1994 Ford F-150 4x4 & Ford F-350 Turbodiesel - Off-Road MailPosted in Features on September 1, 2002
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Transmission Swap for JeepHelp! I own a Jeep Cherokee with an I-6 engine and a broken five-speed transmission. From what I've been told by the Jeep dealer, there were three five-speed manual transmissions made for my Jeep: the T-5, the AX5, and the BA10/5. I think my Cherokee has the BA10/5, but I'm not sure. A friend has a T-5 out of a Camaro. Can I swap it in? If not, which of the other Jeep five-speeds can I use in my Cherokee?Harry GilbertsonRiverside, California
Harry, the T-5 and the AX5 were used mainly in Cherokees powered by the 2.5L I-4 and the 2.8L V-6 engines, although our sources tell us that a few 4.0L I-6 engines are known to be factory-equipped with the T-5 or AX5 trannys. However, most 4.0L Cherokees were equipped with either the BA10/5 or the AX5 five-speed manual transmission. The AX5 is generally regarded as the strongest transmission of the bunch, but the transmissions are not interchangeable, so the Camaro T-5 is out, unless you use an adapter from Advance Adapters.
Inline-Six Gear Ratio ChoicesI own a '94 Ford F-150 4x4 with 102,000 miles and the original 4.9L inline-six cylinder engine. It also has an automatic transmission and a Detroit Locker rear differential with 2.75 gears. I've recently installed a Rancho 4-inch suspension lift kit and 33x12.50R15 BFG Mud-Terrain tires on 15x8-inch Eagle aluminum wheels. After I installed the large tires, I really noticed a loss of power at low speed. I use my truck off-road a lot, so I really need maximum stump-pulling power. I know that I need to get new gears installed in the differentials, but I don't know which ratio is best for my truck. Like I said, I use the truck off-road a lot, so I don't mind really low gears. How low can I go?Larry ThompsonWoodbridge, Virginia
Larry, that 4.9L I-6 Ford engine is actually a pretty good mill, since it's relatively powerful at low rpm and a smooth runner because of the I-6 layout. The '94 engine made (when new) 265 lb-ft of torque at 2,000 rpm, which compares well to the F-150's optional engine, the 5.0L V-8, which produces 270 lb-ft of torque at 2,400 rpm. For gearing, we suggest you go with a 4.10 ratio for all-around driving; if you really want to maximize your F-150's low-speed grunt, you can install a 4.56 gearset. To install the new gears, you'll need a larger carrier or a new low-ratio Detroit Locker. With the 4.56 installed, the engine would turn about 2,800 rpm at 60 mph, which is a little high in its rpm range, but highly useable off-road.
Stopping Old SmokeyI bought a used Ford F-350 turbodiesel that was well taken care of, but there is something that's bothering me. The truck runs well and easily pulls my 6,000-pound trailer, but the engine seems to make a lot of smoke out of the exhaust pipe. The engine has 122,000 miles on it, but the Ford dealer told me that the diesel engines can typically last 250,000 miles. Do you think there's a problem with the engine?Lee GreenSeal Beach, California
Actually, Lee, Ford's turbodiesel has been known to emit a bit more exhaust smoke than comparable light-duty diesel engines. The first thing we'd do is take the truck to a Ford dealer for an inspection. If everything checks out and the truck still smokes excessively, contact: Hypermax Engineering, Dept. OR, 255 E. Rte. 72, Gilbert, IL 60136, (847) 428-5655, www.hypermaxengineering.com. Several years ago, Hypermax developed a new fuel pump specifically for the F-350 turbodiesel's smoking problem. The new pump limits fuel delivery until the turbocharger spools up and is producing sufficient boost during acceleration. Since the pump limits the introduction of fuel during low-boost conditions, smoke is reduced under normal driving situations.