|Fall Auto Rally 2001
held at the Volo Auto Museum -- Volo, Illinois
by Rick Smith
The GMC Sierra is an impressive vehicle. It can seat five, tow a large boat and hold lots of cargo. With Quadratrac steering, this huge behemoth can turn around on a two lane road tighter than the BMW M3!!
While large features in trucks are needed for hauling and carrying, their size makes them "handle like trucks", so making a U-turn is nearly impossible, without using four or more lanes. With the Quadratrac 4 wheel steering option, GM has create a large truck that is easier to drive. GM says Sierra has the turning radius of a Saturn sedan -- quite impressive.
Rear of this vehicle
All the four wheel steering work is done under these fenders
Here is the rear wheel in normal 2-wheel steering mode
the rear wheel turning in the opposite direction on a left turn (rear wheels are turning slightly to the right)
the rear wheel turning in the opposite direction on a right turn (rear wheels are turning slightly to the left)
The right side control arm and hydraulic piston used to control the angle of the rear wheels
Left side control arm
Since the Quadratrac four wheel steering system is implemented simply, using hydraulic cylinders, it should be quite reliable and easy to maintain. The results are quite impressive. I would advise any men out there who want a truck, but have wives giving them "flack" because the trucks they want are "too big" or "too hard to handle", should check out the GMC Sierra. With Quadratrac, she might like to drive this massive truck better than a smaller SUV.
Dated: February 3, 2002 (updated September 2002)