Brakes didn't change til 89 or 90.

 

Well, according to morris4x4 there are 2 different sizes for the brake shoes.

http://www.jeep4x4center.com/rear-br...-83502385.html

or

http://www.jeep4x4center.com/rear-br...t-8133818.html

The rotors are the same but the shoe sizes aren't.

 

This should be the correct replacement:
http://www.jeep4x4center.com/oil-pre...-56026782.html

 

Those both appear to be the same size- 10" X 1-3/4. I know later XJ's could have 9" or 10" rear brakes, the 10" came with finned drums, the 9" were smooth. I don't know about your year, but measuring your existing ones would confirm the size

 

And how would one go about to measure a break shoe? Is there some special trick to get the measurement or just from top too bottom?

I'll be uploading some pics of the undercarriage later today, am a bit confused if it has been rust protected or if it has leaked A LOT of oil. Also some parts have rusted and well, I need some opinions on if its worth fixing since I will drive this in the winter as well (salty roads).

 

No pictures of the undercarriage but i got a picture of something that's like drenched in oil. Maybe you guys could point me in what the cable does - something with the transfer case?



And here are some pictures of the jeep itself; mind that it "only" cost 700 dollars.






Sucky camera work I know, but I blame it all on the cellphone.

 

Speedometer cable. I would clean out the connector for the oxygen sensor (on the right) and the knock sensor (on the left).

 

Will do. I'm gonna hold of to clean the undercarriage until i get a higher jack to be able to lift the jeep of the ground.

These 2 "things" (don't know the name in english) had quite a bit of oil in them, while the rest of them only had oil "over" the spring. Is that a sign of leakage or just that the oil has gathered there over time?

 

Normal. Not very sludgy for an old engine!!!

 

Thanks, trying to go through most of the engine to see how everything stacks up. I'd like to check the pistons out though - not take them out, just a visual inspection for bad rings etc. I guess I need to remove the next "step" of the engine block right?

 

Just fix the oil leaks, change oil and use a good filter. Run it. Not uncommon for these motors to run 300,000 miles and not use oil.

 

Thing is though, oil on a spark plug isn't all that great in my experience.

And oil leaks, which are the most common ones? Since it looks like it's coming from the right side of the engine - head gasket, oil pan, PS fluid, Brake fluid (Is the master cylinder against the firewall?).

 

Do you have oil on a spark plug?

Here's how to determine the source of oil leaks on a 4.0

　
I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.
Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.
Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?
A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 02-26-2013

 

Yep, I think it was on cylinder 2 or 3 when it took out the spark plugs when i bought the jeep. It was only on 1/6.

From your gold ol' write up eh? But distributor gasket? First time i've heard an electrical component have a gasket...or am I mistaking this for something else?

 

Do a wet and dry compression test if you're concerned about the plugs. Probably fine.

There is a paper gasket under the distributor.