Scott91370

Looked like the rear main was leaking on my 93 so I decided it would be a good day to take care of it. Drained the old oil, pulled the pan then the bearing cap. The studs came out of the block instead of the nuts coming off - didn't make me happy but not a huge deal. Gently pulled the bearing cap off noticed the bearing did come with it. Didn't think much about it especially after looking around and seeing the mess wasn't too bad and it probably wasn't the seal leaking after all - too late now, I'm already in there. I swapped the gasket on the cap went back out to the truck to do the inner half and as I figured the bearing was up on the crank. Got it out and:

Not good news - OBVIOUSLY. Looks like the first set of brakes on my nephew's truck when he came to me saying it was making a little noise.
I can feel some grooves on the crank so that's definitely gonna cost some money, even if this is the only bearing messed up.
Question is, since this is an off road only rig, would you put it back together and run it until we all know what's coming happens or, UGH, pull the engine and get a new crank & bearings?

Man this was supposed to be a good day!!! Almost as bad as getting fired on your day off.

tech

If that's a crank bearing I would think the cam bearings would be just as bad , how's the crank look ?

Scott91370

The crank looked ok but with my fingernail I could feel some grooves. If it wasn't a crank I would say they were very small but I know small might as well be large.
I mean, I wanted to, at some point, redo the engine but not before I even had the chance to take it to the trails and tear something up first.

I don't know much about these engines but why would the cam bearings do the same?

Scott91370

Also, do all of the 4.0l come with the girdle? I've watched a couple of videos on changing the rear main they they had it but mine does not. Makes me think this is not the first time it's been opened - well that and the blue FelPro oil pan gasket.

tech

The cam bearing are using the same oiling system , if the crank had a oiling problem the cam had the same , i would hate to see you go though all the work to fix the crank problem and still have low oil pressure .

DFlintstone

I suppose in your shoes I'd pull at least one other main and have a peak, then Plasaguage a couple of rods. You will get a better view on things. Even for a "hill truck", you might not want to throw a rod and trash the block. Once changing an oil pump in a lady friends Ford, I went ahead put all new inserts in it. Had the pan off already and it was only about $30 for the bearings. (you check the back of the insert you know, nothing or "Sdt" means they are not oversized, or there might be a .10, .20 ect for oversized). In any case don't get things mixed up! (caps same way, on the same journals).

Scott91370

That makes sense. You mention low oil pressure. I was seeing 20psi at idle before and after I pulled it apart. What is normal?

The bearing I had out was stamped .001 A-F and something else. The bearings are cheap but since the crank is also scarred I'd rather grab a replacement engine and swap it in versus just replacing bearings. There is one a couple of hours away that is said to be running good when pulled. It is the engine and AW4 transmission for $600. I don't even know if that's a good price. And if it is I don't know how direct of a swap it is since it is a 1989 engine going into a 1993 - sensors, connectors, etc.

To be honest, I think one of the previous owners (who turned out to be electrical hacks) probably did some work inside this engine - it has one of the blue FelPro oil pan gaskets. I could see them having done the rear seal at one point and messed something up, there isn't much to doing it, and causing this. I honestly think the rest of the bearings will be ok but didn't think to check them before buttoning it back together. I had to get it out of the driveway so I just put everything the way it was and moved it. But let's say I open it back, pull the front main and all 6 rod caps to find no damage. Would it be as simple as dropping the transmission, pulling the crank and getting it turned, new bearings and buttoning it back up? Heck, I guess even if all the bearings are bad it wouldn't be any more cost or work either. Man, this bites!!

I wish there was a Thanks button here. I appreciate the input from everybody!! And if anybody wants to swing by to let me know!

DFlintstone

Gotta go light or whole hog in my opinion. It's a difficult slope. In "days of old, pulling the head, (and gettin it OK), then doing rings and rods for another 75K or so made some sense. Anyway turn the crank, well then how about the timing chain and cam bearings?, well heck, an oil pump too...might as well make the head bulletproof since I'm in so far. Gosh, now probably let's ridge ream and hone, or bore it and go with oversize pistons. Booger that, might as well go with a full overhaul and make it a stroker.

I wouldn't mind paying $300 for an engine or transmission if I needed one. I suppose you could sell an extra AW-4......The engines will swap fine I'm sure, there IS some stuff. Basically you want to have all the sensors match the year of your puter, which you can. Newer trannys have different sensors than the earlier. Probably there is a way to make it work even if 89-93 are different. (lot's did change around 90). At some point the spline count changed on something, output to the transfer case in 96?

You are going to need more help than I can give you there. I'd bet there is reliable engine swap info at cruiser54.com ,also I have a little mess if Renix info in the link in my signature.

Scott91370

I have started scanning cruiser54's stuff. I'm just so new to these and of course with the changes in the early to mid 90's I'm getting a lot of mixed info on what will/won't work.
I was actually thinking that the 89 motor attached to my trans would be the easiest that way I don't have to worry about anything with the trans causing issues. And with both being pre OBD2 I was hoping the sensors wouldn't be too difficult to figure out or even be different.

Man this is no fun. Back to searching and seeing what may work. If this wasn't just a toy I'd build a new engine that would be good for another 100k, but explaining the $2000 bill to the wife would be rough.

SatiricalHen

In regards to the "nuts not coming off" there are actually no nuts and studs it's a bolt with a smaller "stud" on it. Also, the girdle was not on all engines. My 87 didn't have a girdle, so I pulled one from a later model 4.0 because I was already in there doing everything else. As far as 89 engine fitting and this or that engine fitting. The renix 87-90 the head will not line up with your intake because of the intake and exhaust ports, but you can swap the head of your engine onto that block. The 91-95 engine are drop in same head and everything (not sure if there were any sensor changes really, but rule of thumb is use the long block keep all of your sensors and accessories just in case), the 96-99 had a different head and only some have the temp sensor hole at the back of the head for the gauge or dummy light, but this can be worked around, and 00-01 are not desirable because of their head cracking, but would work in your vehicle technically. Or in my case I have an 87 block with a 93 head, with a 99 intake with a comp cam. It's all cobbled together. Jeep 4.0s are kinda like legos almost.

00t444e

They started putting girdles on them around the 96 model year.

Scott91370

Well, with the info from SatiricalHen & cruiser54's pages I think I will pull the trigger on the 89 engine and trans for $600. Maybe sell the trans to recoup a few $$. Swap my head over and do the install. Then disassemble the current engine at least enough to see if anything else is wrong with it. If not and the cost to freshen it up isn't too high I'll do that to have a backup.


Thanks everyone for your input and please, wish me luck!!

DFlintstone

Makes sence to me, (selling the "new" trans"). There is no need to swap heads, you just need to use the right gasket when you put your manifolds on the 93. (probably the Renix gasket, but check that). It's actually not complicated. The 93 should have the hole for the knock sensor, and the gauge/light sender is still top left on the head. Any issues you can always come back here or contact Cruiser. Might as well go get some Liquid Wrench or something and start spraying bolts now!

Turbo X_J

If the "good running" engine is just laying there it takes 5 minutes to pull the oil pan and a couple of bearing caps, no reason to waste money on another boat anchor.

Scott91370

Mine is the 93 so I would be going to the 89 engine.According to cruiser54 I can eave the head and use my intake manifold. I might have to go back to the 93 manifold - I just put a 96 manifold on my current engine. Waiting to hear from him if my current exhaust manifold (which I had to replace because mine was cracked).

Good point. I will definitely ask him before the drive down.