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The traction drive belt on your John Deere LT180 lawn tractor is adjustable by loosening the nut on pulley #25 and sliding it away from the engine drive pulley. More then likely if you are experiencing any kind of belt slip the belt needs to be replaced. The following steps will lead you through the belt replacement process.
1) Engage the parking brake and start by removing the mower deck.
2) Set the deck height setting to the lowest point and lower the deck all the way.
3) Remove the quick pin that retains the deck engage link from the deck, be careful not to loose the washer.
4) remove the two retaining pins at the rear of the deck and return the deck raise lever to the raised position.
5) Push the deck froward to relax the belt and unhook the front deck hanger.
6) Carefully work the belt around the belt guide on the engine pulley and remove the belt.
7) The deck should not slide out from under the the tractor.
8) Start removing the drive belt guides by loosening the nut retaining #31 in the diagram.
9) Loosen the nut retaining pulley #25 (mark its previous location in the slot for installation) and slide the pulley towards the engine pulley.
10) The belt should now be loose enough to work around the rest of the belt guides and off the front and rear pulleys.
11) You may need to remove the steering rod from the actuator end to get the belt off.
12) Simply install the new belt in reverse order. Be sure to check for rubbing belt guides after installation, some may need minor adjustments.
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Edited by Kevin on 6/8/2010 at 11:24 PM EST