Is there a way to adjust the wheels to tighten the drive belt for a 42" cutting deck? So far I have been replacing the belt every year this year the new belt will not turn the blades.

Adjust the idler rod connecting engageing handle to the deck.longer or to frount of mower is tighter.

Try replacing the belt.have the belts overall length measured.any good mower business can do this.purchase a belt that is 1/2 -1 inch smaller in size.if the deck is engaged by electric pto switch,it is normal to replace the belt every other season.lube the deck spindles if it has grease zerts.with belt removed from deck spin blade mandrels by hand and listen for any noise,such as grinding.if the bearings are good the mandrel should turn one to two revolutions,if they turn free the mandrels are locking up and breaking belt or stretching belt.owner of mower repair business,45 plus years experience.gibsonmowerrepair.com