Stumped on Sumps
Question: I am in the process of building a rad rock buggy. I don't have much money or tools, but I have a lot of time. I am running a 4.3 Vortec out of my mom's old Blazer that started on fire (cigarette, Pabst BR, the dog, long story). I am having a problem getting the oil pan to clear my Dana 44 that I converted to eight-lug to match my Eaton rear axle. I need to know which one of the vehicles that used this engine will have the shallowest or shortest oil pan. I really want to get my buggy going because I have a hot date with the girl up the road in a month or two and she seems to be into the buggy thing. She drives a really cool Forward Control Jeep, and I think she likes me.
Brian E.
via 4wheeloffroad.com
Answer: There are two basic factory oil pans, steel and aluminum. If you have a steel pan you need to replace it with another factory steel pan, and the same goes for the aluminum. However, there are also differences in the depth depending on whether the pan is from a two-wheel-drive or a four-wheel-drive. The four-wheel-drive is very shallow at the front, but very deep in the rear and uses a small sump, where the two-wheel-drive is shallow the whole length, but not as shallow as the front of the four-wheel-drive. You'll most likely be better off with the two-wheel-drive version of the aluminum pan since yours is a Vortec engine.
Fake Locker?
Question: I was told that my new four-door Jeep JK has lockers (it's not a Rubicon model), but it seems like I get a lot of wheel slippage climbing hills. It makes it to the top OK, but shouldn't a real locker really lock, not spin?
Henry D., MD
via 4wheeloffroad.com
Answer: You're right on. A real locker does lock, not slip. What you have is a system known as Brake Traction Control, and theoretically it could be called a locker, but it isn't. A locked or a spooled differential allows both tires on one axle to turn at the same time and rotational speed, regardless of traction, even if one tire is in the air. Brake Traction Control (BTC) and all of the various names for the same system from different manufacturers control traction by applying the brake on a selected wheel to force the power to the other wheel through an open differential. That's correct, you have an open differential, which on an ordinary vehicle means that if one tire is in the air or slips due to lack of traction, the other tire remains stationary and you are stuck. Now enter the magical BTC; by sensing wheel speed (since the vehicle has an Antilock Braking System) the computer knows that one tire is spinning faster than the other and clamps the brake down on the spinning tire proportionally to transfer power to the nonspinning tire which has traction, and up the hill you go. However, the drawbacks of this system are numerous, even though the technology is slowly catching up with the design parameters. While the engineers can make wonderful graphs and models to show the bean-counters why this is a good system as well as convince the marketing people that stupid consumers will be able to use this instead of a real locker while the lawyers all nod in liability-proof agreement, the fact remains that for the system to work (regardless of the threshold parameters), the tire without traction has to slip while the other tire remains still for the BTC to engage, hence a loss of traction and even more spinning. The way to drive these rigs is counterintuitive-as you have to give the vehicle more power to make the other tire pull, by breaking the spinning tire which forces the other tire to spin. Early versions (and some current ones) from various manufacturers are simply hideous, as you have to keep gassing the rig until it hooks up and lurches over an obstacle, and hopefully not over a cliff. As far as we're concerned, they aren't lockers.
Wrong Wheel
Question: I have encountered a slight dilemma concerning my choice in wheel size for my '04 Super Duty diesel 4x4. When I bought it new in 2004, I put a set of 16.5x12 Weld Mountain Crusher wheels on it. Now I'm finding it very difficult to find tires that fit them. I've been running 16.5/36/16.5 Cepek Fun Country Kevlar for the past couple of years. Do I need to opt for new tires and wheels this time around?
Tony A.
via 4wheeloffroad.com
Answer: The 16.5 wheels and tires are quickly becoming a thing of the past. Though these wheels and tires have been around for a long time, the new 17-, 18-, and 20-inch wheels are quickly replacing them, and they are better wheels. The 16.5 wheels often do not have the small safety bead that helps keep the inner bead in place, thus they are more likely to lose a bead when run at low air pressure off road. I do, however, like the military surplus Humvee wheels that are 16.5 and double bead locks, but otherwise I wouldn't spend any more money on 16.5s. There are a ton of great tire options for 17-inch rims and I would recommend you upgrade to them.