Hello Ray & Tom,my question is,I have a 1999 Jeep Grnad Cherokee Limited,the door lock on the passenger side makes a grinding noise when the lock engages manualy or when the vehicle reaches 15 mph.It sound as if it’s a plastic gear that 's making the noise,belive me I’m not afarid too pull it apart too see if it’s the grease that had dried up,anyway I’m just woundering if that could be the trouble.
Thank you for your help,
Leon
Yep, remove the door panel and closely inspect the movement of the linkage as you lock and unlock the door.
Be careful not to rip the plastic moisture barrier though. It is glued on to the door but can be placed back on the door intact if done carefully.
It would be beneficial to service all moving parts while the panel is off.
Remove and clean the electrical connections on the power door lock actuator too.
Lube the window regulator and check the track for binding.