Rear Pumpkin - Fluid Adapatation - THUMP
 

I know this is NOT the answer but coined the title as such

I don't drive the X much as it's the wife's.
I did notice one thing this weekend that I need to spend some more seat time with

Recently dropped the diff, new rear gasket seal (leak), new output seal.
Life is good. No more stained garage floor.

I felt a minor kick every now or then which was not there pre diff drop.
I know it's not a fluid issue and I have used the same gear oil in the same diff for at least 2 other diff fluid changes.

Just typing this out for the veterans to point out any obvious gotcha's.

Are you saying you feel a thump from the back when driving? Example: under power constant speed, almost like power is cut from the engine for 1/4 sec when you hit an expansion joint? Mine does that it's the rear subframe mount: my theory: when the weight unloads from the road dip, it effectively "slacks" the drivetrain. When slack is removed on landing, drivetrain whip.


Sent from my iPhone using Tapatalk Pro

Can't reply in certainty, but it was either from 1-2 or 2-1.
I was driving the X back from Labor Day and we were all exhausted. BUT, it was definitely noticeable to a point, that I knew I had to swap cars one day soon to isolate it further. Said kick was definitely not present pre-diff-reseal though.

Going to have to figure out a week where I can swap cars. It was a straightforward R&R but something is off. Only got to drive it 2 times this weekend with very little seat time. From a standstill, depending on how the pedal is engaged, there is a slight unpredicatness from 1-2. As in a surge if one throttles the pedal

In backing in the garage, I don't notice a shake - but if I do a hard reverse/brake, when it's loaded, there is a shimmy. Going to have to see how often I can reproduce this. I would say in the last 4 months, LCA, tension and BJ all in the front has been changed. The KEY point though is I don't believe any of what is being described leading up to when I dropped the rear

Did you disconnect battery when working on diff? Do you have a scanner that can read the TCM ? Could always have a coincidence situation. Maybe you just need to reset adaptations, sorry if I missed a mention that was tried, I'm following a lot of threads. Including the ones directly affecting my two x5s