) for water damage and corrosion in the wiring. I am not familiar with that specific engine so I will have to dig a little to find exactly where that regulator is.

Jon

It sounds like the differential is having an issue and the noise is telescoping up the drive shaft. Please remove the driveshaft and turn the pinion or remove the rear differential cover and inspect. These guides can help.

https://www.2carpros.com/articles/how-to-remove-a-drive-shaft

and

https://www.2carpros.com/articles/differential-service

Please run down these guides and report back.

Cheers, Ken

Oh wow! Sorry to hear that. That is is why I kept asking about the u-joints. Since the driveshaft separated from the truck, I would recommend you take it in to be inspected and either repaired or replaced. Glad you are okay though! Still since the vehicle has been through such deep water, you should check and change all the fluids including the differential and transmission.

Jon

That is a good plan. I would rather see you get a new shaft anyway. Trucks with lift kits like yours put a little extra pressure on the U-Joints so its good to keep an eye on them anyway but when you mentioned the deep water I figured it was worth a look at them. Just make sure you check those fluids. Let me know when you want to talk about the trouble codes you mentioned in your original question!

Yep, they do not plan for that kind of failure so there will be no codes.

Oh definitely! Seeing as this vehicle was under water as you said. Most likely water got into the differential housing. I would remove the cover and axle shafts then inspect the whole rear axle assembly from wheel to wheel. Replace all bearings and seals etc. For that matter though it might be cheaper to buy a used unit. Make sure the gear ratio is the same if you do.

Which direction are you up for?
Jon

Nice! Yep that is what it sounded like. Nice work doing the job yourself. Can I ask how much the gears cost?