How do you change the muffler on a John Deere stx38?

Answer 1

Your STX-38 should have either a 12.5 or a 13 HP Kohler engine. Those engines have two studs that hold the exhaust to the engine. You should be able to pop the two springs loose on the hood hinge and take the hood off by un-hooking it from the 2 hood support brackets. Once the hood is off you will easily be able to see the two studs for the exhaust on the front side of the engine.

1. Remove the two 13mm self-tapping screws holding the main heat shield and set the heat shield aside.

2. Remove the LH [as you're facing the motor] hood support bracket [10mm] and put it aside.

3. Remove the smaller heat shield on the RH side [2 bolts, one 7mm, one 8mm] and put it aside.

4. Remove the 2 lock-nuts holding the muffler to the frame [13mm].

5. Remove the 2 flange nuts holding the muffler to the exhaust flange [13mm].

You should be able to slide the muffler out of the hole in the frame now by wiggling it a bit.

Reverse the steps to re-install after replacing the flange gasket.