A slide rail assembly adapted for engaging a drive track of a snowmobile. The slide rail assembly comprises a rail adapted for engagement with a rear suspension system of the snowmobile, and aligned forward and rear slide portions disposed on a lower surface of the rail adjacent the drive track. The forward and rear slide portions are respectively located on forward and rear portions of the rail. The rear slide portion comprises a first material and the forward slide portion comprises a second material, the second material having a hardness which is less than that of the first material. Noise and vibrations resulting from contact between the drive track and the forward slide portion are attenuated by the second material.