It's Time to Upgrade
Question: At what point should one consider an extensive axle swap before investing in what is already there? I've got a '96 short-box Ram. While the BFG Mud-Terrains continue to hook up everywhere, the 33 inches they offer is getting old. My buds with Jeeps on 35s are leaving me for dead. I am thinking about a set of 35- to 37-inch rubber. I think I have the necessary lift already and I'm not at all opposed to cutting the body up if it means keeping the center of gravity low. But I don't know whether to swap in a D60/70 combo from a 3/4-ton truck first, or work with the D44/Corp. 9.25 that came on the truck. I don't want to put a pile more money into the axles in the form of gearing and lockers, only to break everything and have to then do a swap. Some sources suggest that 1/2-ton gears are good up to 37 inches, and others warn to keep under 35 inches. I know that vehicle mass, tire size, engine size, driving style, and terrain all contribute to breakage
Zac V.
Petawawa, Ontario, Canada
Answer: Your 1/2-ton stuff is very tough, but 37s will be pushing them to their limit. Thereare certain thresholds of axles, and a stock 1/2-ton axle is OK with 35s. When built with custom chromoly shafts and lockers they can live up to 37 or 38, but that is dependent on the driving style, terrain, weight, and so on. Unless you are a 110 percent positive that you will never go larger than 37-inch tires and you will never drive aggressively, I would take the step up to larger axles. Follow your lan, keep it low, trim the body to fit, and get those bigger axles under there.
Leaky Slushbox
Question: I have a '99 diesel Ford Super Duty 4x4 with an automatic transmission that was replaced by Ford on an earlier recall program. This replacement automatic transmission occasionally leaks automatic transmission fluid but only when the truck is in four-wheel drive! Sometimes the volume of lost fluid is so great that the automatic transmission will start slipping. If I replace the lost transmission fluid-normally about 5 to 6 quarts-and drive in two-wheel drive this stops all further leakage. I can drive thousands of miles in two-wheel drive, pulling heavy loads and in hot temperatures and it never has leaked a drop. The repair shop has suggested pulling the automatic transmission and replacing the seals on the automatic-transmission fluid pump. However, I suspect the pump seals are not bad if the automatic transmission does not leak fluid while in two-wheel drive! Have you heard of similar fluid leakage problems? Could this be an overheating problem related to the use of four-wheel drive, which puts a heavier load on the transmission and causes the fluid to be lost?
Ronald M.
Florence, AL
Answer: That is a pretty crazy situation you have there. My first suggestion would be to take your truck to the local pressure washer and get it spic-and-span clean underneath. Then take it off road and when it starts leaking, crawl underneath and figure out exactly where it's leaking. I spoke to Brian Thompson from Brian's Truck Shop (870.422.3673, www.brianstruck shop.com), where they specialize in Ford transmissions, and he said that the transmission should not care whether you are in two- or four-wheel drive. Any line pressure increases due to being in four-wheel drive would also be seen in two-wheel drive. In the end we came up with only two scenarios. First, you might have a broken bellhousing. If it is cracked, the additional twisting of the drivetrain while in four-wheel drive may be causing a leak. However the second scenario is more likely. You are heating up the tranny considerably more when driving off road. Do you have big tires, yet still have the factory axle gearing? If so, this is putting more strain on the transmission, and if you are going slow but working the tranny very hard, you are probably not getting enough airflow to cool the transmission, thus the overheated fluid is getting pushed passed that seal. I would recommend a few things once you determine where the leak is coming from. Change your gear ratio in your axles to better turn the bigger tires, get a bigger tranny cooler or add an additional fan to help cool the gearbox, and get that pump seal replaced. Brain is just up the road from you in Arkansas and would gladly help you out if you're interested.
Final Question
Question: I have an '87 Samurai that won't run smoothly, and is multicolored and rusty. I think the carb might be plugged and the battery is dead. Do you want to buy it?
Shad
via 4wheeloffroad.com
Answer: Nope. Thanks for writing.