I'm almost 67, and always thought I was in pretty good shape for that.
The other day, I was changing the serpentine belt and repacking the front wheel bearing on my '06 F250.
The belt only took a couple hours of working off a step ladder being bent double, and/or laying
across the top of the engine reaching down through the about 1/8" gap between the engine & the razor sharp fan.
The two bolts holding the caliper bracket--- Whew!! They come in from the backside, and had some sort of goo
on them that required 3-4 strokes with a 8 pound hammer to make them turn for each 90 degrees.
And yeah, they're fine threaded and seemed like they were about four feet long.
Driver's side- not too bad since I could swing down.
Passenger's side: Hammering UP for about an hour on the breaker bar & socket while all hunched up in the wheel well was different.
Then, taking off the rotor & hub-- they're one piece, and must weight 50-60 pounds.
I remember when this was just another quick, 'no big deal', evening project. Not any more.
It about killed me..... I'm sore in places I didn't even know I had.
I was going to wimp out and take a couple of aspirin,
but it's more fun to hobble around, moan & groan, and complain all day.