Time to replace the 4 tires on out fiver as they ar 6 years old... We have the Goodyear Marathon G614 tires LT235/85R16 "G" and have had no problems with them... The place I go for tires is main...
I would start looking for a new tire dealer that is honest and not pushing his Chinese JUNK. The G614 is not a Marathon series tire. There was a time a few years back that Goodyear had some problems with the G614, but the problem was fixed and they have proven to be very good tires. Like I said...find a new tire shop.