Thank you for your question.
I am sorry you are having a problem with your tractor. I should be able to help you. I have added an image below showing how the belt should be routed on the mower. First, make sure the belt is routed correctly. If it is, I recommend having someone sit on the tractor with the engine turned off. Then while you are watching the idler arm on the deck, have them lift the engagement lever. You should see the idler arm on the deck move and tighten the belt. If the idler arm is not moving, verify all the linkage is connected. If they are I suspect the idler arm is rusted. To cure the problem I recommend removing the deck from the tractor and loosen the idler arm bolt. Then spray the area with WD-40 and move the arm back and forth. Once the arm moves freely slowly tighten the bolt while mowing the arm. If the arm is still free, go ahead and reinstall the deck. Then check the operation. I hope this is helpful.
Please let me know if you need further assistance.
Here is a link to order any parts you may need.
Sears Parts Direct
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services
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