Keeping my 2nd gen alive for as long as possible

[Brain75]

In the course of the 2 1/2 months rehabbing the exterior (paint, bodywork), I have enjoyed reading many threads here. I also have come to know my little truck better than any other vehicle I had before. Knowing the weaknesses and paying attention to the specific subtle clues you know to keep an eye on are probably the biggest thing to keeping a vehicle alive.
I didn't know of specific weaknesses, nor did I spend the time to research in my other rides (though I came to find out my '89 FWD was tire eating POS and my current '06 GM likes to chew up batteries).

So 2.9L are notorious for cracking heads, that is something repeated often, as I come to understand it mine might be a little better than the older 1st gen ones (head redesign in 1989).

The M50D-R1 has a weakest link in the slave cylinder, no fix for that other than fluid change, keeping an eye on it and buying a better slave when you do pull the trans for clutch+slave.

Other than that I haven't seen a lot of complaints about specific 2nd gen, M50D, or 2.9L weaknesses.

I was thinking about a list of preventative, better to do it now things I should do before I really put it into "regular" service.

I found the 4.0L radiator swap advice (put a thick radiator out of a 4.0L explorer with AC infront of the 2.9L for better cooling), coupled with the lower thermostat.
(reason, to keep from cracking the heads on the 2.9)
swapping my open 7.5" 3.73 3.45 rear end for a factory LS 7.5" 3.73 3.45 (only really thought of this due to the fact one just showed up in the yard)
(reason, Colorado snow... it's just a fact of life driving on snow. The rest of the family refuses to drive it in winter, it just stayed parked 55-60% of the year. The big doink in the rear of the box was my fault cause I drove it in snow when I had to have a truck for something.)

The motor has a fair bit of clickety clackety ticking away, but even in '96 when it became a family possession it did that and I was told that "2.9's just do that".

At some point the muffler rotted out and my mom's boyfriend put a new exhaust system from the muffler on back into it (ordered aftermarket on amazon "no weld" kit and just bolted it up).... as a result you don't want to load it past 60% full or the exhaust touches the axle and twists the whole exhaust pointing the output directly at the side of the box. I added a short stainless steel tip to it, not for looks, but to get the exhaust out past the body instead of cooking the lower part of the box - crappy cheap kit.

The slave (or trans) has some more than noticeable difficulty getting into Reverse, and after discussion on a thread here where I helped someone out I went and really felt for the synchros in every gear - turns out there is a subtle slight stiffness going into 1st I just wasn't noticing until I really looked for it.

There is a sizeable oil leak around the filter adapter, I have done absolutely nothing about that during paint and it didn't leak 1 drop as long as I was rolling it back and forth in the paint booth (by hand, engine off), once you start it though the high pressure makes it show up as a piddle in just 5 minutes of idling.
Oil looks beautiful, but with a leak as bad as it has I think a guy is gonna be topping it off all the time so it better look pretty... fixing that is scheduled for the same time as the first oil change.

Assuming the PO (family member) is being honest, and there is no reason for them to BS me, I am still close to them. And assuming they haven't forgotten anything, there has been very little done "since it didn't need it".
Tires/Brakes/Fluids/usual manintenance and the "needed it" list is Exhaust and Clutch.

I am sitting at 110k, and you can assume nothing else has been done. Nothing, like not even plugs and belts. Though it runs like there is no vac leaks or any other issues. Oil pressure sits exactly on M in norMal pretty much all the time after starting. Coolant temp rides back and forth between N and O in NOrmal.

What other things would you guys suggest?
Can you replace the 3 rubber vent plugs with steel in the top of the trans without dropping it?

I am thinking a coolant flush, and since that is on my mind just combining it all into a weekend project - 4.0L radiator, new thermo and coolant.

1) 4.0L radiator, lower thermostat, flush and fill new coolant
2) swap rear ends to a limited slip.
3) Fix the oil leak @ 90 degree adapter.
4) Transmission fluid flush and refill -switch to synthetic (hope it helps me baby along the slave cylinder issue as long as possible).
5) Clutch fluid flush (with a new clutch 10k miles ago I am really just looking for bandaids to keep the slave issue tolerable till I have to HAVE to do it or I can do it and the next clutch together)


What else would you guys suggest.
Would you seafoam a perfectly happy but clickety clackety 2.9L ? ( watched the video Jim sticky'd)

Any other suggestions to increasing MPG would also be happily received, I haven't driven a lot of gas guzzling monsters... my 1948 gets 6.5-8mpg full, empty, with a tailwind, headwind, cruising or idling, it just sucks to fill up that 33 gal tank and I want that to be my ONLY wallet killer, that is bad enough.

 

[sgtsandman]

You pretty much have it covered. If road salt is used there, get the under body and frame sprayed with fluid film. The stuff sprayed with an air gun is thicker and more resilient than the rattle can stuff but either works. There are videos on tricks and tips out there if you do it yourself.

Mercon V transmission fluid is a full synthetic. It's what my transmission likes best and lasts the longest but others have been happy with aftermarket or going with Dex/Merc that uses an older Mercon formula.

Speaking of transmission fluid, your power steering system probably uses it was well. Verify that first but it wouldn't hurt to change that too. I empty the reservoir on my 2011 every three years and refill it along with the brake system and clutch system flush and bleed.

When you go to do the radiator and flush the coolant system, reverse the heater core hoses and make sure the heat regulator valve is open. This will help keep the heater core clog free. Repeat the hose swap every time you change the engine coolant. Three years is the standard for doing that.

As far as the transmission vent plugs, some have said they were able to change them with the transmission in the truck. Only do it if it needs done. If the current caps aren't leaking, leave them alone.

For the filter adapter, there was a discussion a little while back about the seal for that as far as part number, where to get it, and so on.

 

[alwaysFlOoReD]

IMO, the lower temperature thermstat does nothing for cooling. It opens at 180° but the coolant will get hotter than that. That temperature is the coldest the fluid will get, not the hottest. Use what the factory specified as that is best for engine and transmision.
The radiator does the cooling. The thermostat regulates how cold the engine can get when running, not the maximum temperature it gets while running. And too cold in winter can affect engine deposits, auto trans clutches ,and maybe other things i haven't thought of.