Issue Shaking Slowing Down/Coasting on f15 50i

[Treezy]

Hey everyone I have a 2014 X5 50i xDrive that I’ve been having some issues with(shocker). I’ve owned the car for a little over 18 months now, and it’s sitting around 64k miles.

Right now I am having issues with the car doing a shuttering/shaking movement in the front of the car while slowing down. The issue first appeared after swapping into my summer OEM staggered wheels w PSS from my winter set up (OEM 19” wheels w blizzaks). There was a slight shuttering when slowing down, almost like every other tire rotation was making a shake. It would be way less obvious when breaking or accelerating, but was apparent at all speeds. When shifting the car to neutral the issue goes away completely, making me think originally (and the bmw dealer) that it was an issue with the diff. It was pretty minor and just an inconvenience, and working 7 days a week so I haven’t been able to take it to the shop for my 1.5 mile commute. Recently I’ve decided to do something about it, as it’s starting to get worse.

I brought the car into a local shop for some diag. They noticed when breaking hard at low speeds the front wheels spun backwards slightly. Nothing was visibly out of placed are messed up in the suspension. They swapped the front wheels (switched places LtoR and RtoL) for me and I noticed a slight improvement, which got worse after a week.

Took the car to bmw dealer. They were kinda stumped as well. First diagnosed with bad front and rear control arm. Replaced under aftermarket warranty. Issue still there. Just replaced rear air bags and front diff (and leaking head gasket) under warranty. Issue is still showing. Now the dealer is thinking this could be an issue with the transfer case, which might be covered by the warranty. Curious if anyone else had anything like this happen, and could potentially help with some diagnosis or ideas bc I’ve been in for this same issue now 5 times and over $10k has been spent on the car (fortunately not from me). I’m concerned they will deny this claim and I’m curious if anyone has any other ideas for what could be causing this issue, bc I’d prefer not to have to spend $5k+ out of pocket to fix that if it’s a “maybe it might” fix the issue.

Obviously if it’s free I’ll do it for shits and gigs but I’m starting to think they have no idea what’s wrong with the car. Any thoughts would be super helpful. Thanks!

[Djhumvee]

I'm pretty sure people here are going to suggest replacing the t-case oil and recalibration with a scan tool

[dentprotony@gmail.com]

Before you do anything maybe try removing front driveshaft, see if this changes anything, many of my customers experience shaking/noise/vibrations under load or braking, maybe try something this simple before going in with a tcase replacement

[tfunk88]

First thing I’d do I have transfer case oil changed AND the transfer case recalibrated. I’m guessing switching your tires got the transfer case clutches out of their optimum adjustment.

You can do the TC calibration yourself with a good diagnostic tool like a Foxwell NT530

[_ObiJon]

As everyone else stated, most likely a TC drain/refill and recalibration. I had the same issue and that solved it for me.

You can unplug the TC to assist in the diagnoses. Once unplugged, try to reproduce the issue. If it went away, proceed with TC service. And just to confirm, the recalibration is the most important part.

I bought ProTool (master license) and a Thor adaptor and did everything myself. Hardest part was finding/making a u-shaped tube to extract/fill the TC.