We love surprises, as long as they're the good kind. The nasty ones we can do without. You'll probably agree that an example of a nasty surprise is any sort of transfer-case failure. Since our Fiery Redhead Project F-150's odometer has twirled around to the tune of more than 150,000 miles, we felt that its transfer case could be poised for failure. We based this speculation on not only the truck's high mileage, but also on the fact that we had no idea as to how the truck's previous owner maintained it.
The T-case seemed to work fine, but we're not ones to tempt fate. So we had it professionally rebuilt. Like the transmission rebuild in last month's issue, we opted to rebuild the unit that was in the truck, as opposed to replacing it with an aftermarket unit. This gave us an opportunity to see for ourselves what kind of shape the unit was in, and we'd get to see how the new parts compared with the old.
Motive Gear knew exactly what...
Motive Gear knew exactly what we'd need to rebuild our BorgWarner 1356 transfer case, and they sent us a variety of new parts, including an input shaft/carrier assembly, a high/low shift hub, an oil-pump assembly, a four-wheel-drive shift fork and a bearing-and-seal kit.
The first thing we did was dial up the folks at Motive Gear. They're a massive wholesale supply house in Chicago that provides parts to thousands of jobbers, and they stock all the parts needed for a rebuild of this caliber. They're quite knowledgeable about transfer cases, so they immediately gave us the lowdown on what parts tend to wear in our Borg-Warner 1356 T-case, and what we'd need to rebuild it correctly.
They shipped the parts directly to the shop that would be rebuilding the 'case, Big Gun Racing Automatics in Blackwell, Missouri. Big Gun owner Matt Heady is not only experienced in building heavy-duty automatic transmissions (he has built 'em for Bigfoot, Sudden Impact, Summit and Nitemare monster trucks), but he's also a master of transfer-case tech as well. He's been building transmissions and transfer cases for customers all over the U.S. for more than 18 years.
Surprisingly, our F-150's transfer-case internals were in reasonably good shape. Once unbuttoned, it was obvious that the unit had been wrenched on in its lifetime. Nonetheless, we installed all of the new parts. Now we have the peace of mind that goes with knowing that our transfer case is ready for years of service.
The following photos will give you an idea of what components tend to wear in the BorgWarner 1356 T-case and what parts are available in the aftermarket to remedy these problems. Some are normal wear items, while others are not. You'll also see how easy it is to remove and reinstall the transfer case yourself so you can save a few bucks.
The 411 on the 1356
Ford began using the BorgWarner 1356 in 1987 as a replacement for the BorgWarner 1345. The 1356 boasts a tough magnesium case, respectable 2.69:1 low-range ratio and chaindrive. When compared to the NP208, the 1356 has a much larger chain, and when placed side-by-side with the NP205 it measures 6 inches longer.
To remove a manual-shift transfer...
To remove a manual-shift transfer case, begin by removing the driveshafts. Drain the fluid, disconnect the shift linkage, vent hose and the 4WD indicator-switch wire. Then you can remove the six bolts connecting the transfer case to the transmission. Some of these bolts are difficult to access and may require removing the exhaust pipe or using a swivel socket to make the job easier.
With the six mounting bolts...
With the six mounting bolts removed, the transfer case can simply be slid off the transmission output shaft. With the transfer case out of the truck, Heady completely disassembled the transfer case on the bench and cleaned all of the original components in a high-temp parts washer.
With the transfer case apart,...
With the transfer case apart, we could see how the internal components were wearing. Inside the transfer case are two shift forks. Both have wear pads, and these pads need to be inspected closely. If they're worn, the transfer case can be hard to engage in four-wheel drive and/or 4-low, and/or they can cause the unit to pop out of gear during use. If they're worn, the shift forks are replaced with new units. Ours were in good shape, but we replaced the four-wheel-drive fork with the new unit anyway.