MTD mows good most of the time but occasionally the mower will not be able to pull itself uphill even small inclines especially when the grass is wet. I can drop mower in lower gear and it helps. I can also "pop" the "clutch" (not really) and it seems to do better.
All belts are working but the mower is 7 years old and I have never changed either drive belt. Could this be it? How do you know? Could it be a tension spring on an idler pulley?