Looks like I'm late to the party, but here is my view.
Sorry about the long winded post, feel free to skip to the bottom to read my point.
I personally was raised to take care of my vehicles and drive them into the ground.
It has kind of become a challenge to me, to see how long i can keep them going for.
I'm also very mechanically inclined, some formal training but not a mechanic by trade.
I also have an addiction to tools...
Weekdays i spend behind a computer making $$
Weekends i like to tinker in my garage.
I also find it very difficult to find a decent mechanic, if thinking about
not doing a job i like to interview the mechanic first.
They don't usually like that. some get all defensive and apparently I'm "mean" or something.
Kids today are so sensitive.
The $cost$ of a given job is often not worth it to me when i can usually do it my self no problem.
I view the money saved as reason to have other toys and projects.
I also like to weigh the purchase of a new fancy tool if the job requires it.
I have done very well doing this.
My wife's car (Saturn aura w/3.5) just turned 267k miles the other day. still running strong.
I want to see it hit 300k, wife is already looking for the next one.
I would like to just drop a new power plant into it and keep rocking it, but the wife wants something newer.
So me, my old 03 S10.
I bought it with about 39k miles in 06
I ran that sucker for ever, even had the frame welded up when the control arm mounts started coming off of the frame...
IIRC it's right around 250-270k miles, lots of hard canyon runs hauling a boat, and plenty of offroad fun.
I rebuilt the rear axle a few years ago.
I believe right around 210k miles.
Went after all of the bearings and seals.
Bearing cages were VERY thin and like razor blades...
didn't touch the ring gear, but it looked pretty good.
G80 still works.
Currently the transmission is on it's way out, from what i have gathered the bushing inside of the transmission pump housing is toast.
causing issues with the TCC lockup (already tried to remedy it with a new valve body).
Losing pressure pretty badly.
Ran it with pressures nearly maxed out via hp tuners, disabled the TCC to prevent it from going kaboom and sending bits through out the trans...
My old vette project ( my avatar),
pretty much i drove that thing stock for a good year and decided what i wanted out of it, after doing some upgrades to the engine, exhaust, and I had the rack rebuilt (turn one).
I ended up burning up some clutches and needed to rebuild the transmission.
Local rebuilders = a joke.
I already had a pretty good idea of what was involved.
Bought some manuals, and a dvd and jumped into it!
I ended up with a pretty sweat transmission in the end, learned a ton.
Transmission is fully upgraded, and setup to manual shift but retained auto function.
Manual shifts = near F1 quick shifts
With the engine, massive C6 brakes, transmission, and exhaust system (headers, 3in exhaust, x-pipes, FM40 x2)
The car screams and is an event every time i take it out.
Daily drove it for a while, it gets old lost some of it's "special event".
That project also lead me into EFI tuning.
Overall it challenged me, and i really learned a ton from it.
Back to my S10,
I had planned to rebuild the transmission (4l60e) on the old S10
since i have the tools and knowledge and all..
700R4 and the 4l60E are mostly the same as far as the main drive train parts, and even the 4l60 parts are used as upgrades to the old 700r4.
but with the rona and other projects piling up, current motorhome refurb project has my garage held hostage, and me needing to get out fkn doors finally bought my current Tahoe.
Big selling point was the old S10 Blazer was a pita.
it has the ZR2 package (03).
Result, i go through ball joints, and bearing hubs left and right.
but i did get pretty good at swapping them.
Then i started thinking about a full size.
Knowing that the full sizes are built waaaay better, i started my search.
Decided in the end i wanted to stay with a suv...
Something with a V8 is a better choice for hauling my boat up the canyons anyways.
That old S10 with the 4.3 had to really work to stay free way speeds going up some of the canyon roads, even with out the boat in tow...
Full sizes with the better build quality, i think this is worth keeping on the road for longer.
So i ended up getting one with higher mileage, right at that 170k mark.
I would never have guessed this truck had that many miles
Not a drop of oil is leaking anywhere.
Also no signs of an oil leak in the past.
Amazing!
My point being,
I think these trucks are worth keeping.
However paying someone else to do the work may get a tad $$
As they age major things may need to be done to them.
But it sounds like you have it figured out.
And sorry about the long winded post, starting my day, I'm feeling motivated!