KMAPRO

Just to catch anyone up who hasn't seen my other posts referencing my 87 MJ... 4.0 - 5 spd. 4x4..Replacing rear main seal because I have renamed the truck Exxon Valdez. Had to pull the engine to change the rear main seal because the oil pan was stuck to the bottom of the block. I pulled the engine, transmission and t-case all at once. I finally got the oil pan off by taking a 5-in-1 and gently working it around and around the oil pan. Then took a 3/4" wide chisel and gently worked the remaining gasket off - took about an hour and a half. I have also removed the rear main beaing cap. Here is why I am asking if the block is fubarred...I was checking everything out and planning the procedure for removing the upper rear main seal when I noticed that the little steel lip, between the seal and the back of the block, has the corner broken off. Since I have announced, in the past, that I am not a mechanic and just learing as I go, is this part of the upper bearing or is this part of the block? I am assuming - and hoping - it is part of the bearing. Is this critical? Should I replace the upper bearing or will it be OK? It only looks to be the corner of the keeper.

Thanks y'all. Wannabe - That was one of the threads I did find when I did my search prior to posting. As a matter of fact, it was the very first one I read when I did my search. After doing some more research, the group seems to be a bit divided and I would like to know what everyone's real opinion is about pulling everything or undoing the t-case before I pull the engine and tranny out. For the record, I do not have a load leveler. Everything that goes in front of the engine is either removed or moved out of the way, so it is a clear shot. And on another note, sorry I forgot who posted it but, someone mentioned just removing the tranny crossmember and lowering the back side of the engine down far enough to get to the bolts on top of the bell housing. this also seemed fairly simple...My concern here is putting it back together. For the record, I recently pulled and replaced the engine on my 01 Dodge Ram, so this is not my first rodeo...it's just the first time on an MJ and it seems a bit more difficult than the Ram.

OK, did some more searching and saw where some of y'all say it is easier to remove the transfer case from the transmission before pulling it. Which 6 bolts do I need to remove in order to do this?

OK, I did a search before I posted this but I am sure that there is a post on it somewhere and I was just looking up the wrong keywords... 87 MJ - 4.0 - 5spd 4x4 I was originally just going to pull the engine and not worry with everything else, but the two bolts at the top are just a wee it hard to get to with my limited mechanical abilities and knowledge...So, after reading a few posts on here, I decided to just pull the whole thing. Before I get in to what I have done, let me tell you why I am doing this. I have to replace the rear main seal and yes, I know I don't have to pull the engine to do this but the oil pan is seized/stuck to the bottom of the block and will NOT break loose for anything. I also have to replace the motor mounts as the ones I have are totally gone - so I figured why not just pull it - fix it - clean it up - apply a fresh coat of paint and put it back in. Before it goes back in, I will also be replacing the valve seals as well - try to fix my spark plug foul problem. OK, as mentioned, I was going to just pull the engine, so I already have the motor mounts undone - wiring harness removed and all other plumbing under the hood undone. Now, I need to know everything I need to do for the rest of the job. Also as mentioned, I am not a mechanic but I aint afraid to try it either. I am assuming that the rear yoke will just pull out of the tail shaft on the t-case when the engine is pulled. Are there any hoses that I should not undo from the tranny? As in, coolant hoses or anything? What about linkages? OK, in simple terms, please explain everything that needs to be done from the back of the engine to the rear driveshaft please. I know that is asking a lot, but I am frustrated as all get out with this thing right now and need some help. Thanks for any/all help/advice.

Everything still seems good and flexible on my end. The only exception is the wire loom surrounding the wires in places. It just crumbles in my hands when I pull it out. Thanks for the advice and I will make double sure I get all the pan bolts!!!

OK - I am glad I listened to y'all. Did a compression check this weekend and compression was good across the board. Looks like I will be replacing the seals..... I will still need to pull the engine because I have to replace the motor mounts and do the rear main seal. I know I could do the seal with the engine in the truck, but the oil pan is stuck and I have not been able to get it off. I have tried everything that has been suggested in other postings I have made on the subject - still no luck. While it is out, I plan on painting the engine bay and the engine as well. I will start posting pis of the build as I go along in the proper forum.

Thanks Harper - I will do that first then. As a side note, I did talk with my father concerning the problem over the weekend. He said that some of his workers drove the truck and ran it hot. It could very well be something in the head or the valve seals. I will check the seals first and then decide which course to take.

http://www.comancheclub.com/forums/viewtopic.php?f=2&t=24008 I knew that there was just a trick to it...Thank you

Thanks guys. I just misunderstood the explanation the fist time around. Makes sense now.

Thanks Geneovast for the info. If this turns out to be the problem - will it hurt if I make the truck full time 4wd? I am assuming that this is what it would do. Remember, I am using this truck as an EVERY DAY driver. Will I experience excessive wear and tear?

OK here is more info... Truck info: 1987 model 4.0L I6 5 spd manual transmission - I believe it to be the crappy Puegot BA10/5 (I think that is the right info) Transfer Case - I believe it to be the NP-207 because the information I have read says that the 207 was used until 87 and then the 231 replaced it. I don't know if "until" included 87 or not. I don't know how to tell. Front Axle - Dana 30 Rear Axle - Dana 44 I believe this to be a "Metric Ton" package due to the fact that it has the D44 rear end and it is a long bed. What I have already done: I was experiencing oil blow-by as someone mentioned. I have already upgraded to a newer valve cover. I am running a valve cover from a 96 model and the felpro gasket. Other than patching some holes in the floorboard, that is all I have done. Why I am doing this: The valve cover swap helped with the blow-by, but did not eliminate it. I also keep fouling spark plugs at the #2 cylinder (like every other day before I installed a no-foul adapter). For these two reasons, I believe the rings to be bad on the #2 piston. I also have a very bad oil leak coming from the rear of the engine - rear main seal. I am literally going through 5 quarts a week. I am not burning it - I am leaking it..or it is marking it's territory. The engine has a little over 150k miles on it. I figure the cylinder needs a good honing while I have the piston out for ring replacement. If I am doing one of them, I might as well do them all. Since I will also have the oil pan off to replace the rear main seal and the pistons out, I might as well go ahead and replace the bearings while I am at it. When I am at a red light - truck out of gear and foot off the clutch - I hear a slight knock or bump coming from the transmission. If I push in the clutch, the sound goes away. I can only assume this to be the throw out bearing/slave cylinder. Any body got any other ideas as to what this could be? I know 4 wheel drive is not working because I was recently doing some yard work and had to hook to a small stump to pull it up. I shifted into 4 wheel drive, tightened the chain and all I did was spin - rear tires only. The truck is running street tires (hand me down from my father who used the truck as a company truck until he sold his business), so it doesn't take much for it to spin on wet grass under load. Now it does shift down in to the lower gear range, but I get no pull from the front end at all. I do not get any pull from 4 wheel Hi either. I know that the 4 wheel drive system worked when I got the truck, because I used it for similar projects around the yard and never had a problem. I have always had 4 wheel drive trucks, but have never had to work on them because I never had a problem with them. So, I can only assume it is the transfer case. Sorry, but I have no idea what the CAD is... If someone could tell me how to check the transfer case out, I would appreciate it. Now that you know the full story, does it sound justifiable to be doing what I plan on doing? I am open to other suggestions. My goal is to have the truck back on the road within 2 weeks. I am only working on it at nights and on the weekends - and when funds allow. My 01 Ram 1500 uses too much gas to be driving every day - which is why I have the MJ any how.

OK Y'all - It has been a while since I posted on here and I apologize for that but I have been extremely busy with work lately. I am finally getting around to pulling the engine on my 87 MJ (4.0 - 5spd). I am tired of getting better gas mileage than oil mileage. My plans right now (engine wise) are to replace the rear main seal, hone the cylinders, install new piston rings and new bearings. While I am at it, I will also be replacing the motor mounts, as mine are gone, install a new clutch, install a new throw out bearing and pilot bearing. I also need to replace the transfer case because 4 wheel drive has stopped working. I have a couple of questions before I go any further with what I have been working on. I have the engine ready to come out - except for the fact that I still need to disconnect the fuel lines from the fuel rail. I have a disconnect tool for a newer style Dodge but this one will not work for disconnecting the fuel line on the MJ. What type of tool do I need for this or is there just a special trick to doing it without a tool? Secondly, I have fairly easy access to the local Pull-A-Part salvage yard. This is where I plan on getting a replacement transfer case for the MJ. I have already looked through their inventory and they only have one MJ and it is an 86 model. They do, however, have several Cherokees on site. I really don't know a whole lot about transfer cases and was just wondering is there was a particular one I should be looking for. Can some one suggest a good year model to pull one from? Are there distinct marking to tell them apart? Any information will be greatly appreciated. I will post new pictures as soon as I get to a good point in the process so that I can start updating the build up of my MJ. Thanks - KMAPRO

No on the aftermarket exhaust. I have no clue how old the oxygen sensor is. I am betting it is the original one. This was a hand me down truck... As far as the sound when the clutch is out, I haven't checked the fluid level in it lately. I am willing to bet this might be the issue because it grinds a bit when going in second gear when I first start out. After it has warmed up a bit, it shifts smoothly.

First off 87 MJ 4.0 I noticed that when shifting through the gears, except 4th - 5th, I hear a small back pressure pop. Almost sounds like a misfire. Any one have a clue what could be causing this? Next - When sitting at a red light and the truck out of gear, I hear this light knocking, but when I push in the clutch, the sound goes away. What is this?

Well I did get the valve cover changed out and the new Felpro gasket installed with minimal problems. I am a bit curious though, from everyone's postings, I should have had 11mm bolts. The only 11mm bolts I had were the ones where the wiring harness attached - the rest were all 10mm. That rear bolt on the driver's side is a pain to get to. OK, I did check all the tubing and they were all clear. I do still have a leak, but I feel pretty sure that it is a rear main seal. Now, I just need to find a way to get the oil pan to break loose and change out the rear seal. I will try the suggestion above to see if I can get that to work. Thanks to all for their help and suggestions...