The H3 Build

I've since sold the Montero and miss it and getting back to overlanding I realized there were some lessons learned with that platform, and while I looked in ernest to find another Gen III, or even a clean 2.5, there's that law about nostalgia that says you can never go back. I'm also now without a garage, limiting my own wrenching and rattle-canning, and someone boosted my entire Craftsman mechanics set reducing me to scratch. In junior high I think we called this a do-over.

I thought I'd go the Jeep route: incredible aftermarket, proven platform, and huge user support systems. But, as we say in this area, you can't swing a gray-hair around without hitting one, the ubiquitous general purpose vehicle. Ditto the FJ. So I turned to the Hummer H3. I've secretly wanted one since they came out in 2005 and with its limited run and termination in 2010, the market hasn't quite figured out what to do with it.

I've made fun of Hummers since the H2 hit the market, and when the H3 came along I blew it off as GM's incarnation of Hummer culture on a Colorado platform. As I dug in and did the research I found out that wasn't such a bad thing. The biggest complaint is it's standard powerplant, an inline five that feels more Massey-Ferguson than GM Vortec. But even with one less cylinder it produces 242 hp and 242 lbf·ft versus Mitsubishi's 3.5 at 217 hp and 220 PS.

And while the Montero gave drivers and passengers an unparalleled view of the planet, the little Hummer feels like a deuced coupe, though an FJ is even harder to see out of. I wonder if the H3's driving position wouldn't feel so low had I not been conditioned by the excellent ergonomics and position of the Montero. However, the H3 holds it's own in performance and ability in all the ways I want to use it.

Last weekend I came across a 2007 base model in my favorite color, slate blue metallic, and I drove it home.

Planning it's purpose-build for a 3 trail-rating indigenous to our area, I'm looking to start with these modifications:

Replace its 265/75/R16s with 285/75R16s - Done
Mount a Garvin Wilderness Sport roof rack with recovery gear - Done
Add an ARB Awning - Done
Engineer a separate electrical auxiliary circuit system - Done
Upgrade the power-train control module - Done
Add an N-Fab Pre-Runner grille guard and light bar - Done
Add supplemental lighting front and rear - Front done
Upgrade suspension and level - Done

Observations

The H3 has a solid axle rear end on leaf springs with an independent front SLA torsion bar system up front where the Montero as independent suspension on all four corners. I crossed up the H3 on a ravine where I've done the same with the Montero, both in stock form. The extended suspension members of the H3 kept their wheels out of contact with the surface where the Montero kept all four planted.

Habit being what it is, I keep trying to flick the auto stick in the H3 to the tiptronic mode of the Montero, something I'll miss the most from Mitsubishi especially on the hills. Downshifting the H3's automatic is standard GM fare, clunky due to its locking and release to go from drive to third gear, and then selecting drive again runs the risk on an inadvertent free-wheeling neutral. There is a five speed manual for the H3, much preferred for off-road, but I opted for the automatic for better towing. Compromise. The Montero didn't have to.

Ergonomically, these two are from different planets. The Gen III Montero groups instruments and controls into clusters with a simulated wood surround. The H3 is more business-class in materials that look and feel on the cheaper side, but the layout and design is intuitive and accessible, easier to clean, manipulate and read - in the daytime. A bane of H3 electronics is the hardwired illumination behind the controls that requires a $450 pod replacement versus a .79 cent lamp replacement. The temperature and airflow controls on my H3 have no illumination. Good thing they're intuitive. Perhaps an alternative is an adjustable arm mounted led to shed light on the controls a la old aviation instruments. I might be onto something there.

The Montero seats turned me against leather. They're beautiful and comfy, speaking to suburban luxury rather than trail utility. The H3's base trim was a big attraction for me, textile seats with breathable, durable insert surfaces, well bolstered and supported. I'd appreciate another three quarter's inch in height, though.

The payoff in the H3's interior is in the simplicity of the rear seat compared to the center seat of the Monty. The need to access a seldom used third row in the Montero lead to an overcomplicated execution of a seat mechanism that fails in function and form. And when it fails it becomes almost impossible to work around. The H3 is without the necessity of complication allowing the rear seat to fold, stow and restore easily with welcomed access for removal. BUT, the suckers won't fold flat, making my Golden Retriever dance around like a skateless junior hockey coach.

My last ergonomic issue with the H3 is the placement of the power accessory switches on the driver's door, they're too far back. I don't know what considerations had to be made in the design of the door, but I can't imagine what is in the way fore of the arm rest that required its position so far aft.

As it is, in order to hit the driver's window switch, the elbow and shoulder have to lift back and up to get the hand in position, even more awkward for the rear-window controls.

Tires and Grill Blackout - February 9, 2014
I've knocked off the top item on the modification plan; replace the 265/75/R16s with 285/75R16s. I went with Hankook DynaPro ATM RF10s to take care of both on and off road duties.

I also blacked out the chrome grille - too much shiny for my tastes in an adventure vehicle.

This H3 came with Pioneer's AppRadio but had no reasonable place to install an iPhone mount. ProClip makes a clever two-piece mount that attaches to the top and bottom of the plastic surround on the center ventilation pod. It puts the iPhone high for a quick glance and secures it well with easy removal. I wish Pioneer's AppRadio were engineered this well.

Garvin Wilderness Sport Roof Rack - February 15, 2014
I considered two roof racks, a Gobi Stealth and the Garvin Sport roof rack, the latter being a third the the cost. While the Stealth would offer storage the length of the H3's greenhouse with a different construction, I'd be using a rack to stow recovery items and serve as a mount for an awning. While one of the laws of overlanding is the stuff you carry expands by 1.5 times to the available space, I won't be using the square footage of the Stealth and want to resist overloading the top of the rig.

That's why I went with the Garvin.

I researched to to no avail find how it mounts to an H3's existing rack system, so I thought I'd provide that illustration here.

The front of the H3's rails have a plastic cap that clips into place, finishing the line of the rail to the front of the cab. This has a tab that when compressed and lifted, the plastic insert can be removed to access the rail.

With this removed the cleats to which the feet of the Garvin rack mount to can be inserted and positioned along the track.

The rail's channel depth makes it awkward to reach the cleats with the mounting bolts. I found that if I used one bolt without the washers to thread into and pull the cleat up into position, I could easily thread the opposite bolt with washers in place, and then replace the assisting bolt with its washers and complete the mount.

I left all of the hardware hand tightened on the feet to allow easier positioning and centering of the rack once all the feet were mounted into the rail.

The rack ships with the box in four pieces, front and rear ends and sides that need to be assembled, along with six rails that mount longitudinally.

The front of the rack is tapered and the upright stanchions are welded at diagonals to eliminate excessive wind noise cause by parallel supports.

I like the flexibility of configuring the rack to meet the needs of stowing recovery gear like a shovel, a Hi-Lift jack, TREDS, and Roto-Paxs. The channel created by the twin cross-members creates a solid mount for Grip Fists that I'll be using to stow the shovel and jack.

N-Fab Pre-Runner Grille Guard - February 22, 2014
Another lesson gleaned from adventuring in the Montero was worrying about its front-end vulnerability; there was little protection for the radiator and oil cooler. The H3 is definitely more robust, but the frame terminates at the shackles leaving everything above them at a bit of a risk.

The N-Fab guard has a stinger-like design to part away through brush and debris and it has tabs to mount auxiliary lighting upon which are mounted a pair of Hella 700ff lamps. I bounced back and forth between this design and the more conventional brush guard that integrates better into the H3's facia, but given our off-road history the N-Fab hardware will serve us better.

The guard mounts using the stock hardware that attaches the shackles to the frame. This will also serve as a foundation for a fabricated winch mount.

Rear Door Utility Shelf Mod - March 8, 2014
One of our favorite interior modifications on the Montero was the addition of a utility shelf that provided a place for food rep. The H3's rear door stows the jack and hardware assembly behind a removable plastic panel, a perfect place to adapt a shelf to the rear door access cover versus adding one like what was done on the Montero.

Looking at clearances and how the panel is engineered to fit into the plastic surround I decided to use one-quarter inch oak veneer for the shelf and thought to hinge the panel to the surround.

I used a band saw to rough cut the outline of the oak shelf insert going back and forth to the door to test fit, rasp and sand until I was satisfied with the fit and clearance.

Once I had it fitted I stained it with MinWax Cherry stain, three coats, and after proper drying time shot it with Cabot's marine grade gloss spar varnish, five coats. It's far from perfect in finish and craft but it will do the job.

Next, I hung the panel to the surround using stainless steel marine hinges, the best alternative I could find that weathered well, looked better than hardware store fare, and adapted to the flare of the plastic surround. I used stainless 1/2 inch 10-24 hardware with locknuts. I then mounted the oak insert into the opening where it rest and closed the plastic panel over it and locked it down. I used some foam between the oak panel and the jack hardware to give the panel some resistance.

I drilled some pilot holes through the plastic panel for the top two fasteners, and then once it was installed drilled through those holes into the oak panel for alignment. I used stainless flathead one-inch 10-24 hardware with finishing washers on the oak side, with lock washers and thin nuts on the panel side finishing that with black plastic covers. With the two top fasteners installed, I measured, drilled and completed the bottom fasteners.

I wanted a simple way to suspend the assembly and level it out within reason of the H3's cant when parked. I decided to use black paracord that attached at d-rings that were riveted to the top of the panel and to the top of the opening.

In order for the panel to fold flush against its jamb, the paracord would have to detach, so I used a pair of small Nite-Ize s-clips for ease of attaching and detaching. They clip into a bowline knot at the end of the paracord, and to the d-ring.

The top is tied to the riveted d-ring just below the opening using a cow hitch that is tied off down the cord allowing an easily adjustable suspension of the shelf.

The result is a light but sturdy utility shelf that integrates well into the stock panel. Use in the field...

March 11, 2014
Warner Valley

July 10, 2014 - Blue Sea ST Blade Fuse Block
The H3 got a Blue Sea fuse block added to provide six extra circuits for powered accessories such as the Hella 700ff lamps, a CB, and rear work lamps.

Blue Sea Systems make a variety of marine and automotive application 12v fuse blocks. The ST Blade box comes in 6 and 12 circuits with or without a negative bus. I won't be adding many accessories so I opted for the six circuit ST Blade with the negative bus to make grounding something I won't have to troubleshoot.

The ST Blade is mounted to the top of H3's battery box cover between the battery posts. It's powered from the positive post with a 6AWG wire that terminates to a Scorpion 100A breaker with a jump cable made from the same wire to the fuse block. The breaker was mounted in the recess next to the battery box vent to allow clearance for the fuse box cover below to be removed.

A 6 AWG Duralast battery cable grounds the ST Blade to the H3's chassis.

The Hella 700ff lamps need a power supply for the relay (red) along with power for the switch (green). The relay is fused at 15A to handle the 55 watts of the lamps and the switch at 2A. The two grounds (black) are from the lamps on the left and the switch on the right. The relay (not pictured) has its own ground.

This will simplify the addition of other accessories and keep wires tidy under the hood.

The switch for the Hellas was mounted on the small recessed panel behind the gear selector on the console.

Recovery - Hi-Lift Jack and Shovel Mount

Switching to the H3 from a Gen III Montero has been a considerable exercise in scaling down as far as storage goes. The H3 has 25 cubic feet where the Montero had over 43 cubic feet that included an under-floor cubby that was ideal for recovery gear.

I added a Garvin Sport roof rack to provide a place to mount a Hi-Lift jack and a shovel along with a pair of traction devices and a low profile weather-proof box to stow straps, a Lift-Mate and other recovery gear.

The jack and shovel have been mounted using Quick Fist clamps. The jack mount uses the same concept found on the Montero with a 3/8 bolt that protrudes through the steel bar and a stainless steel wing nut to secure it.

I've since mounted a Plano 42" weather-proof locking tactical case that holds a Lift-Mate, a snatch strap, tools and other recovery items. The case is bolted to the rack. I've really come to appreciate the Garvin rack's ability to adapt to load needs with its adjustable cross-members. Along side is a pair of TREDs that are locked to the rack with a 6' cable lock by Master Lock.

PCM Reprogram - July 19, 2014

Even though the H3's I5 produces a bit more power than the Montero's V6, it's sluggish at best with low RPM shifts with flat torque curves. I researched a number of mechanical mods to improve this (within my budget) and found that the most common - air intake upgrades, headers - yielded little change in performance and better fuel efficiency.

From various H3 user forums I heard about PCM of North Carolina and researched their service; they flash and reprogram the factory PCM (power-train control module) promising better throttle response and fuel efficiency, better shift points making better use of the torque curve, and more horsepower.

Sounds too good to be true, but having lived in North Carolina, it's been my experience to have never been disappointed with anything that comes from that state. So I made the order.

I opted for their loaner program where they send a unit to replace the factory PCM while it's sent back to NC for the tune. While their instructions are pretty specific on how to remove the PCM, GM's design of its plug interfaces isn't all that intuitive, so what follows is a bit more detail on its removal:

The PCM is located on the engine firewall on the passenger side behind the coolant and window washer reservoirs.

Looking from above the PCM's cooling ribs you can see the three plugs that connect to it. To disconnect the plugs, remove the red strap on each by pulling it up. It will detach fairly easily.

From a side angle of the PCM you can see the grey ribbed band that surrounds the plug. This band acts like a lever. With some coaxing, lift it up and over the plug.

The plug is engineered so that this lever mechanism unlocks a series of cleats that lock the plug into the PCM. Dust and dirt in the mechanism will make this difficult risking breaking the plastic lever, so it's not a bad idea to blow it out with compressed air. Once the level is lifted all the way up, two red tabs appear at the top if the plug indicating that the cleats are clear and the plug can be removed.

If these red tabs are not in the position shown above, the grey lever hasn't been completely deployed.

With the plug removed, the cleats can be seen.

The PCM is held in place by a bracket. It has two tabs on top that hold it place.

If during the removal of the plugs the PCM becomes free of the bracket like this,

...the plugs will not have the necessary resistance from the PCM module to be removed, so make sure the module stays locked in while removing the plugs.

If the tuned PCM is anything like the loaner, the reprogram is very significant.

July 25, 2014

I've received and installed the upgraded PCM from PCM of NC and I have to say that the H3 has awakened. All that was promised has been delivered and then some - more torque and pull off the line and up the slope, remarkably better throttle response, better shift points on acceleration both on and off road, better use of low range exploiting the I5's torque. I've yet to get enough data on fuel efficiency, but I have to say for the price, the result is well worth it.

I'm baffled why the I5 H3 didn't leave the factory this way. Would have saved GM considerable grief in mediocre performance evaluations, perhaps even the demise of the marque.

Safety

Having come close to rolling the Montero in a river and realizing that with its electric window lifts I'd be in deeper trouble if I or anyone else needed to exit the vehicle, I installed a glass hammer in the H3 in the event we'd ever have to evacuate it through its smaller windows. This fit nicely out of the way on the B pillar. The black bracket has a dayglow button on the left to help locate the hammer.

First Pack - August 1, 2014

I mentioned earlier about dealing with almost half the amount of cargo space in the H3 compared to the Montero. This is both good and bad.

Good from a stand point of lightening your load. This image below is from our Grand Staircase trek:

And while all this made for a comfortable camp set-up, it all added up to diminishing the Montero's dexterity. And, man, that's a lot of stuff.

By contrast, here's the loaded cargo area of the H3:

We've pared down the gear and made better use of the roof rack and a Trasharoo.

As all recovery gear is up top in a weather poof tactical case.

And the Trasharoo holds sleeping bags and pads and the tent.

Accessible and tidy.

ARB Awning and Cobra CB Installation - November 12, 2014

Two important tools on the Montero build are now on the H3, a CB and an awning.

CB - The H3 doesn't have DIN room for an additional component like a CB radio, so I went with a device that has a head unit that mounts under the dash with a compact remote handset that has all the controls. Cobra makes a four-watt CB with a channel scanner and noise reducer, two features I wanted since my last Cobra CB in the Montero. I mounted the small head unit just under the steering column on the firewall, the easiest spot for the install while allowing adequate distance to the handset and accessibility for the antenna connection.

The handset is mounted on the ProClip mount I initially installed for an iPhone. I've relocated the iPhone to the over side of the panel with NiteIze Steelie mount.

Eighteen feet of coaxial cable with Pl-259 Connectors connect the head to the 4' Firestick tunable antenna mounted behind the spare on the rear of the H3.

ARB 4' Awning - I had an Australian 60" Eezi Awn awning on the Montero that converted me to the idea, but not to the convenience since the Eezi Awn's cam system in the legs was unstable at best in calm conditions. This ARB awning solves that and other issues.

Its engineering makes it easy to deploy by one person. The construction is top notch with reinforced corners on the awning and clever plastic disk stays on the struts and legs that keep all the hardware in place until it's deployed. Stowing is a cinch in its PVC reinforced nylon bag with two d-ring velcro straps and heavy duty weather-proof zippers.

Front Suspension Upgrade and Leveling - November 22, 2014

From what I can tell by records and wear, the H3 had the OEM shocks at 125k miles. Its handling is lethargic and reminiscent of an old Buick Electra in its floating feel, characteristics no one wants in an adventure vehicle.

After researching applications and reviews I decided to replace the front shocks with a pair of Bilstein 5100 Series shock absorbers. The installation is straight forward though one might think it necessary to access the shock tops through the engine bay - it's not. It's all accessible within the wheel well.

After the install I adjusted the torsion bars on both sides while the vehicle was still on jack stands and before I remounted the wheels. The bars terminate just behind the B-pillars where the adjustment points can be found.

I tightened these 27mm bolts two and on half turns, increasing the tension on the torsion bars, and combined with the Bilsteins, lifted the front end, reaching more of a level stance. This adjustment resulted in a 22-inch distance between the wheel center and the bottom of the fender, compare to the rear distance of 23 inches.

I modified the Montero with Old Man Emu suspension components and was amazed by the difference in handling and performance. I can say the same for the Bilsteins and the leveling - improved turn-in, firmer suspension, better feedback, less diving, remarkably more responsive. Having been an OME convert, I felt I may be cutting corners with the Bilsteins, but so far, both on and off-road, I'm very satisfied. Time will tell on their durability.

SeatBackPack - November 26, 2014

The H3's front seats have a small cargo stowage system on the back of each that serve little practical purpose and when packed just a smidgeon beyond their capacity, detach from the seat back and spill the contents in the rear footwell. It's the worst designed feature of the H3's interior.

I keep a bug-out-bag in the cargo area where it bounces around a bit when it's not restrained and takes up some of what little precious room is back there (the second worst designed feature).

Using a heavy duty snap fastener kit I designed a T-shape pattern that attaches the BOB to the seat back while allowing the padded pack straps to tuck between the pack and the seat back.

This H3 rarely has rear-seat passengers, but when it does the pack unsnaps easily from its mount and can be stowed in the back.

Dog Deck - February 6, 2015

Our dogs spend more time than any backseat passengers in the H3, as they did when we had the Montero. I did a rear-seat mod on it to make dog travel easier on all of us.

Having made a great improvement in traveling with the Goldens, as well as increasing storage capacity, I decided to do the same on the H3.

Rear-seat removal is straight forward, remove the bottoms from their easily accessible mounts, and then the backs. The 60/40 seat back is mounted on a sub-frame that keeps the backs aligned and rigid. With everything out, this is what's left.

I removed the seat-backs from the sub-frame and reinstalled it. There are two spring loaded doors integrated into the transition that kept debris from falling in between the seats and the cargo area. I though these might be nice to maintain an access to the underside of the platform.

I then made stanchions out of off-the-shelf fencing hardware from Lowe's, four of which were shaped to measure from the floor to just above the six-gallon water tanks that I'll be stowing beneath the deck.

Once I hammered them into the shape and length needed, I fastened them to the floor using the H3 hardware that held the seat-bottoms in place. I also determined to rotate the front stanchions 90 degrees to decrease forward flexing of the brace.

I dog-eared a 2'X4' piece of 3/4 plywood and did a test fit once I had the rear set of stanchions installed.

With everything lined up, I marked the mounting holes on the plywood and drilled them out.

I rounded the opposite edges on the deck and then covered it in gray interior carpeting, using Gorilla glue and a staple gun. I then installed the deck, bolting it onto the stanchions.