DIY(ish): Front driveshaft replacement and transfer case notes

[pachieh]

Hey everyone, it has taken me awhile to get this service fully done due to some extensive travel I was on. But, I thought it was important to get this post done so EVERYTHING related to replacing your front driveshaft and doing your transfer case fluid change was in one place. Why? Because if you are doing your driveshaft, you should do your transfer case fluid at the same time.

I never would have done either had I not been troubleshooting what felt like misfires under light-medium acceleration. It felt like stuttering or “popping” and was REALLY annoying and made it not fun to drive. Doing some research, I found Tony’s driveshaft upgrade and used Youtube a bunch to troubleshoot the condition of my front driveshaft.

I completed the transfer case fluid change today and the car drives normally again! So much nicer and I can carve the roads by my house again. I would HIGHLY recommend that anyone with over 50k miles look at doing both pieces here, transfer case fluid change at a minimum if your driveshaft is ok.

BMW will say the transfer case is a LIFETIME oil with no need to change. As you can see from the photo, that is DEFINITELY not the case. No oil is lifetime.

Time to change your front driveshaft: 90 minutes
Time to change your transfer case fluid: 45 minutes

Symptoms of a bad driveshaft: Rust on the u-joint, lots of play in the u-joint, perception of “misfires” under light-medium acceleration like something is popping.
Symptoms of needing to do your transfer case fluid: Perception of “misfires” under light-medium acceleration like something is popping and just good maintenance close to LEAST 50k miles.

A few notes:
• Yes, you CAN drive your car with no front driveshaft. Just keep in mind that if you use Rhino Ramps, it’ll be a MASSIVE pain to get back up on the ramps since you’ll only be RWD and the fronts won’t drive the ramps into the ground for grip.
• Pull fuse #63 under the glovebox to disable the transfer case. It’s a 30-amp fuse and green. Some will unplug the control computer on the transfer case under the car, but I could not get my hands onto the harness enough to do it because the transmission brace is in the way. Do this to see if your problems are related to the driveshaft or the transfer case.
• I only had full access to three of the four front driveshaft mounting bolts where it connects to the front diff flange when putting it back on. Again, things are tight down here. So, I used a marker to mark the bolts I had torqued down. Then, I drove the car for a minute and put it back on ramps; lo and behold the unmarked bolt was in the right position and I torqued it down.
• You need a Foxwell NT530 or ISTA+ to recalibrate the transfer case after the fluid change. Don’t do the transfer case unless you have either.

#63 fuse (VTG) removal info: https://fuse-box.info/bmw/bmw-x5-f15...uses-and-relay


I am not here to recreate great info others have done, so I have links to videos I used to help me get both of these done.

Tony’s Driveshaft (dentprotony on the forum here): https://f15.bimmerpost.com/forums/sh....php?t=1955558
Tony’s driveshaft removal/install on Youtube:

Notes:
• You MUST use a NLGI2 grease for the driveshaft splines.
• You can reuse the driveshaft boot over the splines, just don’t tear it. I used a pick to get mine off the old driveshaft. Recommend putting it on the new driveshaft BEFORE you install it…
• Use a wire brush to clean out the old grease from the female end of the spline input on the transfer case. It was impossible to get all of the old grease out, but your splines should be well defined and clean before you put the new driveshaft in.
• My splines on the transfer case were actually in pretty good condition. None of what others have seen for half of the splines being super worn down because of the small length of the splines on the driveshaft.
• Have an assortment of swivel socket adapters and extensions. Things are tight down here and you need any advantage you can get.
• There will be a LITTLE play after installation. Tony mentioned that heat expansion should make it go away, mine hasn’t though. I don’t feel it and I will assume everything is ok. Play for me is barely any up and down, none left and right.


Transfer Case Fluid DIY Youtube (credit to Eddie M Cars):

Notes:
• I used a 14mm ratcheting wrench with the 14mm hex adapter. If you don’t, it’ll take you FOREVER to get the fill plug out. There is no drain plug, hence the fluid extractor.
• Don’t expect to get a torque wrench in here. Just tighten and check after driving it that you aren’t leaking any oil.
• I took out ~560ml of oil and put in ~580ml before it started coming out.
• I will drive the car about 500mi and then do the fluid change and calibration again since I have 80k miles and this is the first time it’s ever been changed. Rather do this twice instead of rebuilding or buying a transfer case.



My original driveshaft play: https://www.youtube.com/shorts/XA9CH...DN6_OvooPnxYpu

Lastly, I will be sending my transfer case fluid off to Blackstone for analysis. Again, a few bucks here could save a truckload of $$$ down the road.

[Donniedarko]

Great share, I jsut got my driveshaft from Tony too : )