I'll give it a shot
Bucknut Bob thank you so much but I still have many questions ? Maybe Y'all can answer another. Im originally from Florida and lived there until 6 years go when I moved out here to Western CO anyways I have always had Cars this will be the first 4x4 I have owned. Now I have been doing as much reading possible about my 4runner and finding out options but I still need to learn the Basics of a Differentals, transfer cases and how they work so if some one could please elaborate that would be awesome
Thanks,
Bear_F_ucker
I'll see what I can do to help, BF. An "open" diff provides power to both wheels as long as traction is equal, and allows the wheels to turn at different speeds (hence the name "differential") for cornering purposes (outside arc is longer, so that tire must go faster). The problem is when one tire starts to lose traction, the design transfers ALL power to the side with least resistance, and "voila!"...you're stuck. You can have one wheel on dry pavement, the other in a pile of snow, and not go anywhere! A limited slip diff uses friction to partially connect the two wheels during tire slippage, allowing for some power to still travel to the tire with traction, getting you out of mild problems. Limited slips also still allow full speed differential for cornering. They're a good choice for the front end of a street-driven off-roader, but not the best. A locker fully-locks the two wheels together, so that one tire can be in mid-air and the other one still has full power--what you want on the trail. They will differentiate for cornering as long as there's enough friction on the road surface, and you're not putting down too much throttle--you'll usually hear a clicking sound as the gear teeth jump over each other (perfectly natural). A locker on slippery roads can be a problem, though, because there isn't enough friction to make the diff open, so the tires will turn the same speed, and try to spin you. That's why a selectable diff is best for heavy street driving--open for pavement, locked for trails.
As for transfer cases, they're simple beasts. They "transfer" power, by means of gears or a wide mesh chain, to either one axle or both, or none in neutral (its neutral overrides the tranny, because it comes after it). Chain drives make for smoother operation, but they limit your options--you're stuck with the ratio you have, whereas gear drives can be swapped out for a lower gear ratio for better off-road use. High-range (4-HI) is one-to-one, meaning it doesn't change your overall gearing, and is what you use on the road mostly. Low-range (4-LO) multiplies your overall gearing by whatever the ratio is, giving you more more power for climbs, etc.. Off-roaders like to swap out the factory gears (Yotas are usually 2.28:1) for something like 4.7:1 or higher (which can only be done with the gear drive cases). This is possible even for heavy street driving because you don't use 4-LO on the street, so you won't know it's there until you select it. Transfer cases are handy for trail-damaged vehicles, as you can still get home using your front axle only (in 4wd) if your rear axle is disabled! Hope that helps, BF! :roadkill: