1981 Toyota Pickup Transfer Case Buildup - The Phoenix Project Shifts To The LeftPosted in How To on November 1, 2008
Last month we got our Phoenix Project's transfer case doubled, only to tear it down anew to install Inchworm Gear's Lefty adapter. "Lefty" is an adapter that fits Toyota's '79-'95 transfer case used with factory four-cylinder applications. Lefty replaces the third layer (counting from the back) of the transfer-case assembly, shifting the front output from the passenger side over to the driver side.
Relocating the transfer case's front output can be useful for several applications. The foremost use of Lefty is to help provide double transfer cases for Tacomas, FJ Cruisers, and '96-and-later 4Runners. These trucks have a driver-side front differential from the factory. Lefty allows double transfer cases without requiring a solid-axle swap (using a front axle with passenger-side differential) at the same time. It should be noted that additional adapters, such as Inchworm's Prerunner Adapter, are required to mate the Tacoma transmission and transfer case to the front of a '79-'95 geardriven transfer case. Lefty can also be used in non-Toyota applications. We've never heard of anyone using a Toyota transfer case in an early Bronco or Jeep TJ Wrangler, but with Lefty and the proper tranny-to-transfer-case adapter, you could. Mentioning such applications may make Jeep and early-Bronco purists turn purple, but the point is that Lefty makes the rugged, plentiful '79-'95 Toyota geardriven transfer case a viable rig-building option even outside of the Toyota world. Inchworm "clocked" Lefty upward, creating a nearly flat profile for the bottom of the transfer case. Normally, clocking a Toyota transfer case also clocks the transfer-case shift lever, but Lefty leaves the shifter in its stock vertical position. Lefty can be used in conjunction with either a single- or a double-transfer-case system.
At first blush, using Lefty seems an odd choice for an '81 Toyota pickup build. After all, this truck was factory-equipped with a passenger-side-diff solid front axle. Furthermore, the stock 22R engine has the exhaust on the driver side. This makes for potential fitment problems between the exhaust system and a driveshaft on the driver side. If the rest of the drivetrain were staying stock, Lefty wouldn't make sense as part of the Phoenix Project. The rest of the drivetrain isn't staying stock. As such, it's out with righty and in with Lefty!
Last time, we had just begun Lefty's installation. Follow along as we finish up.
Assembling Lefty is straightforward, but the job requires a shop press, grinder, drill, heating torch, assorted handtools, and the patience and expertise to do the job correctly without damaging the parts. This is also an ideal time to replace any worn bearings and seals inside the transfer case, and you'll need bearing pullers and seal pullers to do that job correctly. Air tools are not mandatory, but they make the job easier on the arms and the knuckles. The expert hands of Jay Parodi at PDC Motorsports led the way through the installation process. Should you attempt the installation yourself? Only you can decide, but be honest with yourself when choosing DIY versus handing off the job to a pro. This isn't rocket science, but it's much tougher than changing your oil or bolting up a new set of shocks. Once you've torn your transfer case down to this point, you're ready to start installing Lefty.
External snap rings provide lateral location for the bearings inside the case. As delivered, these two bores were undersize, requiring Lefty to be pounded or pressed onto the bearing's outer races. Reid at Inchworm Gear explained, "We've seen some variation in the outside diameter of the bearings, and we don't want to have the bearings spinning inside the case, so we machine the bores on the tight side." The bearings on the Phoenix Project's 'case were way too tight, so we sanded the inside of the bores until we achieved a factory-like slip fit. Care was taken not to remove too much material or sand the bores out of round. The fit was checked often by pounding the bearings (using a urethane mallet) through the bores to determine where and how much sanding needed to be done.