I just installed my 4" elbow and downpipe then had it connected to my Donaldson with 4" pipe. The Donaldson has been on there for a while with the 3.5" elbow and downpipe with no problems. Now my exhaust is vibrating like crazy at idle and gets even worse when you put it in gear, you can see the tailpipe vibrating. I checked all the hangers and the exhaust is solid with no rubbing issues and the vibration seems to go away when you give it a little gas to get it just above idle. It's like I have exhaust drone at idle which is very annoying driving around town at all these traffic lights. Anyone else seen a problem like this or know a cure?

 

Try neutralizing the exhaust... loosen all of the clamps and hangers, shift the engine from drive to reverse and back a few times (to flex everything) while the exhaust is loose. This will allow it to settle into place, then put the shifter into neutral and retighten the exhaust. Most of the time,(but not always) that will eliminate your exhaust vibrations.

 

I just put the donaldson on my truck the 51" 5" inlet version and I swear its me or the truck inside sounds like all the cheap interior plastic pieces got together and decided it was a dance party. I cant for the life of me figure out where all the buzzing is coming from but its driving me crazy. I give a little throttle and it stops.

I will be following this thread.

 

I have had that issue for a long time. Someone said that if you checked the front hanger, the one that goes into the tranny housing, if it is not centered in the hole it may cause the vibration. Didn't work for me. I have readjusted/replaced clamps, adjusted tailpipe, muffler, no go. Only solution that has worked for me is to put a rubber tie down on the tail pipe hanger and anchor it to my spare tire. Now I get the nice rumble you want to hear and not the drone.

 

Good suggestions guys.

My noise seems to be coming from somewhere deep in the dash as best as i can describe it. Maybe the dash is against the window somehow...Anyway its driving me nuts and I cant find the source.....Gggggggrrrrr

 

This worked for me, I loosened up both clamps on the elbow and the clamp on the downpipe that connects the pipe to the muffler. I tried just the elbow first and that didn't work so then I ground off the spot weld and loosened the clamp for the downpipe to exhaust pipe connection and tried it again and it is much better, close to what I had before. My hanger on the transmission isn't centered and I couldn't get it to but everything seems to be as it was before. Also the connection from the down pipe to exhaust pipe shifted just a fraction of an inch from what I could see with the spot weld that was placed on it.

Anyway Thanks a lot dieselfitter!

 

Cminus if you have an automatic check to see if maybe your transmission dipstick is contacting the exhaust, mine was real close and needed an adjustment.

 

Hey I will check that thanks....Never even crossed my mind.

 

I am having the exact same problem. Deep in the dash,,,, yep,, that is it! I will try fiddling with the exhaust hanger dealies.

On Edit - I have the same exact truck too.

 

Well i messed w/ the dipstick tube and low and behold the noise is gone!!!

Man I owe you a beer for the heads up thanks!