tzh2231

One common issue of GX470 is the aluminum heat shield above your catalyst converter will rot over time and partially fall down and touch the muffler, then produce some annoying rattling sound when your idle and drive.

Today I spent 1 hour and fixed mine, and the first 55 minutes were wasted, so I'd like to share my experience with you to save you an hour.

The heat shield is a thin piece of aluminum board, or you can call it a heavy duty aluminum foil.
It is mounted on the chassis by 3 10mm bolt/washer. The hole for fitting the bolt is where erosion happens, when it gets too big to be hold by the washer, it falls down. So my first idea is to remove the bolt and put on a larger washer then screw it back. This turns out to be extremely hard due to the tight space. I spent 50 minutes to try to get it off but I did not even remove one of them (call me dumb).

Then I came up with a great idea ----- You do not really need to completely take off the bolt, just loose it up with 2-3 turns and then insert a home-made semi-open washer then tight it up and done.
You do not even need to lift the truck. It took me only 5 minutes to fix 2 bolts once I came up with the idea.

Here is how I made my semi-open washer:

Cut a large coin sized piece of HVAC aluminum board (available in every HD/Lowes) and cut a small opening to the center of the piece, then push it in between the old washer and heat shield, then re-tight the bolt.
Since the new "washer" is of same metal as the heat shield itself, and even thicker, I'd assume my fix would last at least 5-6 years if not more.

Hope this help someone here!