2008 X5 4.8L Front Drive Shaft question

[Davidf]

I did not study the connection at between the driveshaft and transfer case, but it looked odd. My thought is that the connection is some sort of constant velocity joint and not a simple slip spline connection. A bit of service manual studying my give you some insight.

Update: After reading a bit more on the subject, it seems that the connection is indeed a splined fitting. So, we are all subject to the issue. I don't really notice a vibration, but it is my wife's vehicle and I don't drive it all that much. I am subscribed now and will be interested to see where all this leads.

[WMG/BMW]

I had the same sound with my front end (loud howling) was thinking it was something to do with the front diff but after my (indy) checked it for sure needed a stethoscope to detect but it is the passenger side front wheel bearing and the left has a slight sound as well will be replacing both front wheel bearing shortly. Also found slight leak in the water pump for a 4.8i 2008 (102k). My Indy will charge 1400 for everything, I will change the thermostat as well since the fluid will be dumped.

[Westlotorn]

Thanks for the reply. Funny, I ordered one front and one rear bearing just yesterday to try and find my issue. Still not sure about the Driveline. That loose splined connection just does not seem right to me. Hard to balance a driveline that can wobble.
I drove this car today again searching for answers. My wife drives it most the time. I drove 70 on the freeway for several miles then pulled off and checked the temperature at all 4 wheel hubs looking for a hot bearing causing additional hub heat. No luck they were all the same temp.
I am leaning towards the driveline as the cause but hate to change it and not be sure. My noise is still not loud but seems to be getting louder in a short amount of miles so I am sure I will know what it is soon.

[Westlotorn]

You can look at page 8 of attached thread and see what I found out. I wish I could do a quick cut and paste to add the info on this page.
Pictures are included showing the driveline changes from 2008 to 2010.
My front driveline was the source of my issues with the noise and slight vibration.
The front driveshaft was starting to fail, the U Joint at the front differential connection ended up being my problem but you could not feel it till it was removed, I think the splined connection at the transfer case connection was not an issue.
After removal the front U Joint was rough when rotated. Tight but rough. These should move very smoothly. The loose splines at the transfer case did not appear to have been causing any issue. I don't like this but the splines appear to work while loose. I chose to install the newer 2010 and up (improved) replacement shaft in my 2008 which involves some adaption, the bolt on front flange is not the same on the different years.
The newer shaft is similar but I think it may work better over time. Part numbers and cost are reported in the attachment. It is factory in the late model X5's which have more power than mine so I hope it works out. If it goes another 100,000 miles I certainly won't have any concerns.
Changing this driveline is not for the faint of heart. I would plan on 4 hours. It has to be jiggled into one exact correct spot and it will come out. It takes quite a while to determine the exact spot.
It goes back in nearly as hard. You just have to be patient and work with it. For me it took about an hour and a half to get it out and about 45 minutes to install the new one. Not counting re installing the shields and getting the car back down on the ground.

https://xoutpost.com/bmw-sav-forums/...cussion-8.html