I suppose the servo could be damaged some how but no grinding noise or chatter when still. I've pulled everything but the servo saver, maybe that's the issue but I don't think so. I'm getting the same issue we get with an offset servo horn but the HPI manual says this 10deg offset is spec so I assumed it was in design to work correctly.
Turning left there is less range of travel than turning to the right.
so with just the servo saver connected the servos slow you mean mate ?
the 10deg offset is correct, but i take it everything had been set up by the previous owner before you got the car,
try taking the link off as i said before and work the servo with the radio to see if its slow one way,
then have a look at your radio and reset the steering endpoints to zero and check where the servo horn is,
if its straight up vertical then previous owner fitted the horn vertical and adjusted to the 10deg with the endpoints/trims,
make sure the servos at neutral with steering endpoints and trims in neutral position ,
then refit the horn at 10deg and try again to see what happens,
may still be a weak servo,
but also if you're trying to work the steering when the tyres are on carpet or grass then it will be slower,
tyres will drag on the carpet/grass and the saver will be turned a bit under the strain,
when the cars moving the steering would work fine, unless the servo savers adjusted wrong as well,
if thats the case then wind the adjuster screw in a turn or two on the top,but don't wind the screw too far or it will catch on the chassis underneath the saver, or get the manual out and reset the saver to correct tightness,
also, is your battery fully charged ?