Another symptom the new jacks corrected was when breaking camp and retracting the jacks, the "sticky" ones would cause a jarring drop on retraction, feeling like almost all pressure had to be released before the jacks would start to retract. There was also a "squealing" noise as they retracted (or extended). What really stepped up my complaining was a friend bought a new Coachman and when we'd go camping together and we'd be sitting outside, you'd hear our jacks popping and his were silent (and the exact same make/model jacks). You could hear ours from INSIDE his coach they were so noisy. Any Lippert jack making noise is one of the bad ones.