4.8is transmission journey from broke to ballin'

[Johnny_5]

Originally Posted by PropellerHead

I'd spend a lot of time retelling the story of my journey starting in 2004 from a 2004 3.0 to my epic find of a 12k mile 2004 4.8is in 2011. But most of the regulars have heard that.

I even wrote about some other dirty little secrets I've talked about- and read about from others- here on the board.

• The seemingly random gear shifts that happened even in manual mode (impossible). I wrote about that somewhere around here, too.
• The transmission hanging on to a gear in Sport Auto mode so long that it was silly. (I could not ever find a way to describe this)
• The ultra-hard 1-2 shifts on a cold motor in cooler weather- <40 degrees F.
• The flashing check engine light and ridiculously rough idle at the same temps. All was fine after warm up that same cold day.
• That weird downshift at highway speed that made it feel like you'd dropped a whole transmission.
• The slipping feeling that would come up at random shift points in city traffic.

Some of the things I kept to myself. I either couldn't describe it just the right way or I'd read that the problem was a solenoid, new transmission fluid, a filter, a TQ converter, or one easy to understand DIY fix or another.

I never wanted to admit that I'd accepted driving my dream X5 was only about 95% as much fun as I'd hoped for. But I read and I read and I read that BMW just got it wrong on E53. Transmissions, sunroofs, window regulators, seals, and the N62. All wrong. I was forced to admit within my own head that I sold a well sorted 3.0 with no problems for a low mileage 4.8is that was fast as balls and drove like a dream once it warmed up. What's the occasional hard 1-2 shift between seasons anyway, right?

So, after the around town slips became a bit more frequent, and with our 2nd wild West ~6,000 mile Summer '15 trip looming, I decided to take it in once and for all. I would confess to my friend and trusted indy of nearly 20 years that I didn't like cold 1-2 shifts. I would confess that it was slipping around town and that very unsettling slam at highway speed down shifts. I would accept and start planning for a $7000 withdrawal from the I-drive-a-V8-E53 fund.

Oh yes, I was going to keep it. I just needed to do some planning. Maybe delay the '75 2002 restoration while I fix up the yard and the X5. Hands off my supercharged E39. That's not going anywhere.

So, about 6 weeks ago, colder weather at the ready, I dropped it off as I left town. Take your time. If it's $16k, maybe I don't keep it. Maybe the dream is over. Maybe I can find a nice 2014 like my brother did last month.

Here's where it got great:

Trip 1:
Drop the tranny, replace a gasket that frequently fails and causes rough shifting. Gasket not obviously damaged. Transmission fluid flush and fill. Same filter- replaced ~25k ago. Agree to replace filter and fluid at next interval- ~90k miles.

Mark off driveshaft to look for slippage. None found.

Diagnose rough idle through codes. Replace engine module that handles the same items as faulted in codes.

Diagnose air suspension. I heard audible air leakage while parked. Turns out this was a wheel problem. Found some leaking stems. Leveled the suspension.

Cost: $700

Result: No rough idle! No more rough 1-2 shifts when cold! Sport auto mode WORKS without hanging on to a gear like a freshman virgin does a senior suitor. It was SO nice! I was happy! But could I be MORE happy?

The slip returned. But while we were screwing around with other cool things like getting the windows to roll up with the key, we found a new transmission code may be the solution.

Trip 2:
Level suspension again based on tires that retain air.

Check markings on drive shaft. X Drive is known to be thrown when a wheel (or two) is out of sync with the others. No slippage found.

Cost: $0.

Result:Level suspension. Slippage around town reoccurs. No rough idle. No rough 1-2 shifts. Rough shifts at highway speeds not observed.

Trip 3:
Apply transmission update from trip 1. Programmed with transmission firware(?) update.

Alarm suddenly tripping after like 1 min armed. Disconnect hood switch. Problem solved.

Cost:$200

Result: It's a whole new ride! I can run around in Sport Auto mode and not wonder when it will shift! A cold morning renders spot on 1-2 shifts without shake or CE lights. I'm so used to driving cautiously under these conditions that I find myself forgetting I have a 'normal' car again! I can get in on a ~55F morning, no shake at idle, and hammer that 1-2 shift in sport! It acts like it's SUPPOSED to.

So, yes. Maybe BMW *did* get it wrong on a few combinations of software, hardware, and usage conditions, but I came to realize something *very* key:

By now- and probably while the E53 was still in production- BMW figured out how to fix it. They released firmware, they issued new parts, and the well trained, curious, and experienced independent network has the ability to solve these problems. We just need to offer them the chance to fix them.

If you're putzing around in what used to be the SUV flagship for BMW and you're having these little issues that drive you nuts, take some time. Find a mechanic that owns one. See if he can download updates n addition to parts at the problem. Ask about his diagnostic process.

I was completely floored that my rough idle was a $100 engine module. I was equally surprised to find my transmission woes solved with a $30 part and some firmware.

If it sounds like I am happy to have dropped $1000 on my E53, you're damn right I am. Not only is it way better than I expected, I faced my fears head on and got an answer that surprised me:

The E53 is supposed to act like any other BMW. At this point, all that is keeping it from the full potential is the owner and- where necessary- the right diagnostic partner.

Whats the $30 part you bought for the transmission and firmware? Im still looking for a indy to do the firmware but have no luck so far locally other than the stealers!

[mam4.6]

AWESOME! Truthfully, I wonder if a lot of us don't put up with some of these quirks, because we're scared of what we'll find, based on what we read here. But, I'm 200% agreed with you, the fixes are possible with the correct mindset and diagnosis. To many times, the ''cheap(est)'' parts get thrown at it, based on someone else's ''exact same problem.'' This is a great forum, and has its place, but as BCREDLINER (I think) stated so many times already, all the problems we read about scare the crap out of us, and we don't enjoy our rides as they were made to be enjoyed!

I'm hoping my Indy will do as good as yours did. I was quick to mention the word ''rebuild'' when describing my transmission hanging on to gears. He was just as quick to say ''update''. I'm hoping this year will be a good one for my X.
BTW, I enjoyed your little ''confessional''! Thanks for sharing...

[PropellerHead]

Originally Posted by Johnny_5

Whats the $30 part you bought for the transmission and firmware? Im still looking for a indy to do the firmware but have no luck so far locally other than the stealers!

OK- I found the part in this diagram (#2). It was pretty easy once I actually looked for it:

[Johnny_5]

Originally Posted by PropellerHead

OK- I found the part in this diagram (#2). It was pretty easy once I actually looked for it:

Wow im absolutely amazed that was the cure for the hard shifting! Ive been having that hard shifting from first start to 2nd when cold and its still driving me nuts!!! My tranny shop that did the filter change stated he would have to rebuild the tranny but would just drive it till it completely craps out. If this is a fix and if they don't charge me an arm and a leg Im all for it but I would really love to find a indy like the one you have who owns and knows these cars!

[PropellerHead]

Originally Posted by Johnny_5

If this is a fix and if they don't charge me an arm and a leg Im all for it but I would really love to find a indy like the one you have who owns and knows these cars!

Remember, these parts are n different cars with the same motors. Not 100% on the transmission parts rt now, but the 545, 645, 745 should all share common problems and solutions.

They did have to drop the transmission to get to this part and then refill with new fluid. Access to this little thing was the lion's share of the $700 bill.

[upallnight]

Originally Posted by PropellerHead

Remember, these parts are n different cars with the same motors. Not 100% on the transmission parts rt now, but the 545, 645, 745 should all share common problems and solutions.

They did have to drop the transmission to get to this part and then refill with new fluid. Access to this little thing was the lion's share of the $700 bill.

That parts looks like a seal for the valve body. I was always under the impression that you could remove the valve body without taking the tranny out of the X. I could be wrong on this since I never had the hard shift issue with my GM tranny.

[fmugur]

Originally Posted by upallnight

That parts looks like a seal for the valve body. I was always under the impression that you could remove the valve body without taking the tranny out of the X. I could be wrong on this since I never had the hard shift issue with my GM tranny.

It seems that way. Phill calls it bridge seal. Check the following detailed thread. No need for the tranny to come out just the valve body.

ZF 6HP26 Teardown

[Johnny_5]

Originally Posted by upallnight

That parts looks like a seal for the valve body. I was always under the impression that you could remove the valve body without taking the tranny out of the X. I could be wrong on this since I never had the hard shift issue with my GM tranny.

That piece is on the valve body. The valve body should be able to remove with the pan and filter dropped and without the transmission being removed. If Im not mistaken Ive heard its not that hard but has wires and other things going to it which I scared to even try it. If there was a diy that's another story but doesn't seem like anyones ever removed the valve body on these.

[PropellerHead]

Originally Posted by upallnight

That parts looks like a seal for the valve body. I was always under the impression that you could remove the valve body without taking the tranny out of the X. I could be wrong on this since I never had the hard shift issue with my GM tranny.

I think you're on target. Maybe I heard drop the tranny because they figured it was shorter for me to understand. That's fine- Either is more than I can do- or have tried.

But they did need to replace the fluid which is also pretty expensive. It makes getting at this inexpensive part more than just replacing it.

[Doru]

Originally Posted by Doru

Mike, there could be several things that could cause the hard 1-2 shift. I pdf'd the page, and once I'm home I will post it.
In my case, I knew my tranny was OK (it was serviced not too long ago, and had some minor parts changed). All of a sudden it started to have the 1-2 hard shifting. Really bad.
I tried connecting the laptop, it would recognize the car, it would communicate with all modules except the tranny, no matter what I did. This wasn't my first experience when the cars modules would get "corrupted/buggered up". So I removed the battery cables, touched both leads and re-attached to the battery. After this, I was able to communicate with the tranny module and reset/upload the latest software.

With the ZF 6HP26 tranny (facelift vehicles) there is a caveat: These cars DO NOT HAVE the EGS module like the previous versions. The electronics module is contained within the mechatronics. This module is called different and you HAVE TO SELECT that module. I will revisit this post tonight with the correct name and a pdf I made on how to upgrade/re-install the software on these cars. There is a specific set of codes (numbers) you have to type in once you select the correct module (Progman SSS or GT1).

I also read numerous posts on the net where people "had to" change the whole mechatronics module in order to fix the transmission jerk. What I think happens, is they didn't know about the pdf I will post when I'm back from work, and maybe didn't know about the fact that the transmission module is sealed inside the mechatronics. Basically earlier cars = control unit (in the tranny) + EGS. Facelift cars: mechatronics (which has the control unit + EGS which is called different in the same unit).

If you somehow manage to select EGS and try to update that one in a facelift car, either you cannot do it, or if you can (I doubt it) nothing will happen, and the jerk will never be fixed. Resetting the adaptation values via the key in Pos II with the gas pedal all the way depressed for 30 seconds will NOT address the issue, because in this instance, the car also cannot communicate with the module inside the mechatronics. As I said in order to reset it, you take off the battery cables.

These corruption of modules can happen on any car that might exhibit a slightest battery drop combined with I don't know what - probably a sudden big electric consumer that kicks in at that particular moment. As I said, I had this happen on 2 of my cars (e46 & e53). Also, this issue is probably why BMW switched to the awkward "battery registration" on newer cars, because they have an extra module that keeps tabs on the state of the battery - probably that module does not allow electronically to get modules corrupted by lack of electric juice.

I will post later the correct procedure on how to reset the tranny and get rid of the 1-2 hard shifting. It worked great in my case.

Cheers

Originally Posted by Doru

When the 6HP26 tranny came out and was installed on various BMW iterations, most of these cars exhibited the 1-2 hard shift issue. BMW tried fixing it with I think 1 or 2 different software which failed. The last version of the software, however fixed this hard shifting issue. I am not sure which the number is or what year it was (sometime between 2007-2009 I believe), but if you have the latest GT1/INPA/Progman SSS, then you should have this version. When I re-flashed the tranny, I know I had the latest, but as I said it "glitched" and went in the 1-2 hard shifting mode, but I omitted to write down the software version.
If the vehicle runs fine, don't touch it. If for whatever reason it starts to exhibit the 1-2 hard shifting pattern, the first step is to re-flash the tranny module. When doing it with the latest GT1/Progman SSS software, when programming, the software will prompt you what software version will be replaced. In my case it was replaced with the same software, so I know I had the latest.

I found the link with the 6HP26 issues and possible fixes. Tonight I will update with the pdf on how to program the tranny and the numbers you have to use for the different 4.4 and 4.8 transmissions.

Originally Posted by Doru

Sorry guys for being late, but there was some playoff hockey I had to attend, and my Flames just burned the Canucks. I hope they will manage to burn them another 3 times. Go Flames!!!!

So attached is the pdf. If you ever have the 1-2 hard shift situation, and you know 100% that the ATF level is good and the filter is not clogged, just try to re-flash the latest software. This is for the 6HP26 transmission with Mechatronic.
When programming, you have to select GKE (as opposed to EGS in pre-facelift models). The software later will ask for some numbers to process in the EGS (although you selected GKE), but this is normal. Read very carefully the attached pdf, because it spills out the exact numbers that have to be entered for a 4.4 or a 4.8 model. The pdf is SIB 24-01-06

Attachment 66167

Above my 1-2 hard shift fix.
I know about that rubber seal, the thing is that lots of the time the battery can get low voltage, corrupting the car's modules. And sometime you cannot even connect to it. I just re-flashed the latest tranny software and this fixed the annoying 1-2 jerk when cold. I would try this first, before dropping the mechatronic unit. If this doesn't do it, then it could be the bridge seal, or low ATF, or clogged filter. Fmugur can chime in, he was there.

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