Dewalt DC920KA Heavy Duty Xrp 18V Cordless Drill/Driver "put drill hammer mode" Questions

HAMMER MODE SLIPS OUT WHEN I PUT THE DRILL INTO HAMMER MODE IT SLIPS INTO A NEUTRAL MODE ,BETWEEN HAMMER AND DRILL ICON i am guessing the transmission problem not enough tension to the clutch

how do I put a Dewalt DC988 hammer/drill in hammer mode? turn the selector lever from hammer / drill to hammer it is a second lever close to the gear box of the drill

...drill Hi when I put pressure on the drill in hammer or screw mode or just hold the chuck the clutch slips .help please this is the fourth one of these to do this. Regards Kevin what is the setting in ...