general problems of the 2005 Nissan Titan

Nissan Titan purchased in March, with approx 4,000 miles the truck began to shake when braking. The truck has 5,00 miles now and shakes severely when braking on a downhill grade and manuevering curvy roads. It was difficult and I beleive unsafe to travel any longer with this vehicle. When the local dealership was notified of the shake/shimmy they informed me of a waiting list for parts and stated that they new exactly what the problem was, that all dealerships in the area have a waiting list for this part and that it was safe to drive the vehicle. I disagree. Living in an area with hills and curvy roads it is not safe to operate this vehicle. I will not be driving the Nissan Titan until it is repaired. I did not hear of a recall and was surprised to know that the secretary at the service desk knew exactly what my problem was without anyone looking at my vehicle. This could endanger lives.