Opening up the engine

[PaulS]

I'm about to remove the L134 from my frame.   Everything else except the axles/springs, and power steering unit are already off, so the frame is almost ready for cleaning/derusting and painting.

As for the engine, I am going to clean it (externally) and paint it.  I'm going to pull the water pump for a possible rebuild or replace.  Beyond that, the engine seems to be in good shape.  All cylinders show 110-120 psi compression by the time they hit three or four compression strokes.

Should I be thinking about doing anything else while I have it off the vehicle?  It probably doesn't have more than a couple thousand miles since the engine was last rebuilt--but that was around 1988 or so.  I'm tempted to pull the head, pan, and valve cover to have a look inside, but that would mean ordering new gaskets.  But maybe I should be replacing gaskets and seals anyway.  Besides, I'll have to be ordering at least the water pump gasket , so it's no big deal to add things to that order.

What would you do with an engine like this if you had it out of your Jeep anyway?

Next question:  to mount the engine on the stand I have, I'll have to pull the flywheel off.  Is that something I want to avoid unless necessary?  Or do I just want to make sure it goes back on the crank in the same position it came off?

Thanks,

-Paul

[athawk11]

Hi Paul,
Your compression numbers are very good.� I wouldn't tear into the engine, but if you find obvious leak points, I would address them while it's out.� I would avoid pulling the head unless you have a head seal leak. Too many stories about busted studs.

The flywheel can only be put on the right way, or 180 degrees off.� Just mark the existing position before you remove it.� You'll be fine.

The one thing I would definately do while you have it out is replace the clutch and throw out bearing.� There will never be a better time...unless you know they are nearly brand new.

I've not done it, or tried, but have read that rebuilding the water pump will require some 'machinery' to clean up and press it back together.� I opted to replace my pump, but kept the original for a potential future rebuild project.� If you do rebuild it, post some photos and information on your process.� I would like to know how it goes.

Good luck.

Tim

[Macgraham]

Might be a good idea to remove the oil filter element. If it has a metal cover, cut it and spread out the filter paper under a good light in a clean place. A magnifying glass may help but usually if something nasty is going on the metal will be easy to see. If it is clean, less concerns.

[1oldracer]

Hi Paul, I was just looking over your posts and I remembered something that one of the guys said when I was first asking about removing the flywheel - remove the nuts holding it on but leave the two big ones loose but still on their bolts to keep the flywheel from ending up in your lap or crashing to the floor when it pops off as it will probably be a lot heavier than you expect it to be.  Good luck

[Matto]

You should look closely at your ring gear to see if the face of the teeth, facing the front of the motor are ground down in spots. Usually in two areas of about 10 teeth each, 180' apart. If you find this, and the other side of the ring gear is good, you can remove the flywheel and remove the ring gear from the flywheel and flip over. This link to the 3B page shows how to change a ring gear.
http://www.film.queensu.ca/CJ3B/Tech/EngineRebuilding.html

[PaulS]

remove the nuts holding it on but leave the two big ones loose but still on their bolts to keep the flywheel from ending up in your lap or crashing to the floor when it pops off

Ha!  I read this 20 minutes *after* I removed the flywheel!

But I had indeed left a couple of nuts in place when I was trying to get the thing off.  I had read similar advice on another forum in relation to removing the brake drums on my old Ford tractor, and when the flywheel didn't just come off by hand, that advice sprang right to mind.

But you said "two big ones"--all six on mine were the same size.  (The nuts, that is.  There were two tapered bolts.)  Is that not right?  BTW, are the bolts supposed to be able to rotate?  It was good that I could just fit a crescent wrench behind them to hold the back side still.  Note that I have a 2A engine, if that makes a difference.  Actually, I think it's one of the engines made for the military Jeeps and bought back by Willys after the war (and used in 2As)--based on the casting # and the location of the S/N above the water pump.

-Paul

[PaulS]

You should look closely at your ring gear to see if the face of the teeth, facing the front of the motor are ground down in spots. Usually in two areas of about 10 teeth each, 180' apart. If you find this, and the other side of the ring gear is good, you can remove the flywheel and remove the ring gear from the flywheel and flip over.

I took a quick look, and the wear seems pretty even.  (I'll take a closer look later.)  The teeth are not symmetrical, though, so it looks to me like it's worn all the way around.  Is this still worth flipping the ring gear for?  Does flipping it create any balancing problems?

Thanks,

-Paul

[bwtufts]

The flywheel position does not matter unless you use the marks on it (through the peep-hole) for timing. (Relevant to earlier 3A's)

I wouldn't mess with the head if it isn't leaking.

If I didn't know who rebuilt the motor, I would pull the pan and valve cover to check everything; You might as well adjust your valves while it's out too. Check for any extra play on the rod bearings and your end play on the crank.

If your engine does not have the timing marks on the timing cover I would suggest doing something like this http://www.thecj2apage.com/forums/diy-timing-pointer_topic12750.html as it makes timing the motor a breeze!

[1oldracer]

Hi Paul, I may have given you a bum steer on the relative size of a couple of bolts on the flywheel.� 1.� I was thinking about my flywheel which is from a M38 and may be different from yours.� 2. I'm not kidding about the "old" part of my forum name�

[Matto]

I took a quick look, and the wear seems pretty even.� (I'll take a closer look later.)� The teeth are not symmetrical, though, so it looks to me like it's worn all the way around.� Is this still worth flipping the ring gear for?� Does flipping it create any balancing problems?

The teeth on the ring gear may have rounded corners on one side to help the Bendix gear mesh with the flywheel. Looking at my four spare flywheels one has slightly radiused teeth on one side the other three have square cornered teeth on both sides. You should only change it if you have obvious wear spots. If the motor was recently rebuilt they may have replaced the gear.
� I've seen many of the gears flipped and have not heard of any balance problems. I flipped one on my F head motor in March and it's amazing how much bigger the hot gear is than the cold flywheel, you'd swear it wouldn't shrink that much as it cooled.

[PaulS]

Now that it's up on the stand, I took some shots.  Seeing where the oil accumulation is, are there any seals or gaskets you'd be going after?  Or is this normal seepage over 20+ years?  I do wonder about the huge mess under the oil filling tube--is that just spillage during filling, or is oil coming out that tube somehow?

Thanks,

-Paul

[F Bill]

Valve tappet cover leaks, front and rear main seals leak, and your small hose on the oil fill tube appears to leak.
The oil fill tubes normally loosen up over time where they enter the block, and leak there. You;ll need to expand it slightly (With something like a socket) and use sealer there upon installation.

All that is pretty much normal for a 20-30 year old set of gaskets.

[Macgraham]

Looks like the crud is heavy near the top of the oil tube. Maybe gasket issues with the dipstick cap and some blowby?

[Carls_jeep]

You have the rear freeze out plug leaking, the head gasket leaking and all the other issue pointed out.

My opinion is to completely strip the engine down, have the block and head hot tanked and both magnafluxed for leaks. Have the machine shop recommend what to do for a rebuild. You can have them rebuild it or have them do the machine work and rebuild it yourself.