Hello I bought this truck about two years ago. I am the third owner. Second owner only had it for a few months and didn't understand what he had really as all upgrades were done before he got it. It was immaculate and had some tasteful mods. Here are the truck details.

2007 mega, 4x4, 5.9, auto. Lariat

Mods (that I know of) banks inter cooler, high ram, banks intake. Full magnaflow exhaust, 50 hp nozzles, I think ddp turbo upgrade, edge evolution cts set on tow, full gauges, boost fooler and mag hi tech trans pan.

Since I purchased it with 90k on it I added cat/cummins fuel filter kit with a low pressure light.

Truck has been awesome for the almost two years I have had it. Except for one cracked injector line and brakes it has been perfect.

Few days ago I got it really stuck in some mud. Backed over a ditch that I filled over the summer that hadn't compacted. It was pouring and I sunk the whole left side to the frame. I worked the truck pretty hard trying to get out before towing it out with an excavator. Not sure if I overheated the trans because it was pouring and dark and I was pissed.

Next day I was up in the woods and noticed that at low speed it felt like the trans was surging or slipping. 10-25mph range. Didn't do it at higher speeds. Pulled the dipstick and it smelt a little burnt. I am a hobbieist mechanic and know what that usually means. Got home and hit the forums to see that these 48re's are known to do that and the governor solenoid is often the culprit. What scares me is the fluid smelt burnt.

What I'm thinking is drain and flush the fluid, change to the GM upgrade solinoid and new transducer and pray it works. Am I on the right track? Everything the original owner did seemed to be top notch. He did put the deep pan on but I don't know if he upgraded the trans at all. Is there anything I should look for? Is there anything else I should upgrade while In there? Might try to adjust the bands.

I have a lift in my shop and have built hot rods, rear ends, complete race motors but never messed with the insides of autos much.

Thank you in advance for any help.

 

Well I would all that you say.
Make when you got the pan off, definitely adjust the two bands to spec. One adjuster is in the oil pan under the filter and other outside on the drive side up above the oil pan. There's video and forums about it.
Since your in there, what others do to is upgrade the valve body for more flow, may consider that.

But if you want to go to the extreme, then upgrade the torque converter and get the upgraded kit for the tranny internal parts (heavier clutch packs and shafts)

 

Assuming it was a stock 48RE with your mods, it's time for a trans built to take the power.