$400 4.0 rebuild

[Mike Honcho]

Bought this 1998 XJ about a year ago, it needed a clutch and I got for $1800 which seemed decent for a rust free 5 speed jeep.

Wife was driving it the other day and it developed a loud tick. Jeep has 246K miles so I decided to do an in-frame rebuild. Ordered Pistons, rod bearings, lifters, pushrods, rocker arms and all gaskets. Spent $179 for a piston/ring kit on amazon and another $175 at Rockauto for the rest.

What I found in the oil pan.

#6 piston dropped a skirt. The head and cylinder walls look great for something with 246K miles.

Parts came in the mail

Removing the old wrist pins was easy enough with some heat and my HF press.

 

[Mike Honcho]

Installing the new wrist pins/pistons was challenging. I froze the wrist pins and pre heated the rods to 400 degrees in the oven. When installing the wrist pins all but one didn't seat all the way.

After admitting my failure I called local machine shops and they were all back logged 1-2 weeks before they could install the wrist pins properly for me. I found a youtube video of a guy with rod holder to press the wrist pins out. I busted out the plasma cutter and some scrap steel and made a copy of the tool in the video.

The rod holder worked really well. I would recommend making a tool or just planning to have a shop install wrist pins.
Cleaned the head and the deck with some blue scotchbrite pads. Honed the cylinders to remove the glaze with a 180 grit ball hone.

Installed the pistons in the block. I replaced the rod bearings even though they looked very good. Not sure if you can reused bearings? they were cheap so I figured why not.

There are a ton of head gaskets options. I saw good reviews on the Victor Reinz HG so I went with that one.

The FSM says you can reuse the head bolts one time so I did not replace them. Installed the head and torqued to spec. I had to grind a socket down to fit the torque wrench on bolt # 14 the LH/AFT bolt. I installed the new lifters, pushrods, rocker arms and valve seals just because they were very cheap and I figured why not.

 

[fl0w3n]

Nice, how was the access from the bottom? Would you do it again in-frame? Did you use a cherry picker for the head?

 

[Mike Honcho]

I closed up the rest of the engine/ intake manifold and topped off the fluids. I primed the engine with the starter a few times with no plugs until I saw positive oil pressure about 35-40 psi. Plugs back in and it fired first crank. No noises, ran great. I have 3 jeeps with 4.0s and this is the smoothest/ quietest one now. I put in mobil 1 full synthetic as it was cheaper than walmart oil. Going to run it for 100 miles and do an oil change.

 

[Mike Honcho]

Nice, how was the access from the bottom? Would you do it again in-frame? Did you use a cherry picker for the head?

Very easy access after you remove the girdle. I would do the in frame again 100%. There is no reason to removed the engine unless you want to remove the crank or the cam. The head weighs about 60lbs. I lifted it off and handed to the wife and we both set it down on the bench. Not really heavy enough to use the cherry picker IMO. This would have been a two day job if I didn't dick the dog on the wrist pins.

 

[fl0w3n]

Sweet, nice work

 

[Lbhsbz]

you know how I can tell your wife was the last one to drive it?

 

[Mike Honcho]

you know how I can tell your wife was the last one to drive it?

Beats me?

 

[RunningProblem]

Empty gas tank.

 

[Mike Honcho]

Empty gas tank.

Good catch ! Lol

 

[Mike Honcho]

275 mile update. Running good with no issues. Changed the oil and no metal/debris that I could see.

 

[CJ3BL]

Nice work!!!👍

 

[Weasel]

What did you use to install the pistons? I've having a hell of a time with mine and tried 2 different tapered install sleeves and the piston hangs up on both and wedges crazy tight in the taper section. It's been bored but all the numbers look right and match up. Need to get working on mine.

Good thread!

 

[Lbhsbz]

What did you use to install the pistons? I've having a hell of a time with mine and tried 2 different tapered install sleeves and the piston hangs up on both and wedges crazy tight in the taper section. It's been bored but all the numbers look right and match up. Need to get working on mine.

Good thread!

I've had one of these for years...

Otc 4838 $67.99 Piston Ring Compressor Set, 6 Pcs. | Zoro.com

Order Otc Piston Ring Compressor Set, 6 Pcs., 4838 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

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After you get it on the piston, keep squeezing it and knock around it with hammer to get a couple more clicks...then it works great

 

[Mike Honcho]

What did you use to install the pistons? I've having a hell of a time with mine and tried 2 different tapered install sleeves and the piston hangs up on both and wedges crazy tight in the taper section. It's been bored but all the numbers look right and match up. Need to get working on mine.

Good thread!

This is the tool I have. Got it at oreilly/autozone I believe. You install the tool on the piston / compress the rings then simply tap the top of the piston into the cylinder with a hammer handle. Not much force is required to slide the piston into the cylinder.