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Old 03-27-2013, 02:24 PM   #91
Calamity Jesus
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Join Date: Oct 2003
Chapter/Region: NWIC
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Originally Posted by quentinberg007 View Post
What do they use to lock those planetary gearsets? Clutch packs, locking pawl?
Probably a pawl... it already has a wet clutch to handle lateral locking. I like the idea.. it means the driveshaft can be lighter since the extra torque is going to be limited to the diffs and axles. My only concern is what will happen when you engage 'low-range', one malfunctions and the other doesn't. I guess the PTU (basically what the Active AWD Subarus employ to send power to the rear axle) will simply slip and the TCU could throw it out of low range again to protect the PTU.

Jeep Active Drive I uses a power transfer unit (PTU) which has yaw correction, balanced torque distribution, and brake traction control; it improves both understeer and oversteer. The system uses a fully variable wet clutch in the rear drive module, which supplies the proper amount of torque for either slippery roads or high performance, interacting with the electronic stability control (ESC) system when needed.

Jeep Active Drive II includes a two-speed PTU with torque management and a low range. Specifying low range locks the front and rear drive shafts, and adds a 2.92:1 gear reduction for better climbing; crawl ratios for severe off-road conditions are 56:1 with the four-cylinder and 47.8:1 with the V6, up to 90% higher than the Liberty. Jeep Active Drive II works with the Selec-Terrain system to modify torque distribution, calling in the stability control system as needed.

When in neutral, the 2014 Jeep Cherokee with Jeep Active Drive II disconnects the driveline for flat towing behind another vehicle.
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