March 2026 - A Slippery Slope Build

[89 MJ]

March 2026 - The Slippery Slope Project

-And the MJOTM Thread That We All Knew Was Coming-

Owned by @Gjeep

 

Build Thread- 

 

Year/Model – 1991 Pioneer 2WD AW4. (Odd Pioneer build as it was an upper trim level in that year but came from the factory with no AC or radio.)

 

As purchased:

 

Drivetrain- 4.0L upgraded with Borla stainless exhaust/ MagnaFlow catalytic converter; NOS ‘99+ XJ U-style intake manifold & valve cover; Bosch 4-hole injectors; Bored 62mm throttle body; Factory ’95 XJ R134a NOS AC system; All new/ NOS sensors, senders, cooling system, motor mounts & horizontal oil filter adapter; AW4 transmission cooler; Bosch fuel pump.

 

 

Cooling- New heavy-duty factory radiator & NOS Modine heater core. All components NOS to factory spec. Mopar ‘97+ XJ electric fan added when AC installed, complete with dash override switch.

 

Electrical/Ignition- Added-in factory style PDC fuses & relays to keep engine bay appearance clean to run headlight harness, amplifier, subwoofer, and various USB power to cab; Added ignition & 12V terminals to the interior fuse block to run power to plug-n-play interior side; DUI distributor cap & wires with ZJ TSB relocated to passenger inner fender NOS ignition coil; 200amp Mean Green ’99+ XJ connector style alternator.

 

Suspension/Steering- Straight axle up front (upgraded to a ’99 XJ beam to use hubs and newer rotors/ calipers); Dana 35 in the rear with an Eaton locker, 3.55 gearing. NOS ‘97+ steering box & pitman arm; Front suspension 100% replaced to: NOS ZJ V8 sway bar; Moog ZJ steering components, control arms, new ball joints, OME 1.25” coils, KYB MonoMax shocks. Rear suspension: General Spring Metric Ton 3/2 leaf springs, XJ shackle and KYB shocks.

 

 

Interior- ’87 vintage black interior with Mesa fabric factory XJ bucket seats; Column shifted AW4 converted to center console shift, NOS tilt steering column setup; First generation XJ modified overhead console; Factory power windows & door locks (tailgate power actuator/ lock wired); Factory power mirrors; ’95 XJ complete R134 AC system installed; New HVAC related seals sourced from CC member @H3ADBANG4L1F3; NOS ’87 AM/FM radio teamed with RediRad aux (modulated through radio) to Bluetooth setup also hard wired for center console connectivity option; Rockford Punch compact amplifier PBR400X4D running Kicker 5.25” door and 6.5” B-pillar speakers; Pioneer TS-WX010A under the passenger seat compact subwoofer; NOS factory first gen digital clock; DEI alarm/ starter kill; Acoustic matting and insulation all around.

 

 

Brakes- ’95 XJ dual diaphragm brake booster & proportion valve (eliminated load sense at rear); PowerStop cross-drilled rotors, NOS calipers, soft lines; PowerStop rear drum brakes; NOS XJ hand brake.

  

Lighting- Exterior: Holley RetroBright 5700K headlights; IPF headlight harness (re-wired because it didn’t directly work with Holley lights); NOS TJ front bumper & upper cab light bar fog lights, fitted with 5700K bulbs to match headlights; Key parts new taillights with 50W backup bulbs; Hobbs under the hood crank retractable work light. Interior: Added Euramtec B-pillar & factory footwell lights, in addition to overhead console lighting tied into aftermarket mid-‘90’s Ford F150 3^rd brake/ cargo light combo.

 

Exterior- New style seal front windshield; ‘97+ XJ full door glass with ’05 Beijing XJ lower window wipes (allows for use of original lower window metal trim with full length Beijing XJ sourced rubber wipe); Relocated washer bottle via ‘97+ XJ inner fender reservoir; Custom above cab light bar made from 99+ XJ roof rack components, powered by a CJ foot/ floorboard mounted high-beam switch; Relocated jack & crank under the hood using early ‘90’s F150 modified bracketry to keep the MJ cab interior backwall free from clutter; Power tailgate lock/ actuator with cargo light sense trigger for when tailgate is open or closed. ‘Comanche Chief’ graphics; NOS Mopar Jeep drop-in bedliner; Krustyballer MJ hitch.

 

 

Wheel & Tires- BFG All-Terrain 30x9.50R15 tires on American Racing Matte Black Vector rims with custom Jeep logo’d center caps.

 

Misc- Revised vacuum line setup using ‘99+ XJ main tube off intake manifold.

 

Best MJ story- I was looking for a ‘beater’ truck I could use around the property and Home Depot runs, but finding this one-owner MJ was a surprise. I was on vacation with the family in the Bahamas when it popped up for sale in Washington state. I had connected with the owner on Facebook Marketplace that same day asking about the MJ – but I had a full week of vacation in front of me and an 85K near all original MJ up for grabs by first taker available. His original asking price was $12K and he had several who were interested. As the days of vacation continued, I was more and more tortured at this MJ getting away, so I asked the family for forgiveness as I boarded a cobbed together day plus trip back to Washington. I made it. And was able to buy the MJ for $9K after a long Jeep chat with the owner sharing my other MJ/ XJ builds. Success – almost. Pouring rain like I had never seen before and brakes that were a non-factory spec anti-lock. They were atrocious. First hour there was no rain, then the downpour. 7 hours to home and I switch the windshield wipers on… nothing. Dead. I pulled over to check fuses, wiring and called a number of surrounding auto parts stores for an XJ wiper motor. And of course no one had one on hand. And no wrecking yards open on the weekends. Back into the MJ and on the road back home, God willing. Thankfully, I made it.

 

CC is Awesome! Why? 

The CC crew is the reason MJ’s are still on the road – and being built and rebuilt. A resolute and enthusiastic bunch who have motivated the aftermarket to come alive with products specific to our few in production number trucks. And that’s not counting those among the CC members who have taken it upon themselves to produce the long gone, but still in demand parts. Everything from bucket seat brackets, to receiver hitches, to 3D produced seat bezels, cupholders, HVAC seals, etc. Thank you for keeping the products and knowledge of these trucks alive with enthusiasm – Couldn’t do it without you and us all.

 

 

Alright, I'll stop teasing you all and put in some pictures of the full truck:

[fiatslug87]

Congrats! Another beautiful build by Gjeep with attention to detail that’s second to none. 
 

Finally, I was wondering when this would make MJOTM. 

[89 MJ]

1 hour ago, fiatslug87 said:

Congrats! Another beautiful build by Gjeep with attention to detail that’s second to none. 
 

Finally, I was wondering when this would make MJOTM. 

I've been wondering the same! If this is his definition of a beater, I can't wait to see his other one when that is finished!