qc for flight safety
have a good look at the feel and centerung unite spring ' rollers and cams. if all looks normal go for a prper by the book lubrication. if still not same on botth sides you or one of ur people tuched a cable guord ' gromet or cable guide somtime back and only after few flts one noticed the difernt. cable run and close inspection will reville were is the problem. also if the the a/c was lately at basic maintenance a ballance panel seal which is not prperly installed may be the cause. good lock !