1991 MJ build thoughts: 2wd->4wd, lift?

[kastein]

Steering and track bar disconnected...

And it's out!

Longest. Wheelie. Ever.

Where she sits as of last night at around half past midnight:


UCAs in, axle in, shocks half in (heading for home depot for bolts as soon as I finish this post), steering connected but not aligned obviously, track bar connected, springs in, sway bar mostly connected.

To do: last sway bar bushing bolts, connect lower ends of shocks, grind down WJ LCA sleeves and install LCAs, install new brake hardware (did you know that a new caliper comes with new slide bolts, new shim clips, and new copper crush washers, but NOT a new banjo bolt? :banghead, diff fluid change, thread the breather line up into the engine compartment and put a breather filter on it, throw the wheels on and align it!

 

[kastein]

What's this?! A real axle?

And the whole thing...


(ignore the collection of axles)

Just need to give it an alignment now. I was going to do it today but decided it can wait till tomorrow, I've been on my back under the jeep enough in the last 24 hours.

 

[kastein]

Put in a WJ booster, brakes are still marginal as the rears are impossible to bleed, but it stops very nicely once you get past the 3-4" of pedal travel that's just compressing air. The rear brake lines are still a disaster because I'm trying to figure out what to do about my rusty gas tank (lines go behind gas tank...) - can't find a new sender unit anywhere and the frame for my sender is so rusty I'm not going to be able to reuse it.

I'm picking up a 95-down XJ fuel sender assembly this weekend and hopefully modifying it to fit into the MJ tank properly. While I have the tank out, I'll be doing the remainder of the brake lines and possibly swapping in the 29 spline 8.25 I got (thanks to MrSimon!) so I should be able to bleed the brakes properly soon. Found a thread on ComancheClub that describes the brake bleed process on the MJ, it's pretty wacky, you have to bleed the brakes all the way around, open a front bleeder and leave it open, then bleed the rear brakes, then close the bleeder and bleed them all the way around again. You should all buy stock in Prestone, because I am about to pad their earnings significantly buying all that brake fluid.

 

[Comanchedude]

Put in a WJ booster, brakes are still marginal Found a thread on ComancheClub that describes the brake bleed process on the MJ, it's pretty wacky, you have to bleed the brakes all the way around, open a front bleeder and leave it open, then bleed the rear brakes, then close the bleeder and bleed them all the way around again. You should all buy stock in Prestone, because I am about to pad their earnings significantly buying all that brake fluid.

(open a front bleeder and leave it open, then bleed the rear brakes,) uh..that's just stupid advice. I have a MJ and before I changed the brakes it bleed just like any other similar system. IE nothing special. Also long pedal travel could be just the rear breaks need adjusted out, now if you have a WJ booster setup then use a XJ proportion valve and use just one break line to the rear. that's what I have done, also I put a adjustable valve at the rear to fine tune the rear breaks.

 

[kastein]

That's what the fsm says about bleeding the stock system - according to Eagle, who knows his MJ stuff. I have a 91 full-line fsm at home and will double check sometime.

I want to keep the stock valve because the suspension is staying stock height and I frequently go from empty (daily driver) to over a thousand pounds in the back (home depot or junkyard run) and would like to avoid having to adjust the brakes all the time. Fortunately the load sensing valve is nearly rust free, unlike everything else on the truck.

 

[over2land]

I haven't managed to eliminate the valve on any of my trucks yet, but on my 91 the connecting bar is gone, so it looks like it won't be too long in coming.

I had read somewhere about issues with that setup being unsafe. I forget where, but the poster had run a bunch of MJs and basically suggested ditching it if you wanted to have brakes you could count on in a panic situation.

 

[kastein]

This has changed a lot...

I looked at it last week....I wouldn't want to discourage you from looking at it because it is a low price but be prepared, it's pretty crusty underneath and has a ton of gobbed on bondo.

you've got a pm :sunshine:

Well, it sure is crusty. Been DDing it for nearly a year though

It has made it to Pennsylvania and back something like five or six times now, including two trips with an entire XJ drivetrain and tools to install it sitting in the back.

The gobbed on bondo was easily solved too, courtesy of a Mass driver who decided I wasn't going to merge in front of them in a construction zone. Ran over a traffic cone, it ripped all the bondo off the driver side when it popped up from under the tire.

Another dumb question - the only MJ I have to look at is presently driving to New Jersey, and the gas tank hangar bolts are discontinued. Can anyone with an MJ take a quick look at their gas tank hangar bolts and tell me how long the unthreaded portion of the shank is, and whether it's 3/8 UNC thread or not? Trying to figure out if a standard XJ tank hangar bolt can be substituted.

It is *not* 3/8 UNC thread. I believe it was M10xsomething, and the bolts are much shorter and the threads start further up the shank. XJ J-bolts will not work and cannot be made to work.

Stuff I've done:
* removed headliner (I have the backing board in my workshop waiting for me to get around to reupholstering it still)
* bought an absolute ton of parts
* replaced all the brake lines. The only one still OEM is the part to the right front tire that goes behind the engine, I cut that a few inches back from where it started rusting and replaced only the rusty part.
* swapped WJ booster and master cylinder in. The booster has a leaky gasket in it now though, so as soon as I get a new one I'm replacing that again.
* replaced gas tank and fuel sender.
* installed stock steering skid.
* tossed my Bridgestone Dueller APTs and ZJ Canyon rims on it, because I couldn't stand the rims on it and the tires were horrible.
* V8 ZJ tie rod

Stuff I'm doing within a few weeks:
* 8.25 swap, with ZJ discs.
* 4x4 swap (NP231)
* AX15 swap!
* new gaskets and seals all around the engine so it stops leaking oil in quantities that put BP to shame
* new radiator, power steering pump, water pump, spark plugs/rotor/cap while the engine is out
* full R134a conversion on the AC since it doesn't work and I have all the parts to do this, just need to make some adapters to connect the old style evap to the new style lines and accumulator/dryer
* new rear bumper (thanks MoparManiac!) and custom receiver hitch I'm building.
* stock tcase skid (thanks Rob Mayercik!)
* stock gas tank skid (thanks MoparManiac!)
* snowplow
* possibly a d30 aussie locker, if I can find someone to trade one off of.
* RuffStuff cover on the d30
* custom cover I'm making myself for the 8.25 - 3/8" plate bolt ring, 1/4" plate dome, 1/4" webbing for stiffening.
* new rims (16" steelies off a Crown Vic)
* new tires (Firestone Winterforce)
* new tailgate that isn't dented to hell... well... less so. Keeping the really dented up one for junkyard runs.
* new windshield, it needs it badly
* working on a custom overhead console. Basically I'm taking an XJ overhead console, stripping it down, shortening it, using my heatgun to reshape the plastic, reupholstering it, and making a custom rear bracket for it.
* new doors with 97+ mirrors, power locks, power heated mirrors, power windows. They came off the front of a 96 4dr XJ so I have 2 extra up/down switches, not sure what I'm going to do with them but I may use them to eliminate the stupid mirror adjustment switch that normally goes in the center console.
* new fender flares (black instead of painted to match, I like the mid 90s Sport trim level) and grille+light bezels
* maybe one of these years I'll fix the rust in the floors
* maybe one of these years I'll put 2x6 rocker replacements on it, too.

The rear axle, transmission, 4wd, plow, tires, and diff covers are most likely to happen soonest. Waiting on a rockauto order right now.

 

[kastein]

Things didn't turn out how I expected, as usual. I blew up the trans in my 96 XJ on the way to NACFest and ended up ripping what I wanted off it and signing the rest over to the park as a spare parts hulk. The rest rode home in the bed of Johnny's truck...

Since I'm not ready to build the 98 yet (it's getting a 44/8.8, both locked or spooled, 35s, etc) and I somehow found myself with a spare set of 33" ATs hanging around, I lifted the MJ I said I'd never lift... oops. Funny how that happens :eyes: What else was I gonna do with a set of 33" ATs when I was planning on 31s for the MJ, sell em? Crazy talk!

So it got a new motor, a 5 speed swap, a 4wd swap, a 29 spline 8.25, rear ZJ discs, a few inches of lift, new shocks, a d30 aussie, a d30 ruffstuff cover+lubelocker, 33s, a durango box, new WJ booster (previous one was shot), a new starter, a new radiator, a 96 intake manifold, belt tensioner, and PS pump, 97+ mirrors, and a 97+ nose swap all at the same time.

Next up are the rest of the skid plates (TC+gas skids I have, not installed yet), a custom winch+plow mount bumper I'm building for the front, a custom sorta-stock bumper+receiver I'm building for the rear, a headache rack / light bar, a custom OHC, a new windshield, the 8.25 cover I'm still working on, new front fenders, hood, and new paint. It might also get WJ steering/brakes and power locks+windows.

Once I had money. Then my jeeps and house accidentally my whole bank account :laugh2:

Before:

After:

 

[Dundy]

WTF! 4 posts!?

 

[Shorty]

welcome back, noob:shhh:

kinda crazy-- 4 posts, and there's more than that by you in this thread alone.

 

[XJLI]

WTFFFFFFFFFFFFFFFFFFFFFFFFFFFF he exists

 

[rweaver138]

Ken I'm liking the MJ, she's changed quite a bit. Is it still the "Dirty POS?"

 

[kastein]

It's the clean POS now... the new motor I put in it after my death-wobble snapped the passenger side motor mount off the block has a better rear main seal and valve cover gasket than the previous one did. The motor with the broken mount is getting turned into a backup generator for my house after I put some new gaskets and a coat of paint on it, I bought a J609B form factor 3-phase 15kw generator head and will be machining some adapters to mate it to the 4.0L output shaft.

 

[kastein]

Next up are the rest of the skid plates (TC+gas skids I have, not installed yet), a custom winch+plow mount bumper I'm building for the front, a custom sorta-stock bumper+receiver I'm building for the rear, a headache rack / light bar, a custom OHC, a new windshield, the 8.25 cover I'm still working on, new front fenders, hood, and new paint. It might also get WJ steering/brakes and power locks+windows.

things have changed again

6 1.25" heims
2 14bolt caliper brackets
2 frame side LCA mounts
a frame side UCA mount
an axle side UCA mount
2 90 degree shock mounts
a bag of misalignment spacers
a set of SUA leaf perches for a 3.25" or 3.5" axle tube
a pair of panhard mounts
and a pair of 7/8" heims

...showed up today... :eyes:

will supposedly arrive Monday:
44 diff cover
14bolt diff cover
axle side LCA mounts

no cat pics because I don't have a cat yet.


I'm putting a 44 and a 14 bolt under it. If the 14 bolt hangs me up too much (it will) it is getting shaved. Going to wear out my 33s and then some 35s I picked up from MoparManiac, and then... not really sure :dunno: I have a front 60 and a pair of rear 60s sitting around that I haven't really decided what I'm doing with yet.

oh, it's getting a full frame made out of quarter inch box tubing too, because rocktoberfest resulted in a smashed, buckled frame due to too much rust. With what I have left there is little difference between chopping the rusty floor out and rusty frame bits out and patching it, or simply replacing the whole frame and floor at the same time. Everyone says I'm retarded to spend that much time working on a rusty truck and should just get a new one. No, I don't care. I'm doing it anyways. If it comes out like shit you can say I told you so.

hmmmmmmmmmmmmmmmmmmmmmmm

kidding. a friend of mine from my jeep club showed up to BS today on his way home and we were bored. It would be pretty awesome, though.

 

[MT Mike]

Moved to MJ tech per OP's request.

 

[kastein]

Thanks!

I am still collecting parts for the next series of upgrades. I want this thing to last another 20 years before it rusts out that bad again...

 

[twodoorXJ]

sooo whens it going under the knife?

 

[kastein]

no idea. Whenever I have all the parts and the frame is done :laugh2:

based on my previous build schedule and current work schedule, expect sometime in 2015.

Plan:
* finish getting parts (need AX15, SYE, some more front suspension parts, coil towers, maybe some DOM, definitely some square/rect tube)
* finish measuring for frame
* CAD frame
* build beg borrow or steal frame table
* build frame
* move frame outside, attach new suspension, axles, drivetrain
* at this point, put the original truck under the knife, cut the cab off and attach to new frame, add floors, cage?
* paint, wire, install interior, drive and wheel the shit out of it

 

[twodoorXJ]

Looks like youve got your work cut out for you....but considering the world is going to end december 21, 2012, you better get the move on.:roflmao:

 

[kastein]

oh, might put "replace battery" somewhere in that list. The damn thing seems to not hold a charge for more than a few hours.

So I've been parking it on hills for the time being. Hasn't failed yet.