Any Road. Any Time.

The 1999 Isuzu Trooper, the most convincing argument yet that life is indeed too big for cars. Perhaps the perfect blend of luxury and performance in an SUV, Trooper combines a breakthrough traction system, expansive interior, powerful engine and 15 years of proven capability. Travel wide. Travel far. Travel most anywhere in the Isuzu Trooper.

With Trooper, a luxurious feel doesn't come at the expense of honest-to-goodness off-highway capability. Pick out a parcel of wilderness you've had your eye on, because Trooper is built to handle the kind of adventures that can't be confined to a road atlas.

Trooper's standard electronic shift-on-the-fly system lets you engage four-wheel drive while driving at up to 60 miles per hour. One push of the dash-mounted button instantly gives you 4-wheeled traction.

Trooper's Shift-on-the-Fly Four-wheel Drive

In part-time 4WD vehicles without "shift-on-the-fly," the driver must stop to lock or unlock the front hubs. To provide four-wheel drive on-the-fly, Isuzu engineers use automatic free-wheeling hubs attached to the front axles.

This approach could normally cause damage to the front differential, because when free-wheeling in 2WD, the front differential still needs to be disengaged from at least one of the front wheels. However, the Isuzu design avoids this problem because it incorporates an innovative split in the left front axle to disengage the left front wheel. This split can be opened or closed, using a special splined engagement sleeve. This sleeve can be locked into place to reconnect the axle for 4WD operation, or can be retracted for 2WD free-wheeling.

To engage 4WD, at speeds up to 62 miles per hour, the driver moves the transfer case lever from Two High to Four High. A new triple-cone synchronizer in the transfer case enables the gears to mesh while in motion. Once a sensor in the transfer case verifies that both the left and right front axles are spinning at the same speed, a vacuum actuator slides the splined engagement sleeve into place, closing the separation and locking the left front axle together with the right front axle and the front differential. When this happens, an in-dash light illuminates, confirming the vehicle is in 4WD.

The entire "shift-on-the-fly" sequence happens in less than a second.