vibration and shudder when accelerating and slowing down

I have a 2006 4x4, 4.0, 6 spd, dcsb. It has a 6 inch lift on it. I started to feel a minor vibration when driving at highway speed about a week ago. It has gradually gotten worse, and today there is a pretty significant vibration/shudder when accelerating and slowing down. It is more pronounced and noticeable when slowing down. It doesn't matter if it's in gear or in neutral when I'm slowing down, the vibration/shudder is the same for both. It's not warped rotors, as I've already had those checked out at firestone. The tech there believes that it is something in the drivetrain. This sounds plausible, but I'm confused as to why it would happen when in neutral, and I'm slowing down. If I keep it in gear, and just remove my foot from the accelerator, and allow the truck to slow on its own from about 30 mph and below, the same shudder/vibration is present (both in gear and in neutral). The tech said he didn't see any signs of the wheel bearings being bad, so I'm confused as to what it might be. Clearly I need to take it to a shop that is more experienced in drivetrain issues. Just wondering if anyone else has experience this, and what I may be looking at in terms of repairs. Thanks in advance!

 

Driveshaft, center bearing or u joints

 

I had the same exact problem for the past few months. Two of my U Joints were seized, third was going bad, and the carrier bearing was going bad. Just got it all fixed last week and she rides like a dream now. Was like $400 at my local shop for all of them.

you’ll want to get it done ASAP because it will get worse over time. A single bad joint will cause the rest to start going out.

 

Yeah, you were spot on. The shop I took it to said they had to replace the rear u-joint as well as the carrier bearing. It still has a minor vibration, (although nowhere near as severe as it was) so I'm wondering if I should just go back and have them replace the forward u-joint as well.

 

You were spot on brother. Carrier bearing and u-joint.

 

How much did the repair set you back?

 

$575 for parts and labor

 

Not bad

 

yep, go get the rest changed(front as well)....and GREASE them at every oil change as well.....if one went bad, most likely due to lack of grease, the othera arent far behind.

 

Glad to help out brother, I wish I knew what that vibration in my rig was, blew out my driveshaft while driving cracked my charcoal canister. Changed almost my whole evap system minus the gas tank and lines and still have an evap CEL on.

 

Part of the maintenance scheme every oil change.