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Upgrade Priorities for a Stock 1984 Jeep CJ7


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I just recently purchased a 1984 CJ7 Laredo. The Jeep is bone stock, including the 258ci engine, T-5 transmission, Dana 300 transfer case, Dana 30 front axle, AMC 20 rear axle, and hardtop. The previous owner took meticulous care of the rig. After many hours of research and visiting many parts websites, I was hoping for some advice on what upgrades I should install and how I can prioritize these projects. This Jeep will be used around town, on coastal foothill fire roads, and trails around Bear Valley, CA. So far I'd like to do the following items:

 

Twin Stick conversion on TC

2.5 inch suspension lift kit

32" tires (though not sure of axle drive ratios yet)

Full rollcage

AMC 20 retrofit (can't decide between solid axle conversion or full floater kit)

Body re-spray

 

My budget is $5,000 and my DIY skills are intermediate. I already have the Jeep Owners Bible and will be picking up a copy of Jeep CJ Rebuilder's Manual: 1972 to 1986

 

Maybe down the road, I will consider an EFI addition and transmission upgrade/change.

 

Thanks

Peter

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Very nice platform for a Jeep CJ build, pzanger!!!  I like your conservative plans, especially for such a pristine Jeep.  Glad you're keeping the AMC Model 20 rear axle, it's quite durable with the one-piece axle shaft upgrade.  Full-floating is good for a disc brake conversion, short of that the one-piece axle shafts solve the wheel hub shortcoming of the AMC rear axle.

 

You should be well within budget.  The body repaint is obviously a wild card for cost.  I am really pleased with your plans for this vehicle, and the EFI conversion is a major improvement down the road.  Howell's TBI works well, and the Mopar EFI system has become quite spendy—though it offers MPI.  Some retrofit the 4.0L stock EFI systems to the 4.2L.  I'd like to see a company make a conversion wiring harness for retrofitting 1991-up 4.0L EFI to the 4.2L/258.  Many find the wiring an obstacle when cutting up and splicing a stock 4.0L wiring harness to a 4.2L chassis/engine.  An external fuel pump and filtration are also necessary with a PCM governed fuel pump trigger.)  If Mopar would offer the MPI wiring harness as a standalone item, it would be quite popular for adapting the 1991-95 (pre-OBDII 60-pin PCM) EFI/MPI to the 4.2L.  Howell's TBI system is much easier to fit as a "bolt-on" and costs considerably less, too.

 

You'll find my Jeep CJ Rebuilder's Manual 1972-86 (Bentley Publishers) helpful overall.  As for a transmission retrofit, the contemporary solution for stamina and overdrive is the AX15 from Advance Adapters plus the new Advance Adapters bellhousing for the AX15, which will fit your 4.2L engine.  If you want monstrous stamina, consider an NV4500 conversion.

 

Please keep us posted on your Jeep buildup!  Bear Valley is a great base for four-wheeling and backcountry exploring by 4x4 or foot...

 

Moses

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Thanks for the encouragement, Moses. Regarding suspension lift kits. is there anything to look out for? Prices on kits can vary widely, even when accounting for shocks. Any thoughts on roll cages? I was looking at a bolt-on sport cage kit from Hard Rock 4x4 that maintains the factory legroom.

 

PZ

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You nailed the issue on lift kits.  Shocks and springs determine the pricing.  I prefer quality U.S. or Canadian steel leaf springs with gas-charged shocks.  Spring rates vary, so ask about ride quality and make sure you account for the hardtop weight and other add-ons like a front winch.  You may want a stiffer spring design to offset accessories weight. 

 

The roll cage can be a "kit" like spdljohn is doing or a premade cage.  If you do not have welding equipment, the latter could make better sense and costs less in the long run.  Fitment tips and observations are at the "spdljohn" discussion. 

 

For maximum safety, I like a clamshell mount (cushioned for body movement) to the frame.  This ties the body to the frame in the event of a major rollover.  It also complicates the installation and is the main reason why most are content with a cage that simply attaches to the body.  Keep in mind that body mounts must be in top shape to help prevent body separation from the frame during a rollover.  We're talking extremes, and again, most content themselves with the protection of a body or tub cage that does not attach to the frame.

 

Moses

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  • 2 months later...

Two months later, we've finished the lift kit install. Went with an Old Man Emu 2.5" lift with YJ spring conversion, greasable shackles, and Pro-Comp hydraulic shocks. Since diff gearing was 3.31:1, stayed with 31" tires. Went with Cooper Discoverer STT's. Replaced the rear bumperettes with a dual 3" tube bumper with a 2" hitch receiver. Next up will be new front seats. 

 

I do have a question on steering. There is some play in the steering wheel, maybe an inch either way, before the wheels move. How can this sloppiness be reduced? Is the problem in the steering box or is it with the front end components?

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pzanger...Guessing you have power steering, though some CJs of this vintage don't.  Regardless, isolate gear play by placing the front wheels in the straight-ahead position with the steering gear on center.  If necessary to confirm the gear center, lift the front axle off the floor and turn the gear lock-to-lock, then halfway back to center.  Make certain the steering wheel centers up at the same time.  If you are still questioning whether the steering is on center, disconnect the pitman arm joint and gently turn the steering gear lock-to-lock without pressure at the ends, then back halfway to center. 

 

Engine off and under the vehicle, clutch the steering shaft above the steering gear in one hand and the pitman arm with the other.  Rock the steering input shaft back and forth very lightly to confirm how much play exists between the pitman/sector shaft and the gear's worm.  If there is virtually no play over the center position, and the gear moves smoothly lock-to-lock, eliminate the gear as your play source. 

 

If the gear is not worn or loose, look to the tie-rods, pitman ball-studs and their sockets.  A quick check for play is to jack one front wheel safely off the ground, clutch the lifted tire at 3-9 position, and shake the wheel/tire back and forth while someone watches for looseness and play at the steering linkage joints. 

 

Sources of play beyond the gear or steering linkage can be loose wheel bearings or knuckle ball joints.

 

Let us know what you find...We can go from there.

 

Moses

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