Maybe someone can help. I have a the 00 expedition with 200K. It has new ball joints, shocks and tie rod ends. I had P tires on the front and LT on the back but just took off the LT because it changed the handling and the ride. My problem is when I decelerate the front end shudders like I'm driving on rumble strips but its not the front suspension. It feels like the drive train. It does not happen when accelerating or at highway speeds. It also continues to do it even when I shift it out of gear and put in neutral. I am not braking when it happens. It was intermittent but now more consistent. Any suggestions?

 

Does it do it with the 4WD engaged?
Has anybody checked the hubs to see if there is any problem with them?
Did this start after the ball joints were replaced?

 

I didn't try in 4WD. It started before ball joints. What does a wheel bearing going bad feel like?

 

You may not feel anything with a wheel bearing going south, but you will usually hear from it first also it could trigger an ABS code if bad enough.

 

One more detail that may be important. Recently the service engine soon light came on. Mechanic replaced oxygen sensors but it wont stay off. Could the different height of the LT tires vs P tires have messed with the differential?

 

We don't have complete info here.
Do you know the exact reason the oxygen sensors were replaced?
With today's vehicles the two conditions could be related, but not enough info to even offer any suggestions. With electronics crazy things can take place that sometimes defy explanation.