I've got a 2001 F150 4x4 that I use as a daily driver to keep the miles off of my newer truck. It's been a great truck, but has 241,000 miles on it and the transmission is going out.

Pluses:
Very clean (interior spotless)
Everything works (electric mirrors, door locks, windows, etc) except the tranny
Engine still feels strong
4x4 works well
brand new Nitto tires
I paid $4k for it few years ago. Elderly lady's insurance paid me $5k for it couple of months ago (see below) and I bought it back for $500. So, I have basically no money in this truck.
Allows me to keep miles off of my newer truck.

Minus:
Tranny (duh)
Driver's side has dents from front fender to the bed from getting side-swiped by elderly lady, but I didn't care.

So the dilemma is, do I spend $2,300 to fix the tranny on a truck with 241k on the odometer? I couldn't replace it for that much money. But, it's also at the tail end of the lifespan of the motor (probably). My luck, I'd drop the money into the tranny and few months later the motor would go. Or, it could last another 30-50k miles which would be several years at the rate I'm driving it.

Talk about playing roulette. Ugh.

Is replacing the transmission outside of your abilities? I've done a few and it's pretty straightforward to swap one out in a day with the right tools and a friend. I'd bet you can get a used transmission for less than $500.

I'd get a used trans from a junk yard along with a new toque converter and jam it in. It isn't rocket surgery. You can rent a transmission jack from most auto parts stores.
Do the whole job for about $600

That's an option I'm looking at too. A friend has a transmission jack. In my younger days, I've swapped out a couple of T-400's in old chevy's and rebuilt the tranny in a CJ5. But, older age and shoulders aren't agreeing with me as much, so trying to decide if this is something I can tackle on my own now.

A junkyard tranny might not be any better than the one you are pulling out.
Unless they guarantee it and I doubt that, you might want to look for a donor vehicle.
I just put new tires on mine with 153,000.
Keeping my fingers crossed .

Junk the truck and use your new one.

I'd encourage you to go the used transmission route. In my part of the world a used trans would have AT LEAST a 30 day warranty. A useful website for used parts: car-part.com. The listings will usually tell you if there is a warranty on the part.

We recently bought an almost new Toyota Highlander to replace our minivan. The van still runs fine with 200k so we're using it until it craps out. I won't take it on trips but for all of our many runs to town, it saves a lot of miles on the Highlander and my pickup. I had to replace the tranny at about 120k. The engine is all original. It still uses almost no oil and gets about 24 on the highway. Who knows how long it'll last. Sooner or later, we'll have to make the same decision, fix or scrap.

Have it fixed/replaced as new. That's really cheap transportation.

Just keep driving it in non-essential situations. It might go for a few more years. When the tranny is truly shot, then you can decide what to do. "Preventative" maintenance on a dying vehicle is not worth it. But running it until the day it finally and truly dies is worth every penny.

Have you taken it to a transmission shop? It may, not be as bad as you think.

If you can do it yourself and want to then I'd fix it.

Paying someone else to repair a beater is a losing game. You're better off getting a new vehicle.

do it, if you have kids' use it as a teaching exercise. My dad made me rebuild old junk on the cheap, and I'm doing the same with my kids.
If my 7 year old was strong enough, I'd trust him to do breaks on a truck at this point. I was 13 when my dad made me learn how to rebuild an
engine, an AMC 258, best education I ever got. He was there for questions but made me do it. Now with the cost of a SBC, an engine swap
became an after work chore. I'm not a chevy fan but it cheap and reliable when you know what you got.

I have a friend who is a mechanic. He says even new vehicles need repairs so why buy a new one.

A hammer will last forever if you replace the handle and the head once in awhile.

The rate of repair between a new vehicle and 20 year old one is dramatically different.

Another thing to consider is insurance is often cheaper on a new vehicle because they are supposedly safer.

You must have a different insurance company than I do. Our new GMC is 2x more to insure than our same model older GMC.

It’s always cheaper to repair and drive it. I put a Jasper tranny in my ‘99 GMC a few years ago. It has 293k on it now and running strong. If it ever needs an engine, that’s in my wheelhouse, or if I’m too old to pull it off, it’ll get a rebuilt engine. I use it for my DD too. The Superduty stays in the garage until it’s road trip time.

Thanks for all of the advice everyone. Called around to a couple of places looking for a used one, and nobody local has one. I've got my name in with a couple of them to call me if they get one in.

In the last 15k miles, it's had the following work done to it at the local Ford dealership (by the friend that I bought it from, and he gave me all of the receipts for the work done):

front end rebuilt (new ball joints, both CV shafts, king pin bushings, sway bar bushings, etc)
rear axle/differential rebuilt (seals, bearings, etc)
All electric power lock and window parts replaced
water pump and engine coolant, belts and hoses
New coils and plugs (just 1k ago by me)
New heater core and blower motor

And, as stated above, I couldn't replace it for $2k if I wind up going with a rebuilt tranny. And even if it only ran another 30-60k miles, it'd be worth that to me. The motor is still strong feeling with no noticeable issues. Doesn't even leak a drop anywhere. Completely clean underneath.

Either way, with a kids birthday last week, the other kid's birthday next week and then Christmas, it'll have to wait until after the first of the year before I do anything.

Until then, I'm going to put it in Craig's list and the Facebook marketplace for an amount that I'd take for it as is and if someone takes it for that amount, then great. If not, no big deal. Heck, what do I have to lose?

Some have said replacing a tranny is simple ,but yours has the 4wd drive trans fer case which is about as heavy as the tranny. I have replaced a std 4 speed in a 70 Dodge 3/4 T and a big auto in an old 61 ford station wagon, and I use to rebuild those Fordamatics and Chevy Power glides.
I would not even tackle the Toyota 4WD 5 speed now at my age and bad shoulders like you.

Yep, a 2wd wouldn't be too bad. But the transfer case does add some "strain factor" for me, ha. I put a Turbo 400 with a gear-driven NP-205 transfer case into a '77 Blazer. Talk about heavy.
That was the one that I dislocated my shoulder while trying to stab the thing in. Of course, I already had shoulder problems before that, it was not uncommon for it to dislocate, but that was the first time it did it while holding a lot of weight. Wound up having the shoulder specialist for the Dallas Cowboys fix that one (my doc here was a friend and called in a favor).

If you’ve got a good transmission jack pulling the transfer case is a pretty easy step. Every 4x4 transmission I’ve done I pulled the t-case off first to make it a little easier.