2000 GMC Sierra Half Ton Z71- The Ultimate Z71
Part V: Drivetrain
Sometimes it's all about the stuff you can't see. Without question the unsung heroes of most 4x4s are the hardworking drivetrain parts that translate power-namely your transmission and transfer case. When building a rig for the Ultimate Adventure, the goal is to make it as bombproof as possible. But bombproof doesn't always mean UA-proof. Remember, it's the Ultimate Adventure, not the sort of moderate "I will just trailer my rig from place to place if anything goes wrong" adventure.
With our '00 GMC Sierra 1/2-ton built from the factory with a driver-side drop configuration, we knew we were in for a bit of a challenge as our front junkyard Dana 60 axle had the differential on the passenger side. Now believe it or not, this is not as big of a challenge as you might think. Obviously your transfer case will need to be set up for the correct side, but the two biggest challenges generally faced with a swap like this is transmission width and engine oil-pan clearance. Working with a fullsize rig gives you more room to work around problems, and sometimes the solution is as easy as getting a custom driveshaft built. OK, I'm not saying that it's just that cut and dried, but if you are a confident fabricator with a bit of 4x know-how, it's something that you should have no problem tackling.
Keeping our Super Sleeper build going are Mel Wade and his squad of pro fabricators at Off Road Evolution. With the crew pulling out all the stops and kicking in the long hours, we geared things up with Off Road Design's NP203/205 Doubler and slid in a 15,000-pound Warn winch behind the GMC's modified factory bumper.
Check back next month as we wrap up our Ultimate Z71 build and show you some of the damage it survived. And for all of you who just can't get enough Z71 action, cruise over to our website, www.4wheeloffroad.com, for the entire series of web-exclusive extras that chronicles the build from the teardown to the Adventure.
Modern vehicle electronics can be a real pain when performing such an extensive conversion like we have done. Through a series of cut wires, swapped ECMs (electronic control modules), a disconnected BCM (body control module), and an eliminated four-wheel-drive module, we somehow tricked our truck into working. We wish we could retrace each step with you in the magazine, but our current configuration is a bit smog-challenged and we are still working out a few of the bugs. As far as we can tell, if you have disconnected the 4WD module (behind the driver-side dash) and the vehicle's speed sensor is monitoring only the reluctor ring that now rides on the transmission output shaft, everything should shift and work fine. Keep a look out for future blogs and articles that will address all these new-age electronic hurdles, and hopefully one of these days we can have a dash that will stop blinking at us!