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Going Through a Beater XJ 4.0.

While I was down there installing a new rear main seal on the '88 4.0, I put back the torque converter bolt that was backed out about 1 turn, and torqued it to 28 ft-lbs. Rotated the engine to check the others. All 3 of the other torque converter bolts were 1/2 turn loose !!! That may explain why the knocking went from mild to severe instantly as we drove it home weeks ago. Appears to me that torque converter bolt torque should be a maintenance item.

One piston installed, 5 more to go.

Happy 2018 !!
 
Re: Going Through a Beater XJ 4.0. Pistons are in !!

Just got the other 5 piston/rod assemblies put back in with new tri-metal rod bearings. That should raise the oil pressure a little bit. The mains were .001 undersized and looked good so I left them. Put in a new Felpro rear main seal too. No teflon buttons since the pistons were in excellent condition.

How to get the old hard as a rock oil pan gasket off of the block is going to be a challenge.

After the bottom end it done, then it's time to do the 3 angle valve job on the head. I've decided it will be a lot easier to install the intake and exhaust manifolds onto the head, before bolting all of it to the block.

Once this 4.0 is assembled, I'll pull the distributor to spin the oil pump with a drill, to prime the motor.
 
Torque converter bolts just need to be properly torqued and the threads on both sides clean first. Swapped my AW4 10 years ago, have not touched the bolts since then. But if I recall the problem is keeping the crank from turning while torquing the bolts? Two many job with one tool on the harmonic balancer bolt? IIRC

I agree with Lawsoncl, sounds like it was your real problem. But loose bolts and cracked plates are usually very noisy and easy to figure out.

Is the flex plate cracked?????
 
Torque converter bolts just need to be properly torqued and the threads on both sides clean first. Swapped my AW4 10 years ago, have not touched the bolts since then. But if I recall the problem is keeping the crank from turning while torquing the bolts? Two many job with one tool on the harmonic balancer bolt? IIRC

I agree with Lawsoncl, sounds like it was your real problem. But loose bolts and cracked plates are usually very noisy and easy to figure out.

Is the flex plate cracked?????

No flex plate cracks.

The bolts stayed tight for something like 25+ years. As I tightened them it rotated the crank until the socket was up against the other half of the inspection cover where the starter goes. So they were easy to tighten.

With 4 torque converter bolts, they were definitely the problem.

At least I get new rod bearings and a 3 angle valve job out of the deal.
 
Never have I run into a oil pan gasket that just won't die !! An hour and a half got me all of 2 inches cleared off of the pan, and squat cleaned off the block. My 1000 degree heat gun is the only reason I got anything off of the pan. Tried razor blade scrapers, air chisel, putty knives and hammer, knotted wire brush in a drill. Insane !! So I bailed to go watch playoff games !!!
 
Aircraft paint stripper, pre-soak might have helped a whole lot.

Never have I run into a oil pan gasket that just won't die !! An hour and a half got me all of 2 inches cleared off of the pan, and squat cleaned off the block. My 1000 degree heat gun is the only reason I got anything off of the pan. Tried razor blade scrapers, air chisel, putty knives and hammer, knotted wire brush in a drill. Insane !! So I bailed to go watch playoff games !!!
 
They did not use plastic tanks until much later. 89 and older had OEM brass tanks.
For certain! Didn't help unfortunately.

Today I got about 60% through rodding out the radiator. At least 10% of the tubes were plugged, so far. I think it's the original 1988 radiator as it's all brass with plastic tanks. The bottom 1.5 inches of the center section was covered in debris that might block some air flow. I'll put in a new thermostat too since it's far easier to do with the radiator out of the vehicle. Probably should inspect the water pump too.
 
Started on the intake valves and seats in the 4.0 head. The valve grinder was giving me .0035 total valve run out. Spec is .0015. So I pushed the valve deeper into the chuck and the last 2 intake valves are now between .00075 and .0015. That's good. Sure is splitting hairs ! But worth it !! The intake seats are getting .050" seat width. The exhausts will get .060" seat width. Both will make contact on the top 1/3 of the valve face. Even thinking of back cutting the valves a little for better flow at low valve lift. I'm a big fan of getting as much torque at the lowest possible rpm.
 
That flat file is the only tool I would ever use, short of a machine shop... It is slow as hell, but that is good, as it limits over removal of metal, and shows you with each stroke where the high spots are!!!!

A strong word of warning, number one, I would bolt the Exh manifold to the head, before welding those cracks, as not doing so guarantees warping the manifold!!! Even then it may already be warped.

I have found that file to be an awesome (slow as hell) but awesome tool for getting the Exh manifold faces flat and parallel, but even then, I had to add a copper silicone covered, copper shim on top on the gasket to deal with a huge warped gap between the inner two tubes and the head on mine. Did that in 2007 and it never once leaked or cracked.

8Mud has also done this years ago, he coached me. Lastly do not remove too much metal on the faces as the bolts over lap the intake and exhaust manifolds and if you remove too much metal to get it flat and parallel the bolts loose tension on the manifold spot you sanded down!!!!
 
That flat file is the only tool I would ever use, short of a machine shop... It is slow as hell, but that is good, as it limits over removal of metal, and shows you with each stroke where the high spots are!!!!

A strong word of warning, number one, I would bolt the Exh manifold to the head, before welding those cracks, as not doing so guarantees warping the manifold!!! Even then it may already be warped.

I have found that file to be an awesome (slow as hell) but awesome tool for getting the Exh manifold faces flat and parallel, but even then, I had to add a copper silicone covered, copper shim on top on the gasket to deal with a huge warped gap between the inner two tubes and the head on mine. Did that in 2007 and it never once leaked or cracked.

8Mud has also done this years ago, he coached me. Lastly do not remove too much metal on the faces as the bolts over lap the intake and exhaust manifolds and if you remove too much metal to get it flat and parallel the bolts loose tension on the manifold spot you sanded down!!!!


Files are a great tool for going slow. I keep an assortment for such occasions. The thermostat housing sure fit a lot nicer after some very minor freehand material removal.

As for the welding, I build up, probably over built up, the welding material on the repair. But it worked, except for a pinhole that I'll fix today. Didn't warp fortunately, even without clamping to the head. I'm a big fan of tack welds to help things stay straight. I haven't welded but one time in 2009 since 30+ years ago. So I was pleased, even though it's ugly. We'll see how pleased I stay after the first time the engine warms up.
 
Re: Going Through a Beater XJ 4.0. Intake Carbon Removal !!

After watching some eye opening videos on how to remove carbon from an intake manifold, I finally found my own way using carb cleaner and paper towels. Check it out !!!

https://youtu.be/Gpz16Gy-VJA
 
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