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2006 Ultimate Adventure - 2007 Toyota FJ Cruiser Build - Part 4: Mocking Up The New Suspension

Posted in Ultimate Adventure: 2006 on October 1, 2006 Comment (0)
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Building the official vehicle of Ultimate Adventure is best described as equal parts two-month pleasure trip and 60-day migraine. This year is no different. We've been busting tail logging thousands of miles, and living out of hotels to the point that our credit cards aresmoking and the boss will be cringing at our expense reports, but in the end we should definitely have the baddest FJ Cruiser on the planet. At least until someone pushes the envelope even further than we can in only eight weeks.

Every year we try to mix up our UA project truck with equal doses of old-fashioned reliable parts and new-fangled innovation. This year we won't be reinventing the wheel so much as trying out a basketful of parts that are fresh on the scene. Additionally this won't be a Cheap Truck Challenge entry, so don't complain that no one can afford this build. The fact is that we see trucks running many of the components here on trails every weekend. It's just that we put all these things on a brand-new truck with less than 3,000 miles on it. In the past 45 days we've cut, welded, and spent plenty of time on the phone ordering custom parts to get this ride ready for its weeklong bash out on some vicious trails, and as this goes to print we have but 15 days to get it done. Check back next month for what worked and where we went to play.

1. Last month we showed you the measuring sessions involved in getting our mellow yellow machine redone, and after the major decisions were made we hauled it over to All-Pro Off Road in Hemet, California, where it has lived for at least a month getting transformed. Our first step was removal of parts, and the front independent suspension was at the top of that list. Independent suspension has many advantages, but no one makes IFS parts for the FJ that can survive with 39.5-inch BFGoodrich Krawler tires. Though we would love to help design and build an independent suspension that can survive off road, our limited time frame did not allow for any research and development for this truck.

2. In order to get all the IFS junk--er, parts--off the frame, we enlisted the help of the official welder company of Ultimate Adventure, Hobart. They came to the party with an AirForce 400 plasma cutter. The 400 can slice steel up to 38-inch and can also pierce through plate to make cuts at the center of brackets. With a bit of practice you can wield one of these cutters like a mini light saber and literally carve out metal quickly and cleanly. Although this machine runs best on 220 volts it can be run on 110 volts in case your shop is wired so.

3. In addition to removing the front suspension, the All-Pro fab crew of Mike Schoffstal and Lee Merriam also removed some of the front crossmembers that run under the engine. These will be replaced with fabricated versions that will clear the new solid-axle front suspension. After all the plasma cutting the frame is ground clean so that the new brackets can eventually be added without paint contaminating any welds.

4. After the front suspension and differential were axed, we tore out the stock full-time transfer case and the rear axle. The transfer case was sent to Advance Adapters where an adapter to a four-speed Atlas transfer case was being built. Meanwhile the front and rear axles were sent to Dynatrac to determine what, if any, parts could be applied to our new Pro-Rock Dana 60 axles. While the final parts were being assembled, we borrowed a set of bare housings to begin mock up of the suspension. Luck was with us as the All-Pro solid-axle kit for early model Tacomas was a near perfect fit onto the FJ.

5. When swapping parts into a truck it always pays to see what parts can stay on the truck and still be compatible with the new parts being added, especially with late-model computer-controlled drivetrains. In our discussions with Dynatrac we decided to try and keep all the stock brake components, and if possible see if we can keep the ABS system working. This would allow two results: One, the master cylinder and brakes would be evenly matched, and two, the dash won't light up like a Christmas tree with all the warning lights.

6. When we got to Dynatrac we found that the brake calipers and rotors would not be a problem; some simple machining of the rotor and knuckle and we were moving ahead. However, we did lose the parking brake from the axle and will need to look into one for the transfer case.

7. The wheel-speed sensors were a bit different from anything we had come across before. Toyota has begun using a solid-state wheel-speed sensor that is made up of many small magnets within one large ring seal on the unit-bearing assemblies. Incorporating this into our Pro-Rock 60s would involve a fair bit of innovation we didn't deem necessary, plus removal of the factory units usually results in damaging the seal. After some testing with a friend's FJ we determined that our manual-transmission FJ Cruiser would perform just fine without the wheel-speed sensors.

8. While the axles were away we began the tricky work of suspension design. The plan for the rear was to remove the four-link and Panhard factory suspension, lose the Panhard and install a true four-link with the uppers triangulated to locate the axle laterally. The factory suspension uses the Panhard to locate the axle laterally, but we have found odd handling characteristics in some Panhard suspension, and wanted to try this more common design.

9. While the rear suspension took some time, the front is even more difficult since it must work harmoniously with the steering. To keep the front axle located fore and aft, the solid-axle kit from All-Pro uses three links plus a Panhard bar to locate it laterally. Our goals were to keep the truck as low as possible for a low center of gravity, match the angle and mounting points of the steering drag link and the Panhard bar to eliminate bumpsteer, and keep all the links from hitting the engine and exhaust components. Tune in next month to see the final layout.

10. The four-speed Atlas from Advance Adapters arrived with a custom adapter and stub shaft to mate it to our Toyota six-speed manual transmission. We chose the Atlas for its high- and low-range options for both two- and four-wheel drive, plus the four-speed Atlas will offer us 1:1 highway high-range gears, 2.72:1 sand or mud low range, 3.81:1 trail low range, and a whopping 10.34:1 rockcrawling low low range. In order to shift all these gears we installed a set of three cable shifters that will be routed around the manual trans and into the cab. In order to fit the cable mounts, two of the casting ribs on the transmission needed to be ground away, plus some custom wiring needed to be done in order to hook the stock harness up to the Atlas speed sensor and hi/low/4WD indicators

11. Finally we used a mock-up 39.5-inch BFGoodrich tire-and-wheel combo and flexed the rear suspension to see what was going to interfere with travel and articulation. Then it was time for more work with the plasma cutter and sledgehammer to get body panels out of the way. Check out our lead photo for a glimpse of next month's story.

Sources

Warn
Clackamas, OR 97015
800-543-9276
www.warn.com
Dynatrac
Huntington Beach, CA 92647
714-596-4461
www.dynatrac.com
Eaton
Cleveland, OH 44114
800-328-3850
www.eaton.com
Advance Adapters
Paso Robles, CA 93446
800-350-2223
www.advanceadapters.com
Fab Fours
Pineville, NC 28134
866-385-1905
www.fabfours.com
Tuff Country
West Jordan, UT 84088
800-288-2190
www.tuffcountry.com
Hobart Welders
N/A, AK
800-626-9420
http://www.hobartwelders.com
All-Pro Off-Road
Hemet, CA 92543
951-658-7077
www.allprooffroad.com
Yukon Gear & Axle
Everett, WA 98204
888-905-5044
http://www.ringpinion.com

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