Decent fix for replacing push nuts holding heat shield above transmission

[Crunch]

I don't know if anyone has ever had a problem with the heat shield between the floor pan and the transmission, but I just did. The other day I was doing a lot of driving on muddy ranch roads following a rain. The "mud" was mixed with a lot of gravel and rocks, had the consistency of mortar and seemed to be as hard as concrete when it dried. When I got back in town I noticed something hanging down underneath my truck. It was the heat shield, which had dropped where the transmission connects to the drive shaft. Fortunately, it didn't snag and rip out or get caught in the universal joint, but there was a fair amount of wear on the heat shield. I think rolling through several pools of water along with the mud slop spashing up there caused several of the plastic push nuts that hold it in place had fallen off. So I went to the Dodge dealer to see about getting new ones. The looked for quite a while, but couldn't find any. There is a number on the push nut--PA6, along with the letters "TRW". They couldn't find it in their computer, either. I did a basic Google search and had no better luck than they did. What did work, and seems to have worked very well is a fender washer backed by a wing nut. I started with a lock nut (1/4" - 20) and washer, but it only tightened a couple of threads so I figured it was metric, which turned out to be correct. Because of the location and length of the threaded post I decided not to mess with wrenches or deep sockets, and opted for 1/4" fender washers (about 1 1/4" in diameter) and metric wing nuts. The size for these posts is M6 - 1.0mm. I decided to replace all of them because after 15 years I figured those plastic push nuts might be getting a bit stretched and fatigued. If I get worried the wing nuts will loosen I might also put a drop of Loctite on the threads.

 

[Ozymandias]

Did this years ago too and used nylock nuts. A one for ever fix. Standard M6 Threads.

 

[BLNRAY]

pulled the oem insulating pad out of mine completely and covered the bottom of the cab with dynamat extreme,had the trans out so it was a pretty easy job.

 

[Crunch]

Did this years ago too and used nylock nuts. A one for ever fix. Standard M6 Threads.

I didn't think of nylon at the time because I was worried about excessive heat, and opted for wing nuts because I might not always have a deep socket in metric handy all the time. But that does sound like it will last forever.

pulled the oem insulating pad out of mine completely and covered the bottom of the cab with dynamat extreme,had the trans out so it was a pretty easy job.

Did you use the OEM heat shield as a template to match the holes, or did you find another way to attach it?

 

[BILTIT]

Dynamat sticks to surfaces so no need to attach.