What is the most important tip you'd share with MJ owners?

[1988gecko]

Make sure the frame is solid

[HOrnbrod]

Not the most important, but...........

 

When removing and installing the MJ dash bezel, slide a piece of wax paper between the bezel cutout and the steering column. This will protect both the bezel and column and prevent scratches.   :thumbsup:

[jpnjim]

 

If you have the tranny/tc out,put them back in as a single unit. The top 2 bolts holding the tc to the tranny are a real PITA to install with the tranny in the truck.

 

 

Or use about 3 ft of extension!  I installed mine seperate and while it was all 4 tires (no jack stands), easy easy!!!

 

I cut a 9/16 combination wrench in half to reach those upper T-case nuts.

& slip a second wrench around the stubby end for torque.

 

I use the box end of the cut wrench for initial loosening & final tightening,

 

and use the open end to spin the nut quickly when it's loose.

 

It's really not that bad.

 

Edit,

It was 22 years ago,

but I can still remember exactly what bench pressing the trans/transfer case combo in and out of my 87 Cherokee twice in one month feels like.

Spinning the driveshaft with my feet to line the input shaft up into the clutch disk  :ack:

 

 

Once to do the clutch, and again when the slave cylinder went a couple weeks later.  :fs1:

 

I wasn't too dumb to do them both at the same time,

just too broke. :(

 

I don't think I could do that anymore so I do the trans and transfer case seperate now :)

[gogmorgo]

Not the most important, but...........

 

When removing and installing the MJ dash bezel, slide a piece of wax paper between the bezel cutout and the steering column. This will protect both the bezel and column and prevent scratches.   :thumbsup:

A great idea. Probably also makes it easier to slide the bezel across the column. Every time I've pulled one it's been a wince fest hoping this isn't the time I break it. They're pretty brittle when you're pulling them apart outside in the winter.

[Minuit]

On 5/12/2017 at 12:37 PM, HOrnbrod said:

Not the most important, but...........

 

When removing and installing the MJ dash bezel, slide a piece of wax paper between the bezel cutout and the steering column. This will protect both the bezel and column and prevent scratches.  

 

Ooh, that's good. Never broken one but there's been some white knuckle moments for sure.

 

Here's another tip for us automatic folks:

 

If you can get it off without breaking it, there's usually no need to go buy a new neutral safety switch. They typically don't "go bad" per se - the most common problem is dirt/gunk/petrified grease inside of them causing the contacts inside to make poor contact. They can be taken apart and cleaned pretty easily. Just make sure you don't lose any of the small springs and contacts inside of them. Typical symptoms of a dirty NSS include intermittent or non-working reverse lights and no-crank no-start that is sometimes rectified by wiggling the shifter. You may notice that these symptoms get worse with time.

[Sugarfoot]

On 1/20/2009 at 9:39 PM, Akula69 said:

#1 - Always check the body grounds first when strange electrical problems start appearing.

 

#2 - If it won't start check the CPS (crankshaft position sensor) first.

.

[Minuit]

Here's a stupid one that happened to me a week or so ago...

 

It's possible to plug in the blower speed switch "half way" so that only one set of contacts is actually plugged in. If you do this the fan will only work on low. Don't be a dum dum like me and put your dash all the way back together just to have to take it back apart again to plug the stupid connector in properly.

[Lftrn97]

So after two years of dealing with periodic overheating I finally stumbled on a solution that has worked...REPLACE THE COOLANT BOTTLE CAP IN YOUR  RENIX CLOSED SYSTEM WITH A VOLVO CAP PART #9445462.   get it from the volvo dealer,best $40 i've spent.

[Kickin’Chicken]

Dang! My tip would be to not read this thread. I'm more worried now than a long-tailed cat in a room full of rocking chairs. 

[shrapneltyphoon]

If you buy an 86 make sure it's a I4 and not a V6.  Or atleast have a engine ready to swap in.

[JMO413]

1- Join this site and fill out your profile and signature

2- Bookmark Cruisers site, then get busy

3- Find a good wiring diagram and keep it handy

4- Don't give up

[WyoCherokee]

always have a parts rig in your driveway..or 3.

[specauto]

Old thread. I actually have a couple things to add,  some of these may be duplicates:

 

4.0L tips

 

1) When you repleace the rear main seal, make sure you are VERY cautious about driving out the top part of the seal. The crank surface is very soft and if you poke it with a hardened punch, it will damage it. Invest in a Brass punch set. Rotate the crank and examine it for damage before you put the bearing cap back on. There are people that claim you can buy a repair sleeve for the rear, but the only one I was able to find was a repair for the front. I've done several RMS', and the last one I rotated the crank and saw where it had been gouged previously. I used some 2000 grit sandpaper to try and polish it, but it started leaking again in about 4 mos, and its still leaking. As far as I know, the only way to fix this is replace the crank. Unless your MJ is lifted, you may plan on having to drop the front axle to get the pan off. 

 

2) Use FelPro rubber gaskets on the oil pan and the valve cover. The next guy that takes it apart will appreciate it (It might be you).

 

3) As long as I've been working on the 4.0's (have an Xj Waggy I've owned 24 years) I was not aware of the fuel pump ballast problem. It can drive you nuts. If the ballast begins to fail, it is possible for it to continue to send enough fuel to the rail to crank the engine, and show correct initial pressure on a guage, but the fuel pressure (and the engine) will die in short order. It mimics a faulty fuel pump. My 1987 XJ does not have one and I saw no mention of it in the Haynes manual. I replaced the fuel pressure regulator, the MAP sensor and the TPS on this XJ before another member of this group told me to bypass the ballast, which fixed it. Which leads me to another suggestion. There are ways to check sensors, but if you have in your possession sensors you know are good, sometimes its faster just to replace and eliminate. Mark them as good and save them for later use.

 

4) Cheap drive belts can cause squeeks and squeals that will have you going nuts trying to find which pully is the culprit. I found that Gates belts are more expensive but definately worth the price. And as I've seen in some of the previous posts, its a good idea to carry an extra drive belt and idler pulley. Along with a 13mm wrench to loosen the PS pump and install it. In my opinion thats a poor belt tensioning system, but it is what it is.  Its a good idea for you to take some time and see how this thing works while you are at home so that when the thing breaks beside the road you aren't scratching your head. The later XJ style is not great but better.

 

5) From experience from working on other makes I have found that Bosch fuel pumps are superior to the other cheap aftermarket pumps out there. 

 

6) I have found that deleting the coolant flow valve on the 4.0L can eliminate the potential for problems with that item , as well as that convoluted hose mess. The late model XJs do not have one. If you feel its necessary to shut off the heater core, put a manual inline valve on it.

 

7) When you install an aftermarket radio, go to Walmart and get the $15 install kit and follow the instructions and install it correctly instead of just sticking it in there loose and pushing the dash bezel back over the unit. I know this is very common, I have numerous XJs out here where the PO did exactly that. Strangely, MJ owners seem more inclined to remove their aftermarket radios than XJ owners. I have 5 Mjs sitting here and not a single one of them had a radio in it when I bought it. By comparison I have 10 XJs I've acquired and all but 2 have radios in them. MJ guys like their tunes?

 

8) There are some high quality 8mm plug wire sets available. They are about twice as expensive as those cheap sets you buy at the parts store, but once again you get what you pay for. Same with caps and rotors, there are brass ones and aluminum ones. I was working on a OBDII XJ that showed a misfire on #6, turned out to be a failed plug wire on the junk wire set. I also suggest you use the Champion plugs and stay away from the weird split tip plugs, I've seen those fail a lot as well. 

 

9) Invest in a fuel injection noid tester device that will show you if your injectors are firing (MPI).

 

10) If you suspect your injectors need cleaned don't just dump injector cleaner in the gas tank. Go to the parts store and buy a set of new injector O rings, pull the fuel rail off and clean them with a toothbrush and some carb cleaner. It only takes about 15mins to pull the fuel rail off, lightly lube the O rings before you push the rail back in place. There is no way the crap in a bottle can clean them as well, and you will have fresh set of O rings and super clean injectors. Of course if you get a real wild hair this would be a good time to replace them with some injectors suggested on this site for other applications.

 

11) 4.0L Jeep engines do NOT have PVC valves. I've seen numerous examples of people installing a PVC valve in the rear of the valve cover. If the elbow needs replaced there are generic plastic ones and grommets available, you may need to drill the hole out a little to have it properly vent to the intake manifold. The front one goes to the air box, there should not be a breather cap on the front hole (I've seen that several times also).

 

12) If you get stuck out somewhere with a crank/no start situation and suspect the CPS, sometimes if you disconnect the CPS from the harness, crank the engine over, and then reconnect it the engine will fire. Don't shut it off. If this works, you have determined the problem and gotten yourself home (hopefully).

 

13) Can't remember if I saw this when I looked through these suggestions, but once again, at least HALF of the 4.0L's I look at do not have a fan shroud on the primary fan. I see guys completely baffled as to why they can't keep their vehicle from running hot. These things are available for about 30-40 bucks or cheaper, there's no excuse not to have one installed, and there is no way the fan can operate properly without it. 

 

14) On the cooling issue, just for fun, disconnect your heater hoses and blast some water through the heater core and then put the hose nozzle on the other hose and backflush it. If you havent cleaned it in a while you might be shocked at the crap that comes out. If it appears to be stopped up, you can take an air hose and blow some compressed air through it, I've unplugged blockages that way a lot. Make sure you point the hose the other way or you might be wearing the blockage on your face.

 

15) If you suspect a possible cracked head or slightly blown head gasket (you are loosing coolant with no apaprent leak). Pull the oil cap off and see if you see any milky deposit on the bottom of the cap. That will indicate you may be getting some coolant in the oil. 

 

Most of these tips are from experience with XJs over the years, but since the front half of the MJ is same, they should work. Jeep On.

 

 

[MobilJoe1]

One thing I found out (after I crapped my pants in my comanche at 60 miles per hour on the road) that after I installed 33s or bigger tires is add a front cross member strengthening from frame to frame near steering box. This will keep the frame still and secure on the trail while driving. How I know you may ask? I live to tell the tale of other comanche owners who build their comanches and check safe of off the list. My steering box and steering wheel would not move at all, I mean literally won't move with my full force. My tires At this point moved and separated frames just enough to steering linkage binding up and messed up my steering. At 60 miles per hour and this happens right now? Alrighty then! So, please add a cross member frame to frame front end so you don't crap your pants to. I'll add a pic so you know what I mean tomorrow. Thanks. 

[Jlang]

Even if it’s cold and rainy check underneath for signs of rust when your buying. All Is good though still happy with the trade.

[rockincrawler]

Parking Emergency Brake Rachet Repair

 

When removed the Parking Brake Assy and discovered the teeth worn so I removed every other one as shown in photo.  Made the teeth twice the size/depth.  Theirs one original tooth on the left for comparison.  Works great. 

 

 

[rockincrawler]

Safe Sticker removal procedure

 

Also found an easy way to remove that "Sportruck" sticker without damaging the paint.  My pressure washer with a small fan tip removed the sticker and CitruStrip Adhesive Remover with plastic razer blades removed the glue.  Thanks for a great site.  Richard

[Comanchejess]

On 5/23/2012 at 7:30 PM, Live For God said:

#1- Pull Up That carpet! Pull up that carpet! Pull up that carpet!

My floor is rusted through in several places. because somebody didn't check it :thwak:

#2- if when you try to rev up it coughs and sputters and tries to die, check the fuel filter

#3- if you find a Comanche in a junkyard see if you can buy it for parts

#4- cussing doesn't help you fix your Jeep

I should read these. ill check my fuel filter first thing in the morning, even though I'm convinced that's not my issue, it can't hurt to look.

[brawndon]

it is a good idea but with so many engines that fit our mjs wouldnt it be easier to go and get another engine.(unless youw were doing a numbers matching resto)

What would be a great engine swap?

[Pete M]

57 minutes ago, brawndon said:

What would be a great engine swap?

 

all depends on what you want in the end and how much money/effort you're looking to get in to.   we need more info about what you have and what you want.

[brawndon]

 
all depends on what you want in the end and how much money/effort you're looking to get in to.   we need more info about what you have and what you want.

Okay cool, soooo-
I pretty much have a stock 89 mj aside from the lift I have on it. I got 174k miles on it. From what I want... I’m not too sure I just want to have a variety of option. What I do want, don’t know how plausible this is, is to keep it forever hence the engine swap. I have little knowledge but am trying to learn vigorously so I am no longer ignorant. I want to be able to go off road and be able to drive it long distances to national parks. As far as price range I’m up for anything. Don’t plan on dropping lots of money on it since I am a full time student but it will be good to know how much I will be needing in the future so I can start saving. Thanks for your time!

[eaglescout526]

Both AMC 4.0L and 2.5L are pretty reliable engines and will last well into 300k without a rebuild. If it was well maintained. 

[Pete M]

yup, as Eagle said, if the high mileage is what concerns you, MJ engines are known to hit 300k+ if properly cared for.   the problems usually come from abuse, neglect, or the various sensors and other moving parts failing (which can happen to any engine). Having a relaible engine means being proactive.  Don't wait for the radiator and hoses to pop, if it looks nasty, replace it now.  that sort of thing.  I would recommend starting with Cruiser's MJ tips.  They cover all of the weak points we've found in the wiring and such.  should be one of the first links in the link in my signature.  

[brawndon]

yup, as Eagle said, if the high mileage is what concerns you, MJ engines are known to hit 300k+ if properly cared for.   the problems usually come from abuse, neglect, or the various sensors and other moving parts failing (which can happen to any engine). Having a relaible engine means being proactive.  Don't wait for the radiator and hoses to pop, if it looks nasty, replace it now.  that sort of thing.  I would recommend starting with Cruiser's MJ tips.  They cover all of the weak points we've found in the wiring and such.  should be one of the first links in the link in my signature.  

What do you have?

[Pete M]

in mileage?  I've got a 4.0 with over 200k in my wheeler.