2006 CTD 2500-swb-12kmiles. Question - when I go over railroad track crossings/wash board roads; etc.. `I here a rapid like thumping noise coming from under the right rear side and seems to be right under the passenger side rear seat; but on the outside underneath. Happens more if I have the quad in back. I have gotten underneath several times to look for signs tail pipe hitting and everything I can think of; but no luck. Have any of you guys experienced the same thing and/or know what it is?? Thanks

 

I wonder if its not the rear overloads you are hearing?

 

Its not. I get the same sound out of mine. Tends to do it more when I am shifting gear with the peddle in. Sounds like you broke the trans mount but all is fine.

 

I had a similar issue. I asked about it on a few forums and came up empty handed. It seems to have stopped recently.

 

Loose jack under the seat?

 

make sure your fold flat floors are lached down if it's a QC.

 

well when i bought my truck (used) the previous owner did not tighten the spare tire up all the way and it made a ruckis, it took a while but i finnally figgured it out. seems i look over the small things. good luck

 

Try some lube between the spring leafs if I'm not mistaken.Mine does the same thing sometimes and others have posted about this in the past.Trying using the SEARCH function as I know this issue was passed around a lot a long time back.But I think its lubing the springs.

 

I checked shock mounts, made sure elastic straps were secure for fold flat storage and lubed the leaf springs, nothing helped. I still get it from time to time, I will have to check the spare and also plan on checking all body mounting bolts especially the bed bolts. The tailgate is a bit loose so I thought that could be it for a while but some rubber pieces eliminated that possibilty.

 

Mine has a banging sound and it sounded like it was coming from the passenger side. Turned out it was my trailer hitch bouncing in the receiver.

 

I had the hitch rattle problem before but it is no more since I got this little guy. http://www.hitchrider.com/nowobble.htm