John Deere M155560 Deck Drive Lift Arm X300 X304 X310 Select Series Tractors

If your Deere tractor is breaking belts then you need to replace the tensioner arm ASAP. As the tractor hits 200-300 hours the tensioner arm starts to wobble and kick the deck belt off the pulleys. This will break/damage the belt. Replace the arm and then install a new belt and it should fix your issue.

Great replacement arm for John Deere

Bought this as a replacement to go on my 11 year old X300, it works great and stopped the belt breaking issue I was having. Fast shipping, great product at a good price!

Part installed and works fine; however, part manufactured with rough and sharp edges, unlike overall quality of original.

Not too many options available for this part but it is necessary. The center pivot hole begins to wear in an egg shape causing oscillations in the belt train. The part appears to be made from a softer material than the bushing so this part wears faster, resulting in broken belts when the oscillations become intolerable. Note that keeping the blade pulley spindles frequently lubricated will minimize the strain in the belt train system but the life of this part seems to be around 200 hours at best.