A YJ with an LS, 40's, Coilovers, & Spidertrax Axles

[Fouledplugs]

This 1995 YJ was purchased for me when I was 16 as my first vehicle. This build will focus on leafs, a stretch, a LS, and some one ton axles. This build will take a while as I have a job that requires my full attention and focus from time to time, to include traveling outside of the country for multiple months at a time.

It’s nothing special in it's current state, it has a 2.5 liter 4 cylinder that should have never been offered in a Jeep and an AX-5 manual transmission. I don’t recall how many miles it had on it when I was given the Jeep, I do believe it was under 100k, right now as it sits, it has 130k miles on it.

It came with some off brand soft top so a Bestop soft top and frame was swapped in. Once it had the new soft top on it, it really transformed the overall appearance.

I had a job and saved up and purchased a lift for it. I purchased a Rubicon Express 4” lift for it and added 33x12.50/15 SuperSwamper TSL’s.

I wheeled it a lot. Almost every week I would be out wheeling it on trails that were close to the house. My twin brother had a YJ as well with the same exact lift and identical tires. Naturally, we wheeled a lot with one another.

The 2.5 blew a headgasket and I found water in the oil, around that same time, I started my career and moved away from home. The Jeep stayed at my Dad’s house and has been sitting in it’s current state for ~10 years.

2020 rolled around and I am in a position to restore, rebuild, and modify it to what I believe will get me back on some trails more often.

Currently, I have another 1995 YJ that I drive daily and a 2006 TJ that I purchased because it was clean and has extremely low miles; 14k. So I have plenty of Jeeps in the garage and am motivated to get this YJ built and back on the trails.

I have been trying to dig up some pics from earlier years but I am struggling to find any. Here are two I could find.

Build Plans: (continual updates)

• Remaining on leaf springs
• Spring over axle, front and rear
• 12” coilovers with remote reservoirs
• 4 link rear
• 3 link front w/ a steering box
• 40x13.50/17 Nitto Trail Grapplers
• 17 inch forged aluminum wheels to fit 14” rotors.
• 2003 Silverado SS GM “LS” LQ9 6.0L
• Maximum Transmissions built 4L80E
• Advanced Adapters Atlas II transfer case (4.3)
• Modified sport cage
• Aluminum flat dash
• Savvy sliders (researching)
• Savvy aluminum front bumper
• Baja Designs LP9 Pro LED front fogs
• Baja Designs S2 Pro flush B/U lights
• Savvy LED tail lights
• Howe hydro assist steering
• Genright’s, “Growler,” alum stretch (7”) tank & alum skid (GST-4005/Discontinued)
• Dynatrac HP ProRock 60 front axle, driverside drop, kingpin, full width, 14 inch Spidertrax disc brakes w/ Wilwood forged calipers
• Spidertrax chromoly 3.5 inch front axle housing, 4130 chromoly skid plates, full width, Spidertrax steering inner and outer knuckles, 14 inch Spidertrax disc brakes w/ Wilwood calipers, Reid super kingpin Dana 70 forged inner knuckles (C’s), Reid super kingpin steering knuckles w/ aluminum high steer arms, double shear steering, 05+ Ford SuperDuty unit bearings, Ford SD OEM brake calipers, Ford SD OEM rotors
• Spidertrax chromoly 3.5 inch rear axle, 4130 chromoly skid plates, full float, full width, Spidertrax 8 lug unit bearings, 14 inch Spidertrax disc brakes w/ Wilwood calipers
• GearWorks big bearing HP 10 inch third members w/ 35 spline ARB air lockers and chromoly third member skid plates
• Howe 511 steering box w/ ram assist

 

[Fouledplugs]

Near the beginning of 2020 as soon as it warmed up, I
made a weekend trip down to Alabama and upgraded the 2.5 liter.
Reminder: this YJ has been sitting for about 10 years out in the elements. So it’s gonna need some major cleaning up.

The absolute best upgrade you can make to a 4 cylinder Wrangler, is to remove it.

 

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The 2.5, AX-5, NP231, and exhaust has been removed.

Moving forward I knew I wanted an LS and I did not want a 5.3. I wanted a 6.0L.

After removing the factory YJ engine, I started checking eBay for pullouts. I happened upon a very clean Texas Silverado SS LQ9 6.0L, which is a high output LS truck engine that can be found in the the Chevy Silverado SS and the Cadillac Escalades.

The pullout had the orginal full harness and computer to include the DBW gas pedal. The engine had a trans attached but it was a 4L65E, and I had already made the decision that I was going bigger, I was on the hunt for the bulletproof 4L80E.

I negotiated a price for the engine, harness, and computer but without the trans. I purchased it and had it shipped to my door.
Delivered:

 

[Fouledplugs]

Soon after the engine was delivered I drove back to South Carolina and have been staying home since this Covid-19 crisis started. So working on the YJ has been put on hold. But I could still buy and pile up parts for the build...

I shopped around for a used 4L80E and figured if I bought a used trans, at a minimum I would have to have it gone through to check it’s “health.” I concluded that it may be more beneficial to buy one that is built from a reputable trans builder/shop.

I settled on Maximum Transmission out of California and purchased a built 4L80E.

I am still waiting on it to be built and shipped to my door. Should take about 5-6 weeks.
Maximum Transmissions

 

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I have always been drawn to the Ford 9 inch for a choice rearend in a Jeep for rock crawling. They can be built super strong and parts are everywhere for them, not to mention how much there is as far as aftermarket support goes. They have proven their strength in the drag racing world.

I also will be stretching the rear end as far back as possible, yet still retain the gas tank under the tub using a GenRight stretch tank.
A Ford 9 type housing gives me the most stretch possible as the measurement from axle centerline to the rear most portion of the differential housing is the shortest of any one ton, even the RockJock 60’s and 70’s.

I purchased a complete full width Ford 9 years ago from a pull it yourself and never did anything with it because of moving away. My intentions, even 10 years ago, was to build this Jeep into a one ton crawler one day.

I decided to ditch the junkyard Ford 9 that I have sitting in the garage and decided to build a much stronger rear axle setup. I wanted a ring and pinion to match a one ton front end. So I started looking at fabricated 9 inch housings that I could run a 10 inch ring gear in. A dana 60 one ton uses a 9.75 inch ring gear. The Super 60, found in 05 Ford Super duty, uses a 10 inch ring gear. The super 60 was actually designed off the highly desirable 78-79 Ford High Pinion axle.

I have no intention on ever selling this YJ, so going with an expensive, yet bulletproof rear axle to fit the LS engine was an easy choice . I highly doubt I will ever need to look for another rear axle from here on out.

I put in a custom order in with Spidertrax for a full width full floating axle. I chose their Pro Series 3.5 inch housing which uses 4130 chromoly heat treated 3.5 x 1/4 inch wall axle tubes and their full float housing ends. The housing ends utilize a unit bearing instead of a spindle and has been proven in the Ultra4 world. Not to mention unit bearings are dead simple when it comes to maintenance, rebuilding, and repair

3-1/2" OD Pro Series Housing​

www.spidertrax.com

I had Spidertrax weld the full float ends on, weld in the outboard seal seats, weld in a fill bung and cap, and finally the lower diff housing skids. Everything showed up a few days ago fully tig welded and it looks like a piece of artwork.

 

[Fouledplugs]

The only thing I would do different with the Spidertrax axle order is change the location of the fill cap. I would have moved it up and to upper right portion of the center section.

Or had a flush type cap welded in it’s current location often seen in the trophy truck world.

I will address that issue later, I’m thinking some type of skid may need to be fabricated to keep the rocks from damaging it.

The goal is to gain as much stretch as possible in the rear while still maintaining a gas tank under the tub. If I was going with a fuel cell in the tub I woulda have gone as much cheaper route; a GM 14 bolt, cheap and strong.

I could of had a built 40 spline 14 Bolt or two from Crane Axle for half the cost.

 

[TWiG01]

This thing is going to be a monster! I love the red and blue of the YJs. Two classic colors

 

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The Spidertrax chromoly full float 35 spline 8 lug unit bearings were delivered.

Spidertrax builds beautiful parts. I still can’t get over how well their workmanship and craftsmanship is and their prices reflect it. I shouldn't have any issues with these unit bearings for quite some time and if I do, they are completely rebuildable.

Just like the chromoly housing, the unit bearings are built in house at Spidertrax and made 100% in the USA.

Did a little mocking up to see them on the housing.

 

[Fouledplugs]

This thing is going to be a monster! I love the red and blue of the YJs. Two classic colors

Thanks, this YJ will stay on leafs so it won't be built near the amazing level of some of the builds here. This Jeep means a lot to me and I always wanted an old school Jeep built for mild crawling on leafs.

 

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A delivery from Spidertrax always makes me smile. Brakes are here.

Spidertrax Billet Alum 8 Lug Brake Hats
Spidertrax Rotors
Spidertrax Double Sheer Caliper Mounts
Wilwood Forged Dynalite 4 Piston Calipers

 

[TWiG01]

Thanks, this YJ will stay on leafs so it won't be built near the amazing level of some of the builds here. This Jeep means a lot to me and I always wanted an old school Jeep built for mild crawling on leafs.

Even with quality leaves, you should still get some great flex out of it.

 

[Fouledplugs]

Unit bearings, brake hat, rotors mocked.

Spidertrax 6.5 inch billet aluminum brake hat and the Spidertrax 14 inch solid rotor mocked up.

14" Ultimate Rotor (For 6-1/2" BC Hat)​

www.spidertrax.com

8 Lug Hat​

www.spidertrax.com

 

[Fouledplugs]

Even with quality leaves, you should still get some great flex out of it.

I hope so, I'm willing to throw a bunch of different springs at it and see.

 

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I was shocked at how light weight the forged Wilwood Dynalite calipers are.

 

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Detailed Spidertrax rear brake mock up.

• 14 inch Spidertrax solid rotors
• 6.5” billet aluminum rotor hats drilled for Spidertrax 8 lug unit bearings
• Spidertrax double sheer 5.45” lug caliper mounts
• Wilwood forged 4 piston dynalite calipers (Wilwood 120-6818)

Spidertrax 6.5” brake hats that accept their 14 inch rotors. Each Spidertrax rotor hat weighs in just a hair over 1lb.

The billet hats are drilled for the Spidertrax 6 and 8 lug unit bearings. I am confident they would fit any one ton unit bearing that is built with 6 or 8 on 6.5 inch lug patterns. Which are popular Ultra 4, trophy truck, and desert pre-runner lug patterns. 6 on 6.5” being uber popular these days for most race teams.

The Spidertrax rotors are 14” in diameter and measure 3/8” thick. Having a 14” diameter rotor will require me to run a 17” wheel to make everything fit. It isn't a problem, IMO, a big tire with a 17” rim looks more proportionate than say, a 33” tire on a 17” rim.

Assembly of the rotors and hats requires a long hex bit socket or a long hex key. I was unable to use my standard short hex socket, as the diameter of the 3/8” drive socket interferes with the relief that is machined on the hat for hardware access. I am using Snap-on 3/8” drive sockets, other brands may not cause issue...

Fully assembled hat and rotor for mock up.

 

[Fouledplugs]

Left rear, right rear rotors with hats mocked up and on the Spidertrax unit bearings. It provides a very clean look.

I will get parts on scales later. I am curious as to the overall weight of a Spidertrax axle in comparison to a junkyard Dana 60, Dana/Spicer crate 60, and a Rockjock 60.

 

[TWiG01]

I hope so, I'm willing to throw a bunch of different springs at it and see.

I know Deaver leaf springs are well respected (or at least used to be)

 

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Anyone point me in the direction of a nice industrial scale that won't break the bank I can play around with in the garage?

 

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I know Deaver leaf springs are well respected (or at least used to be)

Still are, Scott Born (Deaver Spring) was on a podcast that I listened to last week and was talking leafs. He stated it's really tough when trying to build the appropriate spring for something that's highly modified and using different springs from all kinds of vehicles.

I'm leaning towards XJ springs and front Waggy springs with the offset center pins. But time will tell once I get to the point of mocking it all up and seeing what fits best.

 

[Fouledplugs]

Completed mocked up bare housing minus the calipers and caliper mounts.

Waiting on a shop out in California to release their 9/16” machined zinc coated lug nuts. If ARP carries some, Ill prob just go with them if they meet the wheel specs. Once I have lug nuts, the caliper mounts can be welded up for double sheer and bolted on.