Gorilla's grand touring TJ

[GoldenGorilla]

A build thread for something oxymoronic and a bit different.

What defines a grand tourer? To me, it's a continent crusher. Something that can comfortably cover alot of miles without wearing on the driver or passenger. It's got to be quiet enough for a conversation with the passenger and to pass the time with music. The suspension needs to have a balance between sport and smooth. And it needs to have the power to do it effortlessly. And because this is still a "real" Jeep, it needs to be able to hit the trails at the end of that drive and get me home safely when we've had our fun.

I bought my TJ Rubi new when I was in my 20s. In 2004 my job was stable after the tech bubble burst, but the economy was still weak and there were deals to be had. My Rubicon had dual tops and every factory option available. I used my purchasing wiles to haggle between a couple of dealers with the exact same Jeep to a great price and finance package.

I had defiantly avoided the just empty every pocket mantra of Jeep ownership for 20 years. Inside I'd done a Tuffy overhead radio console for my ham and CB radios. I also installed a 1.75" spring spacer, some hand me down pro comp springs and some shocks for the new length to fit 255/85 R16 33s. A bit later I installed an OR Fab swingout tire and fuel carrier for a trip into the Maze district where I knew I was going to find myself getting light on fuel.

I had done alot of MTB riding and racing back in the 90s and early 2000s when trails tended more technical than flowy and shocks of the day offered 25-65mm of travel. I was pretty good at seeing and picking lines through obstacles. When I got the Jeep, I was able to run some challenging trails with this setup like Blanca Peak, Golden Spike, Holy Cross. But it turned out that wasn't really what I loved doing with the Jeep. Instead venturing into the wild in places like the Maze District, Escalante or some off the beaten track trailheads in the Sagauche, San Juans or Sangres were more my style.

Wheeler Lake around 2005

Not sure where this was, but it was taken on film around 04-06.

In the Sangres on Hermit Rd

 

[GoldenGorilla]

I haven't driven the TJ a ton over the years. Back when I commuted to an office, I'd drive it once a week. I haven't worked out of an office in decade. So at my starting point I have less than 70k on the odometer.

Time caught up with this TJ despite the low miles. The throwout bearing had squeaked and the rear main seal started leaking probably the day after the warranty ended. I could live with that. But a couple years ago I started noticing some other things. The sun/UV had caused some crazing in the bright silver basecoat in a couple spots which affected the clear coat.. When doing a brake pad change I noticed there was oil around the back of the parking brakes. Rear axle seal leak. The rear shocks were dead, bottoming out constantly. The drivers front inner axle seal - also leaking. And worst of all the sprinkler system between my house and the neighbor was getting water on the frame and into the rivnut pockets on the factory skid plate causing some rust. If I didn't do something drastic the degradation was going to be rapid.

I also wanted to address a lack of performance. It hadn't really lost anything, but everything else on the road has gotten much faster. Climbing I-70 into the mountains was becoming ever more nerve wracking as I couldn't hold the speed limit in the fast lane but was going way faster than the semis in the right. There was also the occasional death wobble. It was loud and my wife didn't love taking it places if it wasn't necessary.

 

[GoldenGorilla]

2019

First up detailing. I won't try to write out everything that goes into detailing. If you're interested Pan the Organizer on You Tube is a great intro into techniques, tools and products. I did a deep wash/clean of the paint including a full claybar. I wet sanded some fine foliage induced pinstripes out of the clear. Did a full compound and polish of the gloss paint from stem to stern. Touch up of what I could address. Finally a full ceramic coating primarily for UV protection. It has completely halted the issues with the paint. I'd tried several products over the years and like the NanoBond product pretty well. It lasts better than others I'd tried and it is affordable. While it's hydrophobic quality has waned over the years, I spray a bit of detailer's spray on my vehicles when drying them and that helps keep the water beading up. I probably need to freshen this up. I replaced the bumper milk jugs at this time too. I also treated some of the plastic parts with Adams Polish VRT which helps to bring the black back.

Example of the paint crazing thing some of the metallic paints are seeing. It's a bit in the paint and the clearcoat, but really hard to photograph. I have not seen any new spots since doing the the ceramic coating 6 years ago.

She cleans up

I also installed a Boom Mat in the hard top around this time. I was shocked how much this tamed the echo between floor and ceiling in the Jeep. You could also hear the radio much better with this done. I had a db meter within an app I use on my phone and it showed this cutting 4db from a number in the mid 80s. This was kinda the impetus for the whole grand touring concept.

 

[GoldenGorilla]

2024
Some years passed and those other age things were showing up fast.

The most pressing driveability issue at this point was the shocks. Replacing them improved the ride quality greatly, but I felt it would do alot better with fresh springs. I went with Rancho's 2.5" springs and the RS9000XL shocks, perched on some fresh spring isolators from energy suspension. It sits nice and level with the hard top and rides much nicer. It's sitting at .5" higher than the old setup. I also finally did some adjustable track bars at this point going with JKS and got the axles squared up.

Back Springs. The mystery springs were supposedly 2" lift Procomp, but the person who gave them to me said they'd sagged to ~1"


Front installed


Trackbar with ample anti-seize before installation

 

[GoldenGorilla]

Gears and axles
Next up I turned to the leaking axle seals. I had a local shop quote the rear seals a while back and they said $1k. To install $100 in parts? No thanks. Black Friday brought a sale on some CrMo axles complete with all the parts for well less than half that and my friend has a press. I'd have my stock axles ready when my dad's LJ Rubicon seals start to leak and make the whole rotation alot faster and then I'd have his original axles as a spare for me. When researching the front inner seals I realized I'd have to pull the carrier to replace that seal. I'd never seriously considered having the gears changed for 33s since it was tolerable to me with the 4.10s.
After very carefully looking at the options, I decided my priority was to keep the rpm under 3000 at 75-80mph while lifting the RPMs enough so that I could maintain 50+mph at Eisenhower tunnel in 4th gear. It's not that I think the Jeep can't sustain 3000rpm, but I find it more relaxing to drive this vehicle under 3k.

I ran numbers through GrimmJeeper's calculator.

4.56 ratio at various RPMs

4.10 stock ratio left and 4.56 on the right at key speeds

I studied the factory power chart. The green mark showing about a ~20hp gain at 50mph in 4th gear and the yellow mark aligned to rpm at 75mph in 5th.

I was almost able to hold 50mph at the tunnel, so 20 hp should be meaningful here (26% increase at WOT).

The gear oil from the leaking rear axle dribbles down around the parking brake, so I also decided to replace those pads and rotors while doing this.
Not much to say about this that hasn't been said before. Installing axles is straightforward. Installing gears is a pain, especially when doing it on the garage floor. The studs Ten Factory include with the Rubicon axles are still not long enough for the Moab wheels and you need to press in some longer ones. Setting up the parking brakes is also a bit of a pain in these IMO.

The gears had my speedo off on the slow side of actual now and my passenger tends to disapprove of my preference for traveling slightly above the speed limit anyways. A speedo healer was installed.

I'm making some headway towards that performance issue headed up the interstate. But this exposed a minor annoyance. With 4.10s I had a mild thrumming vibration at 80mph. Kinda told me I was going too fast. With 10% lower gears that now starts at 72mph and we have lots of 75mph roads, so I'd really like to get this sorted. There have been vibration threads out there specifically with the Rubicon since the Rubicon came out in 03 including stock ones, so I'm not sure I'll ever reach a degree of smooth I'd find 100% acceptable. But I'm gonna try.

 

[GoldenGorilla]

First stab at some performance gains
Roller Rockers
The 4.0 valve cover has just enough clearance to use a non-adjustable 1.7 roller rocker from Harland Sharp. Scorpion also has some 1.7s, but they don't seem to clear the stock valve covers. These increase valve lift and with the stock cam's .408/.414 lift this provides another .255"/.029" of added valve lift. This is close to what the Mopar purple performance cam provided back in the day. From what I've found should add 9-12hp at peak without giving anything up. I figured it was a good time to swap the valve cover gasket which can leak at the back. This was a pretty easy level of effort apart from the annoying wiring harness bridge at that back.

Soak the roller rockers in some high zddp break in oil and then torque them down to spec. The hydraulic flat tappet lifters don't require any special valve lash checks.

HP Tuners
I also got an HPTuners MPVI3 at this time and added a bit more advance under wide open throttle (WOT) conditions. I also got rid of the shift suggestion light on the dash and eliminated the speed limiter. While I agree the TJ doesn't need to go any faster than 92mph, the rare occasion where I'd hit that fuel cutoff limiter is abrupt and unwelcome.

Before starting this project I couldn't quite hold 50mph at the last climb to the tunnel. At this point I can hold 65mph in 4th with the gas pedal pinned to the floor.