deceleration vibration on 2004 Explorer

[arj]

My 2004 Ford Explorer Flex Fuel 6 cyl full time 4wd (160,000 miles) has developed a vibration (rhythmic thump) when decelerating on a flat smooth road. It feels like when you drive over the spaces in concrete. No noise, just spaced vibrations. It seems to do this at speeds above about 30 mph when my foot is taken off the gas to slow down. It does not do it upon acceleration or when cruising. It continues to do it when shifted into neutral upon deceleration (not transmission?). I can feel the vibration in the seat and console (not in the steering wheel) so it feels like it is coming from the rear of the vehicle. I recently changed the oil in both front and rear gear boxes. I also recently put two new rear tires on (the front tires were still about 75% tread). Drive shaft and U-joints seem tight. Any ideas on what may cause this type of vibration?

 

[wmaxwell]

I have the same problem, 03 V6 with 95K. It just started recently and feels like the transmission is downshifting and back. Another site recommended checking the motor mounts, will do that this weekend.

 

[nilich00]

I am having the same problem with my 2002 explorer with 120k miles.

Did you guys ever find out what the problem was and if so, what was your solution?

Thanks

 

[wmaxwell]

I have replaced all 4 tires and full alignment, the vibration is gone. I did not have an issue with a tire but the front were noticeably worn compared to the rear, I don't know how this would impact any speed sensors. The other item found was the rear end was out of alignment and corrected (my son works for the tire shop and they gave me a copy of the alignment data before and after). The deceleration vibration is gone.

 

[explorer02rob]

ive had this issue three times, once it was out of balance tires and twice is was the brake rotors.