I'm sorry bogart219 for my last post sounding too harsh. It was a general response to anyone giving up on their car.
My sister wanted to do that with her 2007 Jeep Unlimited last year. It had the well known "death rattle" and the past year the track bar had been replaced. I finally got details from her and learned that nothing had been replaced before, and the truck was at 185k. The shops(alignment shop too that I recommended) she had been to did not suggest replacing ball joints or anything else(until the Firestone place that said it was the track bar(and charged her $900 for that and an alignment)).
I spent hours doing her BJ's, and that didn't fix it. I did the TRE's(4), no joy, then the pitman arm and steering box. I was tired of working on it and she wanted to trade it in the same day, take whatever loss(bad idea, those things are really expensive used). I then did the rest of the parts, plus another track bar(aftermarket this time). New control arms, new hubs, four new TRE's(the others died from the vibration fast), and the truck is good now. The point is leaving a vehicle untouched until something breaks is a bad idea. It costs more because there are so many parts with enough age that they all could need it. You should do a little at a time as you learn what parts are the oldest. That's what the OEM maintenance schedules are best for, they tell you what you should concentrate on, and when.
For the SOHC 4.0 Ford, it has so many parts in the valvetrain, that neglect of any kind is not wise. Cranking the engine to get oil pressure is good, fine, but the oil quality is critical. People forget that, and nobody considers the air filter. The vast majority of oil contaminants come through the air filter, and past the pistons. A clean air filter and dino oil, is better than a bad air filter and synthetic oil. Think about that, and then start buying air filters more often, the best you can get.
The front timing parts of the 4.0 SOHC are more likely than the back to let go, it seems like about 5+ times more likely. If the mileage is over 150k, the rears are on borrowed time, all depending on the condition of the oil through that time. I did the fronts of my 99 truck when I got it at 77,450 miles, plus the rear tensioner. Now at 153k miles the trans is out, it's time to do the fronts, and rear timing cassettes again. I know that's not good to have to do for an engine, major maintenance every 75k miles, but that's the reality of the 4.0 SOHC, past that is good fortune.
FYI, I had Amsoil synthetic in my 99 SOHC the last time I drove it. It was the Signature series, good for 15k or more miles. I had no oil losses, so at 9000 miles it was still virtually full, and almost clear. How could that be, think about it? The air filter I used was an aftermarket Amsoil, a universal cone thing that fit inside of the aftermarket air cleaner(Volant). The oil stayed relatively clean due to the air filter. Now the rest of the story; I check it three weeks later to enjoy seeing the transparent oil again. I was disappointed, it was pitch black. I was puzzled for a few seconds, and then I decided to remove the air cleaner lid, to see the filter. My special air filter was laying in the bottom of the air cleaner, it had fallen off. The clamp wasn't tight enough, it was the first time I had put it on, and used that special oil. I haven't used that level oil since because my other cars use too much oil, and that oil was $9 a quart. But it's worth it if you have no oil losses, and a high end air filter. I'll use it again when I get my 99 transmission fixed soon.
