My NP241 just started making noise when I have the truck in 4WD. It sounds like someone trying to drive stick that doesn't know how. The truck every once and a while will give out a loud wine like someone trying to shift without using there clutch but it only lasts about 2-3 seconds at a time. Could it just need a linkage adjustment or could the little plastic boots that are on the end of the fork inside be gone?