AZJeff

That is exactly what happened on my old axle. Of course, the person who trashed the ball joint bores also splayed one of the “C’s” that the knuckle attaches to, so it was new axle housing time anyhow😠

Cruiser, the key thing you mentioned might be overlooked to ssome degree: "everything else being good" Plain water boils at 212* Put a working 16lb pressure cap on the cooling system, and it raises the boiling point to 252* Add a 50/50 mix, and the boiling point is now 267* If the OP's engine is TRULY overheating (as in getting hotter than about 215* or thereabouts, I would suspect some sort of faiiure to hold pressure as the most likely culprit. (Unless the dreaded head gasket failure that has been thrown out is proven to be a non-issue.)

A rad pressure cap that won’t hold pressure WILL cause these engines to overheat. Nominal operating temperatures are right about boiling point of water, and the combination of antifreeze and the pressure cap will raise the boiling point considerably. Given the cost of a rad cap, I would put a new one on on general principles.

Here is the list of stuff to check whenever and MJ/XJ overheats: 1. clean coolant. 2. good pressure cap or pressure bottle/cap (This is surprisingly a commonly overlooked issue) 3. good viscous fan clutch (its hard to test for this, so if the clutch is old, just replace it) 4. fan shroud (another overlooked, but critical, piece) 5. elect. cooling fan coming on as needed 6. good thermostat 7. a radiator that is free of external debris, and that is free of clogged passages (since it's hard to see inside an XJ/MJ radiator, use the coolant cleanliness as a guide to whether you should be considering a new rad. A neglected cooling system will destroy even a brand new rad in short order. 8. firm/new cooling hoses.

Most guys, when they first own an MJ/XJ with a 4.0, GROSSLY underestimate the amount of tension needed to avoid belt squeal on that belt setup. If you spend any time with these engines, a belt tension gauge is very useful. Lacking that, you can use the “approach to zero” method. this is where you tension the belt to what you think is “pretty tight, but maybe not quite there“. Then you drive the vehicle and load the belt by making sure the AC is on. If it squeals, bet out and add a SMALL AMOUNT more tension. Then drive it again. Repeat this process until the squeal is gone. My engine currently will squeal for about one second when I first kick the AC compressor on when it’s cold. Once it’s hot, the belt is stickier, and no squeal. That’s about perfect….tight enough, but it’s not going to trash alternator or water pump bearings.

I will add my $0.02 here and also discourage you from tightening the box. If you are ABSOLUTELY CERTAIN the box needs some tightening, do any adjustments in VERY SMALL increments, like 1/8 of a turn at a time. Use a paint pen to mark the shaft and the box with a starting reference point. GO SLOW. If you move the screw more than 1/2 turn, it's probably too much.

Cruiser is correct. You might be able to snake a small piece of coat-hanger wire into the nipple on the heater box and loosen any crap that is plugging it up. Then maybe a vacuum with a crevice tool might be able to suck the stuff out the hole. The next level of attack to clean out the drain hole is a huge pain.....remove the heater box, disassemble, clean, reassemble, and reinstall.

I installed Corbeau reclining "Sport Seats" in black cloth, and I sprang for the lumbar support option. These seats are VERY nice, with good firm cushions and some side support. They ran me about $750 for the pair. Not cheap, but well worth it compared to some worn out junkyard stuff with cigarette burns and coffee stains.

The fact is that, for a motor mount to do it's job, it has to be compliant. That means the engine must be able to move (to some degree) independent of the chassis. Rubber is chosen for OEM because it achieves that goal best, but with a sacrifice in terms of longevity. Aftermarket "heavy duty" motor mounts wind up making the compliance component (the rubber/poly bushing) stiffer, and the steel parts more robust. The end result is a strong mount, but one that transmits more vibration. Using polyurethane aggravates that problem further, in that poly is not as compliant as rubber, and thus really makes vibrations get transmitted that much more. In summary, there is no free lunch here. If you want minimum vibes, stick with OEM construction. If you want stronger, there are plenty of choices, but ALL of them will transmit more vibrations into the chassis compared to OEM type.

It has been my experience that most of the leaks are going to be in one of three places: 1. the vacuum hose (and nipple) where the vacuum reservior is located 2. the vacuum hose where it travels under/near the battery tray 3. any of the in-iine vacuum hose fittings/"Tees" that head towards the manifold or the heater box Focus on those first, and then expand your inspection from there. Its not complicated, just tedious. Good luck.

A cracked valve cover won’t torque and seal correctly, and will continue to leak, even with a new gasket. getting a new metal valve cover is a good plan. I have an engine from a 2000XJ in my truck, and it uses a stamped steel cover with special grommets that prevent overtorquing the bolts and squishing the gasket too much. It’s pretty much leakproof with the new silicone gaskets.

Elaborate on what you mean by “cracks where the bolts go in” You mean cracks in the valve cover, I presume?

I would use helicoils. Having fasteners of multiple sizes attach the rocker cover would be annoying if it needs to be removed later. Fixing the screwed up holes will require drilling/tapping. Why not do it with Drill/tap that will allow the use of the standard fastener, which can be achieved via helicoil inserts. Those bolts are 1/4-20, by the way.

There is plenty of room UNDER the cab back behind the seats. It’s going to be a PITA to run vacuum lines back there, and then forward again, but it can be done. you will also need to protect it in some manner if you ever do serious off-road stuff. I would suggest locating it just inboard of the “frame” rail on the drivers side, and add a sort of skid plate attached to the “frame” to protect it.

Agreed......but if you explore IN DETAIL and document the wiring COMPLETELY, you can create your own wiring diagrams to keep it running correctly. it would be akin to making the wiring for a custom street rod. But you need to understand wiring, particularly MJ wiring, well to begin with.

Those brackets are useful if you install a larger/heavier front bumper, tow hooks or not.

And although there is an AC compressor, there are no refrigerant lines connected. (Although it seems to have an evaporator in the heater box.) Is there an condenser in the front of the radiator?

Follow up report: I ran the new lifters on the cam per recommendations given here, and the noise is GONE. The engine sounds like a normal 4.0, which isn't the quietest device in the world, but it no longer has that tick at startup, nor on a hot restart. I think I can declare victory. And thanks to all of you guys who offered suggestions and advice!!

I used fully synthetic Dex/Merc in the AW-4 on my 2000XJ and changed it every 25K miles. The vehicle used this stuff for over 100k miles, with no issues. My current MJ is using conventional Dex/Merc, and I just change it more often, due to the heat issues here in Phoenix.

If you are looking for decent, but not pricey, control arms, CORE 4x4 makes a set for the MJ/XJ starting at about $280.

Yeah, guys, I am up to speed on the torque pattern and the one lower-than-the-rest torque value. I also have the thread sealer needed. The FSM is useful here, for sure. All the head bolts are torqued per procedure, and all the valve train is in, slathered with plenty of “Redline” assembly lube. Tomorrow the valve cover, new spark plugs, and the coil rail go on. if the neighbor is available, I will enlist him to help me install the lower manifold bolts, since it’s impossible to see/feel them from above. Then install fuel rail/injectors, and P/S pump & belt, fill with fluids. Standby....

Gotcha. Makes sense. Got the new lifters installed after coating them with Redline assembly lube. Hopefully neighbor can help me lift head back on to block tomorrow. Then time to install new head bolts and torque them to the God-awful level spec’d in the shop manual!

So run it in at 2k for 20 mins steady. Roger that.

So I decided to bite the bullet and put in new lifters to accompany the (relatively) new pushrods, rocker arms, and rocker pivots that I installed when I put on the new Clearwater cylinder head about 5,000 miles ago. So here is my question: I will be using engine assembly lube on all the parts as put the engine back together. I will also be switching to Rotella 15w40 upon reassembly, and I will add some ZDDP supplement to the oil. But...do I need to do any special 'run-in' procedures with the new lifters on the old camshaft? Back in the day (when I was a young man), the recommendation was to run the engine at 2000rpm for something like 20 minutes to "run-in" the lifters to the camshaft. Is this crucial on the 4.0?

I have a tach in the machine. As far as cleaning lifters, since I have to remove the head to remove/replace a lifter, I would spring for a set of lifters. what other ideas would you suggest?