Transmission issue 8HP70X

[Pruzina]

2011 X5 50i (150k)
8HP70X

DTC
4EC8 - Position sensor
4EC9 - Parking lock
4E98 - Transmission ratio monitoring, clutches A, B and D

Here are the exact symptoms:
When cold throws 4EC8 (position sensor) car drives forward and backwards and possible engage Park

After couple minutes D and R not engaging shifts in N (N is flashing) unable to shift in to P

Checked tranny fluid and is full but the fluid is really really dark and the filling plug was almost impossible to loose so clearly fluid never changed.

First thing what I'm about to try is to change the fluid and filter but I'm not expecting that it will solve the problem.

Seems like pressure issue. once the fluid warms a little won't shift.

Does anyone know if it's worth to do valvebody rebuild and solenoids?
Really don't want to spend money on rebuilt and solenoid kit just to find out that the internals of the tranny are shot. I rather skip that part and get another trans.

[Sophisticated Redneck]

Originally Posted by Pruzina

2011 X5 50i (150k)
8HP70X

DTC
4EC8 - Position sensor
4EC9 - Parking lock
4E98 - Transmission ratio monitoring, clutches A, B and D

Here are the exact symptoms:
When cold throws 4EC8 (position sensor) car drives forward and backwards and possible engage Park

After couple minutes D and R not engaging shifts in N (N is flashing) unable to shift in to P

Checked tranny fluid and is full but the fluid is really really dark and the filling plug was almost impossible to loose so clearly fluid never changed.

First thing what I'm about to try is to change the fluid and filter but I'm not expecting that it will solve the problem.

Seems like pressure issue. once the fluid warms a little won't shift.

Does anyone know if it's worth to do valvebody rebuild and solenoids?
Really don't want to spend money on rebuilt and solenoid kit just to find out that the internals of the tranny are shot. I rather skip that part and get another trans.

Most likely Solenoids, mine started to fail around 120K miles, replaced and now nearly at 180k. Recommend picking up ATSG manual. Order new Solenoids and b clutch mechatronic sleeve, change oil & filter and excellent chance you can get another 100K miles out of it.

[Pruzina]

Yeah that's probably the best idea to do it first. I was actually thinking to clean the solenoids change the oil and filter and see if it improves. If yes then I would order new solenoids.
My problem here is that I don't wanna spend $500 on solenoids and find out that it didn't solve the problem and then pay $1000 for tranny.
So my main question is how big of a chance is that the solenoids are the culprit. If the solenoids would fix the issue I'll be more than happy.

by "b clutch mechatronic sleeve" you mean the sleeve which goes on the outside of the transmission around the wiring connector?

[Sophisticated Redneck]

Originally Posted by Pruzina

Yeah that's probably the best idea to do it first. I was actually thinking to clean the solenoids change the oil and filter and see if it improves. If yes then I would order new solenoids.
My problem here is that I don't wanna spend $500 on solenoids and find out that it didn't solve the problem and then pay $1000 for tranny.
So my main question is how big of a chance is that the solenoids are the culprit. If the solenoids would fix the issue I'll be more than happy.

by "b clutch mechatronic sleeve" you mean the sleeve which goes on the outside of the transmission around the wiring connector?

At 150K miles, replacing solenoids is a must. Do not try to just clean, the internal o-rings and seals are the issue not to mention coils may be failing and plunger issues. Its worth every penny to replace and first thing to do when trouble shooting plus you would not want to use old solenoids in a rebuilt transmission should it come to that.

Solenoids and the mechatronic sleeve are about the only thing you can do besides basic oil change and filter before it gets serious. You can try the sonnax zip kit to and they have equipment the test the valve body too. I didn't see much difference when I did the zip kit and its alot of work to install so only use if solenoids don't fix. After that if you still have issues then its a complete tear down and rebuild. Replacing the solenoids is pretty straight forward but do get the ATSG manual, I would not attempt without it. Link to mechatronic sleeve below. Its sandwiched inbetween the valve body and transmission.

ZF Part number: 1087301006

Ebay link (only place I have ever found them): https://www.ebay.com/itm/324432302933?epid=19033072148

Best price for new OE Solenoids I found: https://www.thectsc.com/products/sol...n-244-107.html

BTW, I am 25K miles in using the Liqui Moly top tec 1800 transmission fluid. Havent noticed a difference over the original ZF fluid. Will save quite a bit of money. You will need 8 liters as when you remove the valve body, about 2 more liters comes pouring out so expect nearly 8 liters to replace it all. Make sure you download instructions or watch videos on how to replace fluid in the ZF8hp. Fun times ahead being under truck while its running stuffing in the last liters.

[Pruzina]

Thanks for all your info.
Just want to state that. I've serviced replaced multiple BMW transmission (mostly 6HPs) so I know the basic. Sleeves, Solenoids, Oil change, how to fill etc.
What I actually meant by cleaning solenoids was that I didn't want to spend money on new solenoids just to find out that the guts of the transmission are toasted. Bcs if that's the case I'm not rebuilding this transmission I'll get different one.

Anyway non of that matter anymore. I dropped the pan and valve body today and I couldn't believe what I saw. I've seen a lot but this just left me speechless (see next post) not mentioning the color and horrible smell of the fluid. Which didn't surprised me after I saw what's inside.

Btw I'm using Valvoline dextron VI. Never had single issue with that one.

[Pruzina]

https://youtu.be/4cczImXUbzs

[Colodano]

Well, solenoids aren't fixing that...

Now I am really happy with how my 6hp28 looked when I pulled the pan. Of course I was trying to go cheap and troubleshoot so I just swapped solenoids around along with a fluid and seals change and my shifting issue followed the solenoids, so guess what I am replacing today..at least I will have peace of mind with 2 fluid changes in 2 weeks as well as the new solenoid kit.

[Pruzina]

Well they definitely aren't.
With 6hp's if you address problem before it gets worse seals bridges, solenoids and new fluid and filter usually fix the problem.
Happy you got yours fixed fairly cheap.

[Pruzina]

After further inspection under the car all is starting to make much more sense.
Still can't believe what's under there.

My theory here is that the guibo (bolts) failed and did all the carnage around the transfer case. And before the complete failure when guibo was severely compromised there was crazy amount of movement and vibration of the driveshaft transferred on transmission output shaft which damaged the transmission. What do you guys thing?

What's wrong with people that they let something like that happen? There had to be noticeable noise from the driveshaft and transmission.

I can't believe that the car made it in to the garage on it's own.

[Colodano]

Originally Posted by Pruzina

Well they definitely aren't.
With 6hp's if you address problem before it gets worse seals bridges, solenoids and new fluid and filter usually fix the problem.
Happy you got yours fixed fairly cheap.

Yup I was definitely cautious, basically parked it after 2 weird shifts. Got my solenoids changed today, another round of new fluid and it is back to normal, aside a bit of learning the new solenoids, so super happy.

That definitely looks like there was a big vibration and wear leading to a busted guibo, and that can transfer all the way up and shock the transmission, I bet all of the bushings are beat, and let the clutches wear abnormally.
Did you buy the vehicle in this condition?
For work I see lots of inspections on broken vehicles, and the things people just drive through are so amazing.

[Pruzina]

Yeah it's definitely good learning experience. I did my first transmission fix just learning from YouTube. And if you know how to wrench and has little bit of common sense it's not all that difficult.

Yes I bought the car recently knowing about the transmission issue basically knowing it will need most likely new tranny so it's not all that big of a deal. It was more surprising learning why it happened. Question is if the transfer case is shot too.
Little surprise was that I can't find this tranny anywhere near me that's a problem.

Hopefully I got the car super cheap so I'm not complaining.

Yeah people are crazy. They absolutely not realizing that by not doing repair worth couple hundreds bucks they are looking for thousands down the road.

Then they selling broken car for 30% of it's value complaining what a piece of $hit bmw is when in reality they are the stupid one

[crystalworks]

Originally Posted by Pruzina

Yeah it's definitely good learning experience. I did my first transmission fix just learning from YouTube. And if you know how to wrench and has little bit of common sense it's not all that difficult.

Yes I bought the car recently knowing about the transmission issue basically knowing it will need most likely new tranny so it's not all that big of a deal. It was more surprising learning why it happened. Question is if the transfer case is shot too.
Little surprise was that I can't find this tranny anywhere near me that's a problem.

Hopefully I got the car super cheap so I'm not complaining.

Yeah people are crazy. They absolutely not realizing that by not doing repair worth couple hundreds bucks they are looking for thousands down the road.

Then they selling broken car for 30% of it's value complaining what a piece of $hit bmw is when in reality they are the stupid one

So true. So many people want to treat Bimmers like Toyotas. @ 150k guibos and CSB are minimum 25k over due. That vibration going through the transfer case must have been intense. Best of luck with your repairs.

[TRENDSETTER]

Excude my ignorance but Wtf is a guibo?

[Pruzina]

Flex disc. Rubber circle between transmission output shafts and driveshaft.

[TRENDSETTER]

Thanks for the info. Never heard of rubber discs between driveshaft connections before. Seems like something that would wear out pretty quickly.

[crystalworks]

Originally Posted by TRENDSETTER

Thanks for the info. Never heard of rubber discs between driveshaft connections before. Seems like something that would wear out pretty quickly.

It's a German car thing. But they typically last at least 100k, so, longer than you would think it would. The center support bearing on the rear driveshaft usually goes before the guibos (flex disks) and so is a good time to do all 3.

[TRENDSETTER]

Hmm. Thanks for the info. So is it safe to assume once these start becoming an issue you would begin to feel some kind of vibration in the driveline?
And guibos just sounds more italian than german to me fpr some reason. An odd name for a something but what do I know other than english

[Pruzina]

Today I did little more inspection under the car and things got even more interesting. Starting to believe that the flex disc (guibo) was not the initial reason of the failure. As you can see in picture below the god damn bolt holding the transmission/transcase to the crossmember is missing so you can move everything with no effort. So you can imagine how violently the engine was rocking back and forth every acceleration and deceleration as it's not connected to the car at the end of the transmission at all. So the whole drivetrain is hold in place only by two engine mounts and driveshaft. That's just batshit crazy that someone was driving the car like that. Freaking monkey would realize that something is seriously fu**ed up.
You can rock the engine by hand back and forth like crazy with no effort at all.

So either that got lost in the first place (no idea hot that happened) then the flex disc failed and along the way the transmission and the other bracket and CSB and who knows what else.

Or someone forgot to put the bolt back after the damage and all the Mickey Mouse repairs.

The transcase mount feels pretty soft (new) but can't really see I'll confirm that when tranny is out. Hopefully next week.