So here's what I have:

YEAR & MODEL 1994 F250
ENGINE 7.3L Turbo - International
TRANSMISSION 2wd 5 speed manual ZF? (not entirely sure if ZF is correct, I haven't been able to locate an ID tag)
REAR AXLE S128C - 3L55 10 2 4A03
MILEAGE 252,781

I bought this truck a couple weeks ago. BAD decision. Made the usual mistake of trusting a "friend" at his word that it was ready to drive....made it 6 miles and it died
After having it towed and repaired ($544) I had my mechanic do a bumper-to-bumper. Oh Boy. Let's just say that it's an impressive list. I can't afford to pay labor rates to fix everything so I'm doing what I can myself. I am going to start by replacing all the fluids from front to back. I've bought the Motorcraft Diesel Oil and FL-1995 fuel filter so far. What do I need to buy for the transmission and rear differential? Brand, weights, gasket part #'s, additives etc. I prefer to use the Ford Motorcraft brand but I am no diesel expert, maybe there's a better (and cheaper???) alternative.

This may sound ridiculous, but I CAN NOT find the transmission dipstick. Before you blast me, know that I'm no pencil pusher. I know my way around equipment but this has stumped me, my left neighbor(firefighter), and my right neighbor(hardware store owner). WHERE THE F*%$ IS IT?!?!?! I would GREATLY appreciate any and all tips, tricks, advice, etc you might have for this truck too. Like I said, I don't know hardly anything about Ford or Diesels. This was my first venture into both worlds.

REMEMBER THIS - When you start listing off things I should do, KEEP IN MIND I AM NOT RICH. I do good just to keep food in my fridge.

 

welcome to FTE.
first off, i moved your post to it's own thread where it will get seen and more responses.

the ZF-5 speed does not have a dipstick. it has a fill plug on the side and a drain plug on the bottom you remove to add or drain automatic transmission fluid.



remove both plugs, and drain out the old. put the drain plug back in and fill the trans with mercon auto trans fluid until it starts to come out the fill hole.
for the rear axle, you will want to use ford XL-3 friction modifier additive: with 90 weight gear oil. southern climate i may go a little heavier on oil viscosity.

as for the other stuff, one thing at a time. we will help you get it back running tip top shape.

what engine do you have, an IDI, or a powerstroke?
Easiest way to check is the 8th number in the VIN a 7.3 IDI Turbo (K) 7.3 DI Turbo (Powerstroke) (F)

 

Fantastic thank you! The engine is the 7.3 IDI Turbo. I've now completed the fluid changes. Next step is figuring out why my odometer/speedometer only wants to work intermittently. I've read it may be the sensor on the rear differential?

This sounds plausible considering it had only about 2 quarts of oil in it and some metal shavings(luckily not enough to panic). The axle vent was clogged too so theres another reason for me to think that's the case. What are your thoughts?

Also once I got going down the road to test for leaks, it started blowing out fuel everywhere. As you look at the engine bay, the front left side is completely saturated. Haven't been able to pin down the source yet. By the way, no leaks on the repairs PHEW

 

fuel leak on bottom of engine, or top?
start engine and look at the fuel pump. see if the fuel is coming out of the weep hole on the pump housing. if it is, than the lift pump is bad.

if the leak is from the top of the engine look at the fuel filter. it may have a hole in it, or the filter gasket may be leaking.
or it may be an injector line leaking.

for the speedo/odometer, your truck uses a vehicle speed sensor in the top of the rear axle to read the tone ring on the ring gear.
check to make sure the VSS is plugged in. you can also change the VSS.
VSS is one of those things i only use ford motorcraft parts for. i have found aftermarket electrical sensors tends to cause problems.

 

VSS itself may be fine, but if there's metal particulate, and it gets between the notches on the tone ring (aka exciter ring, reluctor), that might create a bad signal to the VSS and thus a jumpy speedometer. So get that cleaned up first, pull the sensor and clean off any foreign matter on it (IIRC, it's a magnet, so it may have picked up some of the shavings). Then see what happens.

Transmission calls for SYNTHETIC ATF. Initially, ZF said just any ATF will do, but later, they spec'ed that behind a diesel, it should get synth.

Best way to run these trucks on a budget is to get to know it, bumper to bumper. Remember, this is a completely mechanically controlled engine. Esp. with the manual tranny, there's no computer, and there's no sensor that will keep this truck from running. Makes you wonder where that $544 went. Might be helpful to post an itemization of what was done; that will help us tell you what might be left. Once you get a sense of the workings of the engine, and have a handle on what it needs and what's been done, I think you'll lose that buyer's remorse. "New to me" purchases almost always go through a period like this. If you're into DIY, you'll come to appreciate the reliability and simplicity of these trucks.