What transmission do you reccomend?

My 2018 expedition is having no issues at 102,000 miles but I like being prepared.

I have a good local rebuilder but wanted to see if that was my best option. I assume there are certain upgrades that are needed but don't know what is needed.

Any information/suggestions are appreciated.

CDF Drum, the new version is designed to prevent bearing walk, and the reaction shell, which is now hard anodized so it doesn't wear away at the contact points. I would imagine everyone is using/supplying the newer style of both now. Everything else is just replace the bad/wear parts for most folks anyway.

I've had a box built for snow plowing a number of years ago that was fantastic. Mass Diesel, He will build what you want. There is also a guy in Utah that supposedly builds a bullet proof box. His market is diesel powered trucks so I would think he has to have his act together.

Sorry, I should have given a link. https://massdiesel.com/ I haven't used this guy for many years but my kids tell me he's still doing it. Looking at his current site he's expanded a bunch.

What are you using the transmission for? Towing, OTR, or just everyday use. If every day use stay with a local transmission shop. The performance shops use expensive parts and they are real proud of them. Actually they should be as they really hold together. Kinda like you get what you pay for.

I could possibly tow 3k a few times a year. If I have my local guy rebuild it will good parts it's not the same? I want it to last as I really like the truck. What is a good aftermarket rebuild that will last?

How long do cars last where you live with all the salt on the roads. That would determine what I did with a 100,000 mile car. I have a 1984 GMC crewcab that is a daily driver.

We had an 18 and a 19 with the early 10 speed transmission. Both never had a problem. We drove hard, but no trailers. Just do your regular 60k oil and filter change in the tranny and keep going. Not worth spending extra $, specially not if you aren’t driving trailer. Anyway… if you got a 108k on it without trouble, give it a tranny oil change if it hasn’t been done (usually every 60 to 75k in Fords severe schedule) and call it a day. I follow all my maintenance that severe schedule hand haven’t had any problems besides a leaking rear ELSD output shaft seal after a warranty repair issue. Even the older trucks. Everything wear and tear needed replacing, but not enginge and driveline related.
My dealer recommended this schedule for like forever now (20 years?) and it works for me pretty darn good, as I never had turbo, engine or any other problem.