Driveline Refresh
 

Hey guys,

Hoping you can assist with my driveline refresh project.

My symptoms: noticeable slack in the driveline when going on/off throttle. "clink" sound when shifting into D or R at a stop. When you get under the truck and shift into D or R, you can see the driveshafts twisting.

At this point I am unsure if I have stripping "splines" as many do. I know it will likely make sense to rebuild the front driveshaft with the longer splines, my concern is installing it... what's the final word on installing the extended driveshaft? PITA?

Do you guys recommend rebuilding/replacing the rear driveshaft "while I'm in there"? It seems like most of the sudden failures come from the front driveshaft (splines stripping). If the rear is likely OK, do I just replace the guibo and be done?

Parts I want to order:
front guibo 26117503159 77.39
nuts for front 07129904473 .98
rear guibo 26117511454 50.90
nuts for rear 26127536563 1.66
center mount 26121229726 71.70
rear driveshaft cv seal 26111229078 8.51
rear driveshaft grease 07551225051 this isnt avail

http://www.realoem.com/bmw/diagrams/o/w/97.png

Do I need any more parts?
ie:
centering flange 26117507533
protection cap 26207503105

Anyone done this job recently? Please advise. Thank you!

How about transfer case chain slack? I would look there first. Search for this. I think there were members that were able to check the slack with the transfer case still on the car.

Yes, I will check for slack in the chain. I hope that is not the case but I might as well be prepared for it. There is a method to check with a screwdriver.

Yea thats it. Don't stress it, not that hard to do. Seen some DIYs.

Thanks Slick.

I have a source on a re-man TC for $1500. Totally gone through and good as new. I might go that route if I have the chain stretch, just to be sure.

Truck goes in the air this weekend/early next week!

Although for most of the people here the problem was caused by the front driveshaft in my case it was the rear. I think that's just $150 or so for that piece.
I had the same problem and I replaced the front first with long splines shaft (no luck), then the chain in TC (no difference again) and then the rear driveshaft joint. I think it's called constant velocity joint - 26117526822. I replaced the rubber donut joints as well but the old ones were as good.
So, just to get rid of the noise from D to R I would do the 26117526822 first. It's the cheapest, then the front drive shaft splines if the noise doesn't go away and then the chain in the TC... but that's based on my experience.

darks, while you're in there, i'd consider doing motor and or tranny mounts. they can allow a lot of flex in the driveline when worn out.

Thanks for your input. It's really not the noise that's bothering me, it's the slack. If I drive it, it's no issue, as I am more careful on and off the throttle. But if I mash the gas from a stop I will get a nice "clunk" which makes be believe my splines are stripping?

@dinane39

Trans mounts were done about 30k miles ago with the new transmission. Engine mounts may be original though, I didn't suspect the mounts to be bad, so I will look closer now, thanks.

I have rebuilt transfer cases before, but never on one of these. In general, it's VERY simple compared to a tranny or even a differential. First question...are the parts readily available for one of these cases? Seals, chain, ouput flanges, etc. (if that front flange gets damaged by the too short driveshaft)???

But I'd be 100% sure of the diagnosis before tearing into it. Or spending $1,500 for a rebuilt case. I'd also bet that anything other than the bearings is pretty costly if you're going to tear it down yourself, but still a good choice to DIY.

If the motor mounts were bad, you'd probably be feeling a constant vibration. Mine were totally shot, and I did not get any clunk. Also, on mine, the engine was sitting noticably low.

I do get a mild vibration at idle. I always figured it was part of the V8 experience. Maybe I should do them just to be safe. I'll look through my stack of receipts and see if they've been done before.

The question I am asking myself now is do I just drop a bunch of coin on driveline parts and get it done, or do I replace a single part at a time to try to isolate the problem.

My thought is that the truck has 140k miles, it's better to be safe and refresh the driveline regardless.

I'm getting ahead of myself, going to start by disassembling and analyze from there.

If your truck has 140K on it, I can guarantee the motor mounts are done. Im doing mine at 80K just to be safe. I believe that you will feel a significant difference when they're done. Good luck.

i am subscribed to this! about to do a very similar project as my driveline is loose as a mofo!

It can get VERY expensive to just start throwing parts at an X5 unless you're sure they are bad. A pair of motor mounts are about $225 for just the parts. On my car, the failed mounts caused the passenger side mounting bracket to get damaged, and that was a huge PITA to change. So it's not something to ignore. But they are oil filled, so take a close look at them and see if there's oil all around them. If you have near 100K miles, it's not all that unlikely they are bad.

Do keep in mind that when you pull the reinforcement plate to change the motor mounts, the bolts/nuts are one time use.

That is exactly the same simptoms i had. When my Indy told me that is caused by the rear drive shaft I thought I knew better because most of the people here did the front drive haft and the chain. So, I did as I mentioned earlier the front shaft thinking the same as you do and then the chain. I spent a few hundred on the shaft and a hundred on the chain and the final option was the rear drive shaft. The splines on the front shaft were worn out but the noise didn't go away after replacing the drive shaft and even later with a good transfer case with perfect splines and new chain. I put my money on the rear drive shaft.
You can check the front splines easily. It shouldn't take you more than 15-30 minutes. Unfortunately I don't know a way to test the rear driveshaft. Although I replaced the faulty component wasn't obvious it had a play. You need quite a bit of force to generate that clunk noise.

If you want to rebuild the TC you can find all the parts you need and it is very easy to do it while it's out. I used cobratransmission.com
The play you find can be combined from all the components in the drive line but in mine it went away by replacing the rear shaft. I also had play in the axels and getting new axels didn't do much...

Thank you. I'm going to start by inspecting the front splines. Do you have any ideas to test the rear shaft? Based on my research, the rear is not rebuildable, so just buy OEM if I want to replace?

Re: motor mounts. Truck wash under warranty til 100k so I thought they had been done at some point. Method to test if they are bad?

Yea park perpendicular against curb. Front wheels against curb. Put car in drive. Left foot on brake, hard. Right foot quick solid jab on throttle. Don't be afraid to really push it. Won't go anywhere as long as you on brakes. Do same in reverse. Have hood open and look at engine. It will come out significantly if it's the mounts. Mine went at 75k miles. Oh and they are $80 from Craig at Bloomfield BMW.

You should be able to test your whole driveline with this method. Just don't know who wants to lay under your car while you rev it.

Thanks!!!!! :thumbup:

Speaking of drivetrain clunk, one thing that CAN do this is a failed intermediate driveshaft bearing; if the rubber ring around it it totally shot.

I think one thing that would be highly useful at this point would be to get the car on a lift, and have a good independent BMW mechanic give it a total once over. If you start by replacing items that are visibly shot, you might solve your problem. And even if you don't, there's not much harm in replacing a component that is compromised...and you will narrow your search. With a lot of drivetrain issues, you can SEE the damage; ie a torn guibo. You can yank on and twist driveshafts and axles, and sometimes you'll feel play right off. The motor mounts are a bit tougher to get a close look at, but with a boroscope, you can get a great look at them from above, (and a good shop should have one of these cool tools.) Not to mention, a good BMW tech will probably be able to tell whether the motor mounts are bad just by looking at how the engine is sitting; it will often be at the wrong angle and too low.

Pay the shop for an hour's time for a full underbody inspection. Once you know the issues and associated costs, you can then decide what you want to tackle yourself vs. letting the shop handle.

I had a shop look at it a few weeks ago. They recommended new front and rear driveshafts.

Will check for visible issues first as someone mentioned. If I can solve the problem by replacing a few smaller parts then why not.

Well, that doesn't sound good. But there are a bunch of serviceable components in both driveshafts. Did the shop say what part of each driveshaft was bad? I would think the only bad components that could condemn the driveshafts would be the splines in the front shaft, (perhaps also requiring attention inside the TC), and the u-joint in the rear shaft.

Although if my rear driveshaft had a bad u-joint, I'd take the whole shaft to my local driveshaft shop. Even is there was no way to service the u-joint, perhaps they could cut the joint out, and weld in a serviceable u-joint;(then rebalance). Probably would be a small fraction of the cost of a new driveshaft.

I just don't get how a cars driveshaft should fail at ALL without either serious off-roading,(done that), or high HP drag strip use.

This is the part that failed, caused the clunking noise and had a good play on my rear drive shaft. It looks like the rear driveshaft connects directly in the rear differential but it has this constant velocity joint in between (part 17).

http://realoem.com/bmw/diagrams/u/a/193.png

http://www.bmwbuddy.com/prodimg.php?...um=26117526822

http://febest.org.ua/avto-zapchasti/...6117526822.jpg

So I got it on blocks and had a good look around.

The front shaft is super tight. No slop when shifting into D or R, and not able to twist it manually with the truck off.

The rear shaft guibo and center support bearing are completely shot. I'm sure the constant velocity joint is bad too. So the entire rear drive shaft is coming out tomorrow, front as well to inspect splines.

Did the engine mount test, no abnormal lifting or twisting of the engine. So those must have been done at some point.

More news tomorrow after my PB blaster goes to work tonight.

Thanks for all of the help.

Got the front shaft out today. The guibo looks a lot worse now that I have a good look at it. By the way, the splines appear to be completely stripped. I have no idea how they held on. The grease on the front driveshaft splines was still bright blue... Factory?

I've decided to start by replacing the front shaft, guibo and bolts. Hopefully this isolates my clunking issue.

On second look, the rear driveshaft slop that I was seeing is actually the rear axels/CV. The shaft itself still has a bright white sticker on it which makes me believe it simply cannot be original. I'm not sure how much slop is supposed to be present in the constant velocity joint.

Considering the rear shaft is a bear of a job compared to the front, plan is to start with the front and bolt it all back together. If there is still slop then we will go from there. Hope to order parts tomorrow and put it back together early next week.

So what's the condition of the internal splines of the output shaft in the TC that the driveshaft goes into? Hard to believe they are good if the splines of the driveshaft are completely stripped. If the inside is stripped, you can either get a driveshaft that has a bit longer splines, (thereby engaging the undamaged part of the internal splines in the output shaft), or replace the output shaft in the TC, or BOTH. But a stock shaft if the output shaft of the TC is already damaged will not last long.

Here's where you can get those parts:

BMW X5 Transfer Case Parts : Automatic, Standard Transmission and Transfer Case Rebuild Kits, Cobra Transmission Parts 1-800-293-1848

If you DO decide to replace the output shaft, I would certainly do all the bearings and seals in the transfer case, as it's got to come apart anyway. You can get a good look at the chain at that time, ($90 to replace). This site also has a video on dissasembly, it's really not that hard.

To be perfectly fair, I didn't look at the internal splines of the TC. From my research, I thought the shafts could strip and the TC splines be perfectly fine?

I will look at that tonight. I wanted to just buy a new front shaft and put that in, but it sounds like I run a risk stripping that one too.

I have this epic road trip planned for the X in mid-December... I'm starting to sweat now.

Thanks, Skyline.

Ok, here are some pics.

Shaft...
http://just.razzi.me/photos/858909/4b8f528.jpg
http://just.razzi.me/photos/858909/4b8f528.jpg

TC...
http://just.razzi.me/photos/858911/19b8856.jpg

So to me the front shaft looks striped when you compare it with this...

http://cobratransmission.com/images/...201%20Inch.JPG

And pics of the TC for reference...

http://cobratransmission.com/images/...ut%20Shaft.JPG

My driveshaft spines are not flat at the top, they are sharp and have some exposed metal (shiny part). The TC splines I am just not sure of... What are they supposed to look like?

I spoke with the PO via text. He said both shafts are original. He did remove them when he did the trans 2 years ago, but deemed them fine to use. He isn't the type to half ass it, either.

So my verdict is:
Replace front shaft, guibo, supporting parts

Unsure:
TC input striped?
TC chain

Ay help???? Thanks guys..... Couldn't do this project without help from the forum.

The root and the top of each spline should be more square cut, less sharp. They don't look stripped in your shots, that means the tooth is worn off completely. They do look very worn. A little hard to tell without comparing the length of the splines.

Replace both, IMO.

Check the chain before you take the case apart, to see how loose it is and whether it needs replacing at the same time.

Man, that is really a poor design. Guess I should be glad I have xDrive.

Well, clearly the shaft is badly worn. I think I'd go for the longer shaft from Cobra.

Tough call on the output shaft...it's not exactly inexpensive. And the longer driveshaft can make up for some damage. I think if I were you, I would clean it up as best you can, then try to take a little higher resolution photo. Talk to the people at Cobra, email the photo to them, and see what they think. If this car is going to be a long term keeper, it might be a good thing to do the output shaft and chain.

My guess is that it's kind of like a suspension problem. In a suspension, once a bushing or joint fails, the rest of the components take a beating from the slack caused by the failed components. If the bad part is not replaced promptly, others will fail soon. With the driveshafts, once one component fails, other parts are soon to follow. I'd bet in many cases, a failed Guibo starts the the chain of events, but so could a worn chain or bad CV joint. Anything rubber underneath the car is only going to last so long. I'm sure driving habits can be a big contributing factor as well.

And it may be that you haven't heard about these issues on X-drive cars because they are not old enough or have enough mileage.

The output shaft is $400, chain another $70, bearings and seals another $200. So MAYBE under $700 for everything.

OR I could have a rebuilt TC with warranty on my doorstep for $1450. Yeah, it's twice the cost, but it saves me a lot of time and headache and I know it's done right.

Add the front shaft and components... $700. Rear shaft and components... $700.

So almost $3k but I will have a perfect driveline.

F$%K

Do you have a pick of the guibo? Just curious to see what it looks like after this many miles.

I can try to snap one today, if not, next week.

Open up the TC case drain and fill plug, and test the chain for stretch. You might not need to do anything with it. I have a feeling you do though just because of the power this car has, and the mileage.

I assume at this point you have looked are some tutorials about pulling apart the transfer case. It really is NOT that hard. About the only special tools I needed for the last case I did, (a 242 for my Jeep), were retaining ring pliers, snap ring pliers, a blind bearing puller, (ended up buying three before I got one that worked right) and my shop press to press the bearings into the case. I used some big sockets to press the bearings in, so you will need something the right size to press them in.

If you want to increase your comfort level, you could also look at some videos from Extreme 4X4 online. They rebuild transfer cases all the time on their TV show, (usually to put in lower gears or a rear driveshaft slip yoke eliminator). For that $700 labor, it's really at MOST 2hrs of work to change the chain, output shaft and all the bearings and seals, even if you've never done it before. Really the only tricky part is making sure all the case bolts go back in the holes they came from....there are identical looking bolts in differing lengths.

As much as any warranty is nice to have, I'd say this transfer case is one of the more bullit proof components in the drivetrain of an X5, expecially freshly rebuilt. The one thing really likely to fail is that output shaft due to the improper engagement of the driveshaft...and I doubt they'd warranty that.

Yeah, I'm going to attempt it myself. Hope to have the TC off on Sat or Sun hopefully.

Thanks for the words of encouragement. This will definitely be a test of my skills.

Just examine everything once it's apart. If there's any damage to other components, and the parts bill runs too high, there's always the option of bolting it back together, and getting the rebuilt TC. Good luck and let us know how it goes.

Also, you implied it was going to be $700 for your rear driveshaft. I thought just your intermediate driveshaft bearing was bad?

Yeah, I'm debating doing both shafts "while I'm in there". As you know that phrase can be dangerously expensive. Assuming the TC needs to come off then I will certainly pull the rear shaft and do the guibo/CSB and determine if I want to replace the entire shaft. Somehow the complete rear shaft, rebuilt, is $438. The front shaft is closer to $600 and is shorter and far less complex. Figure that out...

Front guibo
http://just.razzi.me/photos/863934/4b8f528.jpg

Infuriating to think this $100 part failing could cause a chain reaction to eventually rebuilding the TC. Hard to say if that is the case.

Guibo is rock hard, brittle, cracked.

How many miles are on the car again? Better yet, at what miliage did you start noticing the issue?

142,000

I purchased the car with 140k. When I bought it, I knew this was the final weak link. After this is done, the truck should run for a long time.

Exhaust coming out now. One bolt being a bitch due to location (pass side rear after the resonator). Had to drop the muffler in back to get access to it.

That Guibo is certainly done; but I've seen much worse. When they are really bad, they sometimes come off in pieces.

$100 part, might be worth just doing before 100k, maybe preventative maintenance? Thoughts?

Without question.

Exhaust took about 75 minutes to do.

http://just.razzi.me/photos/863993/4b8f528.jpg

TC out!!!!!!!! 5 hours later.

http://just.razzi.me/photos/864103/4b8f528.jpg

Doing good. 5 hours to drop TC?

I guess the first time always takes forever... I've been there.

Yeah, 5 hours. Exhaust took over and hour of that. As you can see I ended up pulling one of the mufflers... Without taking the bumper off.

As with many jobs, you end up spending a lot of time on a couple of small snags. First was one of the exhaust bolts. Next was figuring out how to separate the drivehaft. Last was getting the last TC bolt.

Massive parts order on Monday and hopefully back together this coming weekend. I trust the installation will go quick, 2 hours.

Oh 5 hour total. Yea I know what it's like to get snagged on a part. Not questioning your speed. Just want to know what snagged you. More importantly how you got around the snag.

Boy, can I feel your pain. More than once, BMW exhaust bolts/nuts have kicked my ass. But as time went on, my arsenal of tools for cutting them off grew, and my pain was lessened. The connections between the exaust manifolds and the cats always seem to be the worst. One thing that's on my shopping list is one of these:

MT1872L 6" EXTENDED LENGTH CUT OFF TOOL

There are other versions of these out there, and some may be less costly. But this is a great tool to have when you need to cut off those impossible to reach exhaust bolts.

I go the sawzal route. I'm like a surgeon with it these days.

That's funny. A sawzall is great if you can get it in the right position. I once bought an entire front clip from a 5 series..all the way to the B billar, and had it delivered by the wrecking yard. I took off the parts I needed, and wondered what to do with the rest, as I had no way to get the remaining parts to a salvage yard. Out came the sawzall, and in about an hour, it was down to pieces small enough for my recycle bin. I got a LOT of grumbles from my trash collecters that week when they saw me put almost 1/2 a car in the trash. But they are pretty used to my antics at this point.

Ha, out here, I can probably put half a car on the sidewalk, not in pieces, and some scrapper will take it within a half hour. lol.

And yes, I had a scrap, 318 e30, that I got for parts. I cut it into 3pc when I finished.

You guys are giving me WAY too many ideas....

Got some parts ordered...

Ordered from Midwest Transmission:
Rear driveshaft rebuilt - $432 all in (includes CSB and CVJ)

Ordered from Cobra Transmissions:
Longer front driveshaft
TC chain
TC output shaft
TC seal kit - $1139 all in

Last order will come from BMW:
front and rear guibos
bolts/nuts
grease
TC fluid
WHAT ELSE ???????

I love my truck. I love my truck. I love my truck. RIGHT ???? :D

lol. not the end of the world. Look at it this way. Those parts lasted that long, so now you can sleep easy, knowing they will last that long again.

Exhaust gaskets.
Did you order nuts/bolts for the reinforcement plate?
Front Sway bar bushings since you have them unbolted already?
Oil to change the front diff fluid since you have the reinforcement plate out already?

Very good advice here. I suggest you spend a bit more $$$ epdarks

Exhaust is Dinan. Not sure if gaskets are same as OE? Need to research.
Sway bars are Eibach, bars/bushings new in last 30k miles, visual inspection shows no issues.
Good point on the front diff, I will ask the PO if he ever changed it.

Thanks for the input.

Question for you guys...

Why is it important to "line up" the shafts after removal? Since I am putting in new shafts both front and rear, wondering how I do this?

Thanks.

Hey darks,
Just a guess, but, I think the drive shafts are "balanced" from factory. This applies to re-installation of the the old shafts (mainly the two rear drive shafts).I always make an alignment mark on mine if I have to remove them. Unless the splines are keyed, you may want to take the new ones to a shop to get them balanced if it hasn't already been done by your parts/rebuild source. I say do it right since your putting the effort forward. It might be overkill, and others can comment. Its a small radius, rotating mass, but if its off by alot, could drive ya nuts with vibration and all and work against all the fine work your doing.

Well I did confirm that my rear shaft will be fully balanced.

Front shaft is coming from Cobra so I'm assuming that one is balanced too.

I did mark the old shafts and the TC and front and rear diffs. Those marks so me no good with new shafts, right?

As long as I'm not getting vibration then I can assume all is well?

Right X3.

Is the rear shaft coming with the intermediate bearing installed? If not, and you pull it apart to install the bearing, make sure you scribe the spline connection so it goes together exactly in the same orientation as when you split it, (to maintain the correct balance). I've screwed this up on a repair many years ago, and it did not seem to matter, (no vibrations), but it's supposed to be balanced as a unit, (I marked it with a magic marker...and accidentally wiped my marking off before reassembly).

So I am thinking about reassembly. I want to make sure I don't fuck this up.

Do I need to worry about resetting anything, computer wise?
Is there a break in procedure for a new TC?
Anything else I should worry about?

You don't need to reset anything for the per facelift model. Just put it together and let us know.

Hopefully this is the last question I have to ask you guys.

Received my package from Cobra in 3 days... Nice! But, my output shaft has a nice sized nick in it, right on the bearing. Is this ok or should I do an exchange? Due to shipping, exchanging it would mean my truck is down another week... Extremely frustrating considering all of the remaining parts are here and ready to be installed.

Pic...
http://just.razzi.me/photos/870398/4b8f528.jpg

Dude call Cobra and ask them if this would be an issue. Tell them that you are paying mechanics to put this in. You do not want to pay them to do the work twice. If they say they will replace, ask for expedited shipping.

What does that nick come in contact with once assembled?

I spoke with Omar at Cobra. He asked to send him a picture, which I did just now. He said if it is defective then he will send me a new part right away and include a box and shipping label for returning the old one. He apologized for any inconvienience, and insisted it must have been damaged in shipping. With the way they were wrapped in bubble tape, I don't see how that is possible. In my opinion he sent me a bad part.

Either way, the truck is down for another week....

Life goes on. Maybe I can get those new LED tails installed this weekend.

Call them back and ask them to expedite shipping. Tell them your shop is making you pay storage.

Just an fyi, I believe Cobra does have a, Xoutpost account.

That is good. Maybe if they check the threads, they will know their rep is being discussed. No matter how you slice it, a damaged part was sent. It is not OPs fault to wait another week for another part.

I got an email from Cobra about 15 minutes after I sent the pic. It appears that they are sending me a new output shaft at no cost to me including shipping both ways.

Things happen, I feel that they went above and beyond to make it whole, and at a significant cost to them.

Thanks Cobra.

Nice, nice. I love it when a good company has good service.

TC is open! The chain is not nearly as loose as this guys': TC Removal Pictures

In fact the TC is slightly different than his. There is no "pad" at the end. Everything on the inside is perfect. Of course I am replacing the output shaft, but also the chain/seals.

My buddy is a tech at Range Rover (see that white one?)... he is doing the work for me. It pays to have good friends!

Forgot the pic !!!

http://just.razzi.me/photos/879875/4b8f528.jpg

Good to hear! Sounds like Cobra Transmission may be the only place that sells parts for these things and they seem like a very stand up company. their was enough information on their website that I knew exactly what my problem was and what I needed to purchase. (Pickedu p the chain for $75 on black Friday) Not to mention fast shipping!

To be completely honest the 2nd output shaft is hacked up as well. Right on the "journals", just like the last one. My guy says it will be fine, but I'm questioning the QC down at Cobra.

After 4 weeks of not driving the X, my plan is to re-install everything tonight.

Got the TC back from my Range Rover buddy... everything bolted in no problem.

Rebuilt rear shaft looks NEW... very impressed for $430. Still not sure if it was really "needed", but too late now.

Missing my X like crazy. My GF is pissed because I take her car everywhere. Wish me luck tonight!!!

Good luck. Let us know how it goes.

I made it 10 minutes until I realized I could not get the "cap" that covers the front driveshaft splines onto the new shaft. I'll need to press it on somehow. I didn't order a new one (idiot) so now I am waiting another 2 days to get it from my local stealer ($27).

It's always one measly part that stops the entire process.

Life goes on. I am rebuilding the 3rd floor of my house right now. Before the X was down I had some 14 foot 2x10s sticking out the back.

http://just.razzi.me/photos/898384/4b8f528.jpg

Somehow it took almost 10 hours to bolt everything back in. Struggled with a bunch of random stuff, but eventually prevailed! Truck is on the ground, running... BUT...

I now have the "trifecta" after the truck sat dead for a while. Anyone know a sure way to try to clear it? Tried unplugging the batt for 10 mins, no luck.

I don't see how anything could have changed. Hopefully the truck is just spooked. My front right brake is applied for some reason. Only the front right. That would make me think.. Speed or ABS sensor? Was also told... Steering wheel sensor?

I guess I will have to drive the beater one more day. Sigh.

What do you mean by trifecta? Do you have access to dis or inpa?

ABS, brake, and stability control lights.

I don't know what those are so I guess not.

Dis or inpa is BMW software to diagnose problems. I suggest you take a short drive. Car may have just freaked out from being in air so long.

Thanks Slick. You've been a big help throughout this thread. Props...

Going to get the garage cleaned and take it around the block. Fingers crossed.

About 2 minutes into my drive... All lights off!!!

Noticeable increase in driveline response, and noise from driveline reduced in some situations. Car no longer "clinks" when engaging R or D with brakes on.

The shifts are better as well. Most likely the TC chain slack.

To be fair I haven't put in truck through its paces yet. Something I have been reluctant to do since I started diagnosing these issues for fear of TC failure and standing my GF.

Yes I let the GF drive the X only after she got proper instructing on the vehicle.

BIG thanks to X Outpost.

Here are the parts I ended up needing...
Front shaft rebuilt with longer splines (Cobra
Rear shaft rebuilt locally (Midwest Transmission)
TC chain, input shaft, seals and bearings. (Cobra)

From BMW/Tischer/ECS/etc
F/R guibos with all associated nuts, washer and bolts.
Grease for shafts (black lithium)
White lithium grease for shaft ends
1 qt TC fluid (super easy to fill while TC is on the ground)
Protection cap (fucked up my previous one on removal)

4 huge jack stands
Multiple jacks
Tq wrench
A good friend to lend a set of hands. Or in my case, I handed him beer and he did the grunt work. Sometimes we worked together on things.

Can't wait to go get some miles on it.

Give it a hundred miles, and slowly start enjoying it. You deserve it after all this.

Thanks, poor truck was down almost 5 weeks. If you really planned it right, I think it could be a weekend or 2. Just too many other things going on that required time and attention.

Just took it for a longer drive. Truck is an absolute monster in the snow. Driveline feels new. Truck is completely dialed in. Now to just keep it out of the salt.

What do you guys think of putting two front guibos in to extend the drive back into the transfer case.

Did you end up trying this? I was thinking the same thing.

No I didn't,
I replaced the front drive shaft with the Ext shaft from Cobra Transmissions.
I was concerned about the extra tension on the joint with the two discs.
The guys a Cobra were amazing and it was delivered to Australia within 3 days with the DHL $77 option. It was a little hard to install being that it's longer. It misses by about 2mm, but a little stretching of the engine/gearbox mounts and pop in it goes.
Would love to hear how you go if you try the dual discs.

Replace the Guibos first, chances are that is your problem. Do not start with transfer case chain slack. Guibos are the cheapest fix, do those first and see if the problem persists.

I'm going to climb under there this weekend and inspect, I'm getting a hum and starting to get a drivetrain vibration. At my mileage I'm assuming the guibo's are done and the vibration is the center bearing going out, or maybe the rear CV?

Yes, I'd rather not introduce more flex into the system with a second disc. I'm thinking I'll get my friend who works at a machine shop to make a solid aluminum disc for me and I'll buy some longer grade 8.8 or grade 10 bolts.

The flex has certain torsional characteristics designed to work with the stock driveshaft over the range of rotational speeds the driveshaft sees. Do not put two flex couplings in it.

That's why i was thinking an aluminum spacer instead...