HRNGTN Posted May 2, 2008 Share Posted May 2, 2008 I Have a 08 Highlander sport 4wd , the owners manual does'nt tell you anything and the dealer says its automagic. Does anyone have any info on how the 4wd system works. Thank you Quote Link to comment Share on other sites More sharing options...
humanoid Posted May 3, 2008 Share Posted May 3, 2008 Highlanders 4WD system is a full-time all wheel drive system and is always in use. It incorporates a center diff. with a built in viscous coupler, in which, limits slippage when the computer senses the tires slipping or losing traction. There is no levers to pull nor buttons to push. In actuality, it should be called all-wheel drive and not 4-wheel drive. So your dealer did not really deceive you, it really is automagic. Here's another explanation: "Full time four wheel drive" sounds more rugged than "all wheel drive" so the former is often used to describe the system in SUV's. When driving all 4 wheels on dry pavement, a center differential is used to split the power between the front and rear axles intead of a transfer case. A center differential can vary the amount of power transmitted to the front and rear axles, while a transfer case splits the power evenly. The transfer case's even power split can cause premature tire wear and drivetrain binding on dry pavement so it is not practical in permanent 4WD applications but they tend to be more ruggedly built than center differentials. There are many variations of the AWD theme, like center differentials that lock or have viscous couplings, but they all allow variation between the front and rear axles. Quote Link to comment Share on other sites More sharing options...
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