LTX 1040 won't pull but backs up good.

[Weedkiller]

The mower is hit and miss on pulling forward but seems to work as should in reverse. I've replaced both drive belts and three idler pullies replaced. It worked for a week and quit pulling. (It would move forward maybe 2' and stop) Guy came out, switched belts (again) pulled and inspected the variable speed pulley assembly and it looks and functions as should. It worked...for a week. Am I missing something? I'm about to go postal on it.

 

[StarTech]

It is possible the forward drive gear and engagement clutch are slipping in that single speed transaxle.