hey, im hoping that someone out there has had the same issue as i have and fixed it... my door locks on both my doors just about need to be beat on while unlocking for the key to work. it really gives me issues when it rains or is cold out. im wondering if i might fix the issue with some white lithium grease around the lock cylinder but was wondering if it might be something else with the lock or even the key. if anyone else has had the same issue let me know what you did to fix it. btw, it is a 1999 f150xl manual locks.