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To 4x4 or Not to 4x4
I was wondering what the advantages and disadvantages of having four-wheel drive are for off-road racing and prerunning compared with a two-wheel-drive truck. I have a five-speed 4x4 Toyota Tacoma and am quickly finding the limits of my front suspension. I realize that if I wanted to get long-travel suspension, I would have to rebuild the front axles. Even with custom axles, though, wouldn't you still be able to get more travel with two-wheel drive? I also know that you can remove the components from the front suspension to convert a 4x4 into a 4x2, but would it be easier and cheaper to do that than sell my 4x4 and buy something similar with two-wheel drive? Also, what are the advantages and disadvantages of manual transmissions versus automatics?
- David Hasset, San Diego
The debate rages on about whether or not four-wheel drive is an integral part of a winning prerunner or desert-racing truck. A look at today's SCORE Trophy Truck field reveals mostly two-wheel-drive vehicles, with notable exceptions found in the Herbst Smithbuilt Ford Trophy Truck and Dale Dondel's Chevy Trophy Truck, both of which are four-wheel-drive.
While it's true that most of the time you can get from A to B off-road in a two-wheel drive, if you have your front drive system engaged, you'll notice better lateral stability, since the back end is no longer pushing the front end along and sliding around when it gets the chance. Retaining four-wheel drive will allow you to explore more terrain than two-wheel drive can successfully get you in and out of. Two-wheel drive is cool until you're stuck miles from nowhere.
Check out Total Chaos Fabrication's four-wheel-drive Tacoma front suspension kit [www.chaosfab.com]. The TC kit provides 13 inches of travel with or without four-wheel drive. To save you the cost of custom axles, the kit is engineered around modified Tundra axles, which are longer than the stock Taco' versions. Your front track width will increase by 7 inches, which will aid cornering stability.
We'd keep the 4x4 truck even if you decide to remove the front drive components. Most 4x4s, Toyotas included, have stronger brakes, hubs, spindles, and wheel bearings than their 4x2 brethren. This is the case when comparing the Tacoma 4x4 with the five-lug Tacoma mini, aka Taquito.
Manual transmissions are generally more dependable, since they're less sensitive to heat. Shift-it-yourself gearboxes also let you hold a constant gear on long downgrades, which gives you better control and is easier on your brakes. Manual transmissions also transfer power more efficiently than automatics - the degree of power lost to drivetrain friction is called parasitic loss. Automatic trannies can change gears faster than even the fastest shift-lever hand and clutch foot. Since automatics shift quickly, you're less likely to lose momentum in critical situations such as deep sand and mud. Automatics also cushion the rest of the drivetrain using a fluid coupling, aka torque convertor. This cushioning helps preserve components downstream, such as driveshaft U-joints.
With a properly functioning transmission cooler, most automatics can live a long time, so in the end, it's a matter of preference. If it makes a difference, it's easier to eat and drive at the same time with an automatic - not that we do that.