Tonight I had to haul a load of water. This is the first load after installing the dd3's. I noticed an aweful vibration/sound that rumbled throught the truck when acceleration occurs. This is when you really get into it. When you ease the throttle it dosent do it. <br><br>I still have the stock exhaust to the five inch stacks. I was thinking it was too much exhaust trying to push out the small pipe. I thought this because when it did the before mentioned it was pouring smoke out the stacks. When eased into, there was no smoke, and hence no noise/vibration. &gt;<br><br>What do you think?

 

You have an auto or a manual? If auto, you might be slipping the TC. If auto you might be slipping the clutch. You said it only happens under hard acceleration, right?<br>Not that I actually know anything, but that's my 2 cents. <br><br>Chris

 

I havent talked to him yet. <br><br>This is a new South Bend. It has over 800 miles on it. So I dont think thats it. I checked all fluids and everything<br>is ok. I still think its having trouble getting rid of the combustion.

 

My guess, and its only a guess, is that you have a U-joint that is starting to go out. I had the same thing happen to me on my 2000. It would only vibrate under a load ,and then only when accelerating. I could never find the problem, would crawl under the truck and shake the drive shaft and it would not move, finally got mad and drove home one day in a speedup and slowdown motion. By the time I got home (20 miles) was able to see the bad U-joint.

 

Thanks Big foot. I will check that tonight. It is funny that it happened after the injector install. It might have <br>been going out for a bit. :

 

It may have been slowly going bad, but it may have taken the extra torque to put enough strain on the u-joint to make it shake. Maybe.

 

Thanks you all. Sometimes if my mind would work I would think of things. Glad you guys are around to think for mwe.

 

HG, you're probably just in &quot;school mode,&quot; and thinking like your students ;D Happens to me all the time.