dynomax update

Back in a Bowtie · September 21, 2015

So i believe the saga is finally over. I originally bought my dynomax vt cat back kit through CARid and boy was that a nightmare. Got the kit installed and loved it till it developed a rattle at cold start. Called dynomax and they sent me a new muffler no questions asked, gotta give them credit there. So the new one comes and i switch it out and still it rattles in the morning. So I contact dynomax again and they offer a full credit, just have to send the kit back. Didn't want to do that so i decided to fix it myself. Found a fix online that some guy figured out. Basically running a screw up through the bottom of the muffler to the valve to prevent it from making contact with the inner walls (leaving it open slightly at all times). This worked great and even after not driving the truck for a few days i get 0 rattle. Now its not something i should've had to do. Dynomax should've made a product that works but hey, i didn't have to take the exhaust off and it was an easy fix.

Rawyzf · September 21, 2015

Nice work!

tnchevy · September 21, 2015

Mine never did rattle but looking at it before I put it on I can see how eventually it would. It has some sort of dampener on the back side of the valve that would probably work its way loose.

robvas · September 21, 2015

I would never want an exhaust with moving parts. Ugh.

Half_ton · September 22, 2015

Is it possible you take better pictures of where you put the screw? Also what screw length you used. I have the same issue on cold starts and it drives me nuts, i'll never admit it to my wife because she told me, "You always have to modify everything you buy, can't you just leave it alone?"

any help is appreciated.

Back in a Bowtie · September 22, 2015

Is it possible you take better pictures of where you put the screw? Also what screw length you used. I have the same issue on cold starts and it drives me nuts, i'll never admit it to my wife because she told me, "You always have to modify everything you buy, can't you just leave it alone?"

any help is appreciated.

Its 7 inches back from back end of the body of the muffler on the seam. I used a 1.5" stainless self tapping screw (but it was easier to drill the hole first). I drilled through the bottom and then as straight as possible drilled through the inner pipe. Then i used a small allen wrench to make sure i was in the correct spot (push up through and feel the valve moving) Then run the screw into place and weld it up.

NOTE: this image is upside down. I did this from the bottom side of the muffler while it was on the truck

let me know if you have any other questions

Half_ton · September 22, 2015

the top picture has the axle on your right hand side?

Back in a Bowtie · September 22, 2015

the top picture has the axle on your right hand side?

top picture was taken via the face time camera facing the sky. Not sure if theres any mirroring involved but if not the axle would be to the left. the 7" measurment is really the only crucial one. other than that just center up and your good to go. The muffler should be seam down with the offset side closest to the frame rail.