X35d Transmission Saga (Full Replacement)

[crystalworks]

Figured I'd post this since these things are getting up there in mileage. Some of this might be useful to someone in the future. And any input for those who have done this or similar work is always welcome. Not sure how many would be "adventurous" enough (read: cheap enough) to undertake this on their own. This is not a DIY, more of a chronicling. I have not done this before on an X5d, and so far, this has taken place over about 3 weekends.

First, the backstory. On the highway trans would slip out of gear reporting 4f85 and/or 4f89 for 3-4 gear ratio monitoring. Happened 3 times in a 6 month period, every time when cruising in 6th and requesting a gear drop for a pass. Pull over, restart, and can drive away. But the last time was the last straw as this was the wife's ride and I don't want her to feel unsafe. Took it off the road February 2020.

During 2020 I threw a hail mary (or 4) and had the valve body rebuilt and serviced the trans with seals/pan/multiple fluid flushes. Below are some shots of that, including the original fluid @ 166,000 miles.







Threw the rebuilt VB in and had the same results. I was taking a path of least resistance approach so I was not overly surprised or disappointed that the VB and trans service did not work. The company who rebuilt it for me warned me it was likely the E clutch bearing/bushing that had failed inside the trans with those codes presenting. Figured if I needed a "new" trans I'd throw the rebuilt VB in anyway as it would be good preventative maintenance on the younger unit.

BTW, I tried 4 fluids, Pentosin, Liqui Moly, Redline, and Valvoline Maxlife.. Only one that would get the transmission back into 4th gear was Valvoline Maxlife Multivehicle ATF. Uncoincidentally, it's also the thickest of the fluids. The gear change was not smooth though and after 4 or 5 changes would eventually trans failsafe.

So I left it parked and we drove our other Bimmers, fast forward to 12/2020 and I scored a suitable 88000 mile (verified) trans off of Ebay. $800 shipped. Not the prettiest thing in the world, but it should do nicely.



03/08/2021 Work begins. Spent about 10 hours on it the first weekend with a buddy. Was unprepared for how much extra work the diesel model brings with it. Made some good progress and then hit a major blockage. But it was 1:30AM at time of blockage so I called it for the day. So far:

• Unhooked all the NOX sensors and sensors for the exhaust.
• Dropped & removed exhaust
• Removed all heat shields and splash shields
• Unhooked and freed up sensors/cables attached to Xfer case and trans
• Removed rear driveshaft at Xfer case (suspended under truck)
• Removed front driveshaft at Xfer case and front diff
• Drained trans fluid
• Freed up DPF (this things sucks and is the current blockage as there was now clearance to get it out)
• Contemplated life choices

So we stopped when we realized the access panel for the flywheel bolts is blocked by the DPF. The BMW TIS procedure is laughable when they mention "setting the DPF to the side." There is literally ZERO room to access the 10mm bolt holding the access panel in. And even if you could get it out (we broke it loose) you would have no access to your flywheel bolts. It was at this point I realized this was going to be A LOT of work. And that I never wanted to do it again. So, the preventative maintenance ordering began. Ordered, exhaust gaskets, engine mounts, rear main seal, transfer case mount, all vacuum lines, pressure converters, and a new fuel filter.

03/22/2021 Work continues. Some notes and accomplishments.

• DPF removal is 100% a must to access the flywheel bolts. TIS is laughable: "Loosen DPF V-band and push to the side to remove access panel on engine to access flywheel bolts." BS!
• Engine mount must be removed to facilitate DPF removal (2 T12? bolts and 18mm engine mount nut securing engine to mount)
• Engine must be lifted AND subframe lowered to facilitate DPF removal
• An alignment will be necessary after job completion
• Right side engine mount arm must be removed from engine (4 16mm bolts I believe)
• Lower EGR cooler must be removed from DPF to allow enough room for removal
• 100% (or felt like it) of the cooling system will drain upon removal of lower EGR cooler
• There are 3 sensors (hope they're keyed ) and 2 vaccum lines total between the EGR cooler and the DPF that must be disconnected for removal. Multiple wire brackets/clips as well.
• Right side filter housing and engine partition must be removed to gain access to be able to remove wire harnesses and reach in to engine bay.
• The rear non-structural bar of the subframe (where motor mount vacuum lines run) should have been a bolt on instead of weld on job by BMW. It is CONSTANTLY in the way of everything happening. If I had a welder and knew how... I'd cut it out and put back in after job completion.
• Remove the transfer case actuator motor to give you enough room to pull back when removing trans (only an issue on diesels, of course, because the passive DEF tank is located there)
• You do not need a special tool to turn the engine while removing/installing flywheel bolts. A T12 (I think was the size) works fine on one of the dampener bolts. Just make sure you have it seated well before turning the engine.
• You will however need a special tool to hold the crank while you torque the flywheel bolts. Just ordered and received mine from TuneMyEuro.com the other day
• Make sure your starter is not frozen/locked in your trans housing like mine was. Hope I didn't damage the teeth or something. Did quite a bit of prying to separate the engine/trans before realizing the starter was not letting the top come loose. The bolts were out, but the starter stayed put.

A trans jack would be very helpful, I am buying one before putting the new trans in. We got it out with a floor jack and long adjustable cross support bar that we strapped the trans to. But that was less than ideal, multiple instances of us having to bench press the trans and/or Xfer case. They're heavy.

I'm sure I'm forgetting stuff, but I'll add it as I remember. I blocked it out from my head and took Sunday off mentally. Didn't even clean up the tools/area. Will do that this week in prep for swapping over the transfer case and mechatronics unit.

Here are some pics of the progress.

Smurf massacre. So. Much. Blue.





See that crossbar in the foreground? That thing can rot in hell!





04/17/2021 Work continues. We spent all of Saturday on it. A good 16 hours... I know, I know, we're working slow as molasses creeps. Well, we're doing it all on our backs, and there's a bunch of "while we're in there" going on too. So that's my excuse. I'm slow, I've made peace with it. Had to make a couple of tool and fluid runs too, so time management could have been better.

• R&R'd flywheel
• Installed new rear main seal
• Replaced worn (completely torn) transfer case mount
• Swapped Xfer case from old trans to new transmission.
• Installed new rear driveshaft flex disk/guibo
• Installed new transmission into the X5 (making sure the converter aligns with the flywheel, AND stays engaged with the pump is fun on your back )
• Installed starter onto trans bell housing

Some pics:



I think that mount is supposed to be attached in there?



I was in a hurry when I bought this mount so ended up getting a "Power Torque" mount from O'Reillys. LoL, I have no experience with Power Torque so went ahead and dumped a bunch of gasket maker into it just for good "feels." No matter how bad the pookie filled Power Torque bushing is, it's better than the torn one that was in there.



The bearing press tool I bought at Harbor Freight didn't have the exact right cup size for the bushing so a roll of Gorilla Tape filled in nicely. Worked like a charm and took about 10 seconds to install.



Old transmission after pulling the mechatronics/valve body out.



Here's a shot of the back of the motor after pulling the flywheel and old RMS. Took the shot for the info on the back of the block for S's and G's as I don't ever plan on being able to see that sticker so clearly again.

Now that everything is "installation is the reverse of removal" hopefully things will go a little quicker. Going to loosen the steering rack and really drop the subframe this time though so that the DPF and engine mount arm goes in easier. It was not fun wiggling those out.

04/23/2021 Got my DPF back from being cleaned by a diesel truck outfit in Austin. One day turnaround. They said it's one of the cleanest ones they've ever seen regardless of mileage and that the truck must be a well taken care of example. This x5 is at 166,000 miles and 30,000+ under our ownership. Told him previous owner was a dealer who would drive it between Texas and Louisiana so my guess is that the regenerations have always been regular as we don't do any regular short trips in it either. He agreed that sounded right.

Usually DPFs are flow tested but for the Euro ones they get they aren't setup for air flow testing so instead weigh each unit before and after. They usually do commercial semis and fleets as you can imagine. Actually took me 5 calls before I could find someone to clean this thing. Sheet says they pulled out 56g of soot/ash. More importantly for me as this was done as preventative maintenance is that the DPF got a clean bill of health and will not EVER need to come out again in my ownership. At $400+tax this is cheap compared to a new $2400+tax unit. The honeycomb element was visibly cleaner which is nice too.





I had to separate the SCR injection tube from the DPF flex pipe and all the sensors before giving the DPF over for cleaning. Posting this picture to show that we had bent the 2 EGT sensors up a bit during the removal process. I ohmed them and both are similar at ~14.6K ohms so I bent them back carefully/slowly and ohmed them again. Still reading where they were before and both are close so hopefully I didn't bork those up. @ $65/ea it would just add to the cost... which I will tally up fully later.

That brings us up to current. Hoping to get a lot done on it this weekend but our plumbing decided to act up so I might be running a camera and auger in the sewer lines instead. It's always something.

[liam821]

Wow, our X5 is creeping up towards your mileage, that doesn't look like a fun job at all and will not be looking forward to doing that. Nicely done with the blogging of your adventures.

[JDAURIA]

Well done! This is a pretty invasive job

Do you think not having the trans previously serviced (original fluid166k) may have caused this failure?

[RL18]

Wow! Nice work! I can't imagine putting the dpf back in after all that work you did but to each their own. Great to see someone not messing around and just "doing it" while your in there too

[crystalworks]

Originally Posted by liam821

Wow, our X5 is creeping up towards your mileage, that doesn't look like a fun job at all and will not be looking forward to doing that. Nicely done with the blogging of your adventures.

Hopefully you have serviced your trans fluid/filter/seals so you don't have to experience the "joy" of this job.

Originally Posted by JDNY516

Well done! This is a pretty invasive job

Do you think not having the trans previously serviced (original fluid166k) may have caused this failure?

Thanks. I 100%, well 95%, believe not servicing the transmission leads to these types of failures. ZF recommends fluid changes at 60-80k miles for these transmissions. BMW (and other manufacturers) don't care what happens to the vehicle after 100k miles. One of the reasons they do this is to bring down cost of ownership data (think JD Power and Consumer Reports), they state lifetime fluid as trans service is an expensive maintenance item at a dealership or independent. As a result, I see and read about all kinds of BMWs with ZF transmissions in them having shifting problems or needing replacement. See it on CL all the time.

Originally Posted by RL18

Wow! Nice work! I can't imagine putting the dpf back in after all that work you did but to each their own. Great to see someone not messing around and just "doing it" while your in there too

Thank you, definitely a ton of work. Yeah, I looked at deleting and the cheapest I could get it down to with questionable Chinese Ebay parts and a reasonable tune was $2000+. And I'm not big on a luxurious European SUV smelling like a 90's diesel pickup. Just personal preference. Don't blame people for deleting, just not for us.

With jobs like this I tend to do as much preventative maintenance as possible. I don't want to be back under the truck touching things I've already touched if I can avoid it. It drives up the cost of making repairs a bit but I find it greatly improves the reliability of my Bimmers. Worth the peace of mind IMO.

[RL18]

Originally Posted by crystalworks

Thank you, definitely a ton of work. Yeah, I looked at deleting and the cheapest I could get it down to with questionable Chinese Ebay parts and a reasonable tune was $2000+. And I'm not big on a luxurious European SUV smelling like a 90's diesel pickup. Just personal preference. Don't blame people for deleting, just not for us.

With jobs like this I tend to do as much preventative maintenance as possible. I don't want to be back under the truck touching things I've already touched if I can avoid it. It drives up the cost of making repairs a bit but I find it greatly improves the reliability of my Bimmers. Worth the peace of mind IMO.

That sounds about right for pricing. I completely get it though. It seems like you understand how it needs to be driven and taken care of to keep it happy with the emissions equipment intact. If It ain't broke don't fix it.
Me on the other hand can't help myself and since one of my first vehicles was a 7.3L super duty, I don't mind the diesel smell at all. The ammonia smell though, that gets to me lol.

[crystalworks]

Trudging along here all. Got a couple of hours work on it Tuesday. I got the flywheel bolts torqued up. Also got the DPF back in the truck and loosely mounted (still have to install engine arm and mount so need play). That was a big accomplishment. Much easier than getting it out. I unbolted the steering rack and let it hover so I was able to lower the subframe another inch or so. That made a HUGE difference and gave me necessary clearance. Needed to employ the wife for a minute or two on the 4' pry bar while I maneuvered the DPF in. But was much easier going in than coming out.

04/04/2021

Some notes:

• Crank holder/turning tool requires the removal of the fan shroud for clearance.
• Be sure to loosely install each flywheel bolt before torquing. I had to re-loosen 3 of them when the 4th (of course) would not quite line up with the torque converter.
• Easy to locktite and torque the flywheel bolts to 42ft lbs using the crank tool. Without it I was turning the motor before reaching torque spec.
• Unbolt the 4 nuts/bolts on the steering rack to allow the subframe more droop. Provides much needed clearance for the DPF filter to be reinstalled.
• Getting the 2 vacuum lines on the DPF SUCKS. I should have sprayed the nipples with soapy water before installing, but then they would have been slippery... so. Wanted to order new lines for those but they were on back order.

You can see one of the flywheel bolts through the access panel.



A couple of shots of the new RHS motor mount versus a new mount. Had not completely failed, but definitely had some droop to it.



Going to put another couple of hours into it today so look for an update in the next few days. Can't wait to get this thing back on its motor mounts and the subframe back in so I can move the engine hoist and jacks out of the way.

[WesleySnipes]

Looks like a heap of work! Good stuff.

[blue dragon]

This thread made me realize Crystal Works is a masochist . No way I would undertake this without a lift.

[crystalworks]

Originally Posted by blue dragon

This thread made me realize Crystal Works is a masochist . No way I would undertake this without a lift.

Oh, I told the wife (and she agreed) that the next house we get has to have room for a lift. Or, we are doing a garage addition to our current place to accommodate one. I turn 40 next year so... Murtaugh's words are starting to ring truer and truer.



Here's me after finally getting the old transmission out. I think it was 2AM

[crystalworks]

Got some more work done on Monday. Put in about 3 hours doing various things.

Finished the fuel filter install. That was an ordeal that I had started on Saturday because the 5" rubber line that U-turns after the filter was cracked and started leaking after I had disturbed it. "No problem" I thought. I'll run to O'Reilly and pick up a small piece of fuel line. Nope, nothing will make that radius without kinking. Ugh, guess I'll have to pick up that piece from BMW. $85 later I had it as they do not sell the rubber portion separately. You have to buy the whole plastic piece too.

Also got the motor mount arm reinstalled and both new motor mounts in place. The engine can now rest on its own mounts for the first time in a couple of months. Haven't torqued anything yet as I anticipate having to move things around a bit while trying to get the EGR cooler and sensors back in place on the DPF. That should be fun...

05/10/2021

• Fuel filter and line installed
• RS Engine mount arm installed
• Both engine mounts installed loosely to engine arms

I think Continental custom makes that small fuel line in that shape using a form. I could not get anything to make that radius.





This shows condition of LS motor mount. Not failed, but like the other side, has some obvious droop to it.



This is the steering shaft that you have to be wary of when lowering the subframe. You don't want to damage the seal that that shaft rides in or you will have a power steering fluid leak. Best to undo the steering rack (4 hard to reach nuts/bolts) so you can limit the amount the rack drops.







You can see all my pink torque markings on the fasteners that have been done. Still need to torque the arm down, the one bolt behind the DPF is an absolute PITA to get to. Should be fun trying to get a torque wrench on that.

[crystalworks]

With a summer trip/family reunion coming up wife has been working crazy hours, which means I put in OT with the munchkins so the truck progress has slowed. It's being made, just slower, only able to put in a couple of hours a few days a week after the kids go down. Will update when I have a chance.

But I did make this video with the DPF cleaning results for anyone interested. Ours turned out pretty clean so not sure the $400 was well spent, but I don't regret it just for the clean bill of health it got. As I've said, this is the last time I'm going this deep on the truck so that sucker is staying there now that it's bolted back in and torqued.

166000 Mile DPF Cleaning Results

[crystalworks]

Still trudging along. A couple of hours a day here or there. Only support left on the drivetrain is the trans jack as I prepare to reinstall the Xmember for the Xfer case. Some accomplishments and tribulations:

05/17/20201-06/01/2021

• DPF mounted and torqued down
• Secondary EGR cooler installed and torqued
• All EGT sensors and pressure sensors installed and torqued
• Coolant lines for EGT reinstalled and added 3qts of water, will add BMW blue later
• Reinstalled SCR injection tube/mixer onto DPF
• Reinstalled wiring harnesses/clips on trans
• Motor mounts torqued onto subframe
• Subframe torqued onto chassis
• Steering rack torqued onto subframe
• Installed new actuator gear into the actuator (no errors, but preventative maint)
• Reinstalled actuator onto Xfer case
• Torqued rear driveshaft and new rear guibo onto Xfer case (torqued CSB too)
• Cleaning heat shielding and under trays - reinstalling as I go
• Brief cleaning under the body because why not
• Started working on vacuum line replacement (debating to take off intake manifold)
• Replaced pressure converters (VNE are OE supplier apparently as BMW was scratched off new part)

[crystalworks]

Teaser pic... I'll have a full recount of the weekend's work which culminated in the below.



We put ~70 miles on the truck today.

[Sophisticated Redneck]

Congrats on the rebuild and respect for all of your work you did! I have 170K on mine (ZF8HP) and unfortunately it had issues already when I bought it over 80K miles ago. I have nursed it along with new solenoids which made it usable again some 40k miles ago but I know soon I will have to bite the bullet and pull it for a complete rebuild.

Its a real shame BMW lies about the lifetime oil. I think the ZF's could easily get 300K+ miles out of them were if not for that B.S. and oil changes were done at normal intervals.

[crystalworks]

Originally Posted by Sophisticated Redneck

Congrats on the rebuild and respect for all of your work you did! I have 170K on mine (ZF8HP) and unfortunately it had issues already when I bought it over 80K miles ago. I have nursed it along with new solenoids which made it usable again some 40k miles ago but I know soon I will have to bite the bullet and pull it for a complete rebuild.

Its a real shame BMW lies about the lifetime oil. I think the ZF's could easily get 300K+ miles out of them were if not for that B.S. and oil changes were done at normal intervals.

I agree Sophisticated Redneck, a real shame on BMW's part. Unnecessarily shortens the life of good transmissions, and by relation, the vehicles they are in as many owners trade/scrap/punt the vehicle after failure. Sounds like class action material to me... but who has the time or money?

I will update this with the final repairs/maintenance that got finished the project off eventually. The X5d drives amazing but I am currently working on getting ISTA running so I can work through the SCR repair plan. I neglected to do a reset of the NOX/SCR system before putting real mileage on the truck and it got pissed and threw an SCR efficiency code. I proceeded to make a second blunder and just reset that code... which triggered the 250 miles to countdown series of codes after about an additional 75 miles of driving.

So I went on vacation with the family in the F15 and will now proceed to work on that. I am guessing it is going to want two new NOX sensors, a drain of the DEF system, and running through the test plan until it's happy again. What's another $700 in sensors? So much for feeling like I got a deal on the $800 trans!

[robinasu]

Question, has your SCR system been temperamental? Why reset the adaptions unless it has an issue?

Great work on the transmission.

[crystalworks]

Originally Posted by robinasu

Question, has your SCR system been temperamental? Why reset the adaptions unless it has an issue?

Great work on the transmission.

Thank you. Was certainly a pain in the back. The SCR system hasn't been too temperamental over 30000 miles. Had a heater circuit code (or temp sensor forget) for the active tank that required installing the "rebuild" kit. Also had a NOX sensor code at the beginning of ownership that was solved with a used NOX sensor. Did not do any coding/programming when swapping that sensor so I must have just gotten lucky that it was reading in spec to what the DME wanted.

Other than the above, not had a problem until now with the "Incorrect DEF fluid" shutdown in 250 miles error. Still working on getting ISTA running on an old laptop to run through the SCR test/diagnosis plan.

[robinasu]

Yeah, ok- got it. Sounds like the SCR tank system might be dosing correctly (or at least it thinks it is) and it's not seeing the expected NOx reduction. With your maintenance history maybe you can see if that "new to you sensor" can be coded if the test plan says it needs to be. I think you know this, already. I've read the SCR catalyst gets gunky and some people soak it in a solution. There are YouTubes about it. Gotta be careful not to etch off too much, though. Never done it, but I will try if I ever have to.

[crystalworks]

Originally Posted by robinasu

Yeah, ok- got it. Sounds like the SCR tank system might be dosing correctly (or at least it thinks it is) and it's not seeing the expected NOx reduction. With your maintenance history maybe you can see if that "new to you sensor" can be coded if the test plan says it needs to be. I think you know this, already. I've read the SCR catalyst gets gunky and some people soak it in a solution. There are YouTubes about it. Gotta be careful not to etch off too much, though. Never done it, but I will try if I ever have to.

Currently my SCR system is not dosing at all. Once the "Incorrect fluid" error is triggered the system will not regen. Period. Needs to run through the entire test plan in order to be eligible for regen again.

I am guessing that while the truck was down for 16 months the DEF fluid expired... and/or the exhaust had water in it when it was off the truck and fouled the NOX sensors. Quite a bit of water poured out when remounting the exhaust system. Hope it didn't damage the SCR catalyst. That would suck. But only way to find out what is really complaining is to get ISTA running and go through the long test plan in the driveway.

Edit: Carly will not force a regen due to the codes being constantly triggered. Maybe I'll have someone ride with me and keep clearing the codes. Carly might regen after that. From what I am reading this is a common problem after opening the system up and having the DPF cleaned. I guess the system just gets out of whack regarding before vs. after readings on the NOX and the system gets confused.