Everything about your ZF automatic transmission issues

I have found this amazing article about the transmission in BMW E90’s so I’m re-posting it here in my blog with updated pictures and part numbers to match ZF 6HP21.

So if you want to maintain your transmission you should read it even if you don’t have any problem in your transmission right now.
Credit goes to : BMW Logic7 site

It applies to all BMW with ZF 6HP19/ 6HP19Z / 6HP21 aka GA6HP19TU
In this post i will be explaining why you have transmission issues like:

-harsh shift 2-1

-not able to shift into park when hot

-weak torque feeling

-transmission faults

All highlighted problems you can experience even on low miles cars less than 70-80k, it depends on at what speeds your car mostly runs. On the highway this transmission will easily last 200-300k miles.

So you hate the way transmission shifts and workshops didn’t find any faults and they told you it is what it is and this is how it is intended to work!

In fact ZF 6HP21 is a very good transmission, powerful, bullet proof pretty much if serviced in time and proper fluid pressure maintained! This transmission is still considered one of the best and has carbon clutches vs cheap paper ones you can find on Japanese cars. But this transmission has very serious and very important weak spots you have to take care of:

-First thing first, check transmission temperatures

If it is higher than 95C, then most likely you have a problem with transmission cooling system or your engine cooling has some leaks causing running it very hot.

Usually high temps indicate following:

1) engine cooling system problem- air bubbles or airlock.

2) if everything is good with cooling system, check your transmission oil cooler- it gets clogged up pretty often and also indicates that some clutches or Torque converter clutch is worn out and that debris clogged oil cooler.
17217536929_335i_only

3) worn out Torque converter clutch slipping overheating transmission fluid.

Your good engine temps are 103-105C and if it climbs to 107-110C in traffic, it means you’ve got a leak :

-lower radiator hose sensor leaking (usually shows a white residue around the sensor).

-valley pan under intake.

-rear cover plate between transmission and engine. Very common after 100k or 8-10 Years.

-coolant tank cracked.

-radiator cap leaking pressure.

-coolant pipe seal leaking.

-other cooling issues.

It is very important to keep temps in specs not only because of few degrees, but because with leaking cooling system lose coolant pressure introducing air in the system, causing uneven cooling and overheating both engine and transmission. Good OEM specs are 103-105 cycle when idling and lower hose should be hot around 60-80C. When you drive it tstat is controlled by ECU therefore it keeps it cool on the freeway.

Easy way to test your cooling system

1)Disconnect aux pump connector assuming aux pump is working (they fail often).

2)Drive your car to warm engine well.

3)Turn on heater on hot but low speed.

4)check if you get hot air from vents for 10 minutes.

5)If after a minute you noticed your heater is not hot anymore, it means you’ve got a leak!.

6)This Engine has self bleeding cooling system, which means you cannot get air pocket if system is well sealed.

So if engine temps are good and transmission still runs hot 100-110, it means heat exchanger is clogged with transmission clutches, Torque Convertor wear and tear dirt. Replace it and check if it got better. This transmission will die quick if temps are not good.

– MECHATRONIC Adapter Seal

This adapter (number 2) usually lasts only 60-70k miles. Replace it every 60k miles even if transmission shifts well. It is very important because it keeps your mechatronic valve body under specified pressure therefore it controls how clutches are pressed! Which means if your gasket is weak your transmission clutches are not pressing well on each other causing premature wear and tear, also transmission pump and TC clutch will be affected.
This square seal also can crack, in this case you will get transmission fail safe errors and even clutches slipping errors, causing very quick transmission death. don’t drive your car if you’re getting any transmission faults, even after restart transmission errors go away for a while, it is not a transmission computer glitch!!!

Mechatronic Seal Adapter late 6HP19 & 6HP21
BMW part number : 24347588724
ZF Part number : 0501 215 783

YES THIS SMALL, CHEAP GASKET CAN DAMAGE YOUR TRANSMISSION PRETTY BAD

-4 Rubber Seals

They are 5,6,7 also controls clutch pressure, but even if they are flattened, pretty bad transmission won’t give you any errors. Its always good idea to replace it- you’ll notice a difference how your transmission shifts.

BMW Part Numbers:
24107536339 x 2
24107536340
24107536341

ZF Part Numbers:
0501 319 279 x 2
0501 319 280
0501 319 281

-SOLENOIDS (Pressure Regulators)

1068_298_046

Yes they go bad and are not simple solenoids you used to know from old school transmissions. Now these are pressure regulators and they do not only work open\close operation, they control pressure and after so many time they get clogged, overheat, etc. So if your transmission temps are good and your transmission shifts hard, it could be your solenoids. Its good idea to replace them every 100k, because they control everything in the transmission. You will be surprised how transmission shifts with new solenoids.Also don’t be scared if you open your transmission and find out that color is not the same- relax it changed color because of temps and age.

Unfortunately ZF does not sell the SOLENOIDS kit, you have to hunt for it in some online sites.
You can see that in the parts catalog:
Solenoid_Kit_6HP21

1068298046_1071030003

1068298046

1068_298_046

and you need to replace the protection foam strip with the solenoids:

1068327241
Protection Foam Strip:
ZF: 1068 327 241

A useful document for replacing the solenoids can be found here:
solenoid_replacment_6hp21.doc

A video I made to replace the solenoids:

-Giubo (FLEX DISC)

26117610061

BMW part number : 26117610061

with:

26117526611

Driveshaft Centering Sleeve / Guide bushings
BMW part number : 26117526611

They usually go bad after BMW lifetime period 60-70k.

Common Symptoms:

a) hard 2-1 shift

b) at stop you can hear clunking when shifting from P-R-D

c) overall transmission shifting quality

Check this amazing article: How To Properly Install Driveshaft Flex Disc (Giubo)

-transmission fluid level

Yes due to leaking oil pan gasket you might loose some fluid. Always check transmission oil pan for leaks and transmission fluid level (use BMW sealed transmission fluid level check procedure).

-Torque converter

tourqe
02/06 – 03/07 ZF: 4168 025 487
01/07 – 08/07 ZF: 4168 025 553

Yes it can go bad just like any clutch, because this transmission engages this clutch very early causing premature wear and tear.it can engage clutch as early as at first gear!! That’s why we get decent mpg from this transmission. In other words it is more like a manual transmission with torque converter working only at very low speeds and low rpm. So I would NOT recommend driving it very aggressively in the city, unless you enjoy paying 4-5k for a new transmission. Don’t forget this transmission handles 300-400hp and some impressive torque. Driving in normal mode, Torque converter can last up to 300k miles!!

most common symptoms of bad clutch:

-sometimes when clutch is very bad it will throw 1721 error clutch slip.

-bad MPG. Without TC clutch your car is still drive-able, but you can feel its very weak even though engine feels strong

-after 4th gear tachometer arrow is not steady

-weak pickups, downshifting when driving uphill

-bad slipping clutch will overheat transmission pump and finally will kill internal transmission parts (clutches, valve body, seals, etc)

You can have your Torque converter rebuilt for around 300$, its not as perfect as new, but decent still.

Its a long list of issues, but if you take care of your transmission every 80-100k miles it pays for itself pretty good. Most important thing for this transmission is correct fluid pressure and temps, other parts like clutches are very durable and made with highest quality standard. Don’t forget the same transmission they still install on newest Bentley, Rolls Royce, Audi, Maserati and other luxury brands. This transmission is way more reliable than Mercedes one or Lexus transmissions.

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43 responses to “Everything about your ZF automatic transmission issues

  1. thanks for your page, I’m from santiago-chile I have a BMW 320 series 90e 2006 gearbox is blocked and the scanner indicates problem when reduced to 5-4 up, the problem is that here no one sees these boxes because they are encoded and bmw consecionario Williamson Balfour (www.bmw.cl) charge a fortune to repair or make you change to a new gearbox. the point is that you think that this failing, I have the gearbox open but aside from buying new piesas have to reschedule and that is not done in any machine shop chili.

    agradecere your help and advice

    • Maybe a valve body “mechatronik” failure, try to contact your local ZF branch for a valve body replacement. it will cost you around 1500$.

      Good luck

  2. estimated chile no change valve body will only change the gearbox, you can recommend me where I can buy a valve body in europe and north america online, understand that this must be coded for each bmw my email is operaciones@transunion.cl
    thanks for your help

  3. Hi, I have the same mechatronic as you in the video but you ordered different colour solenoids. In your valve body you have 8 solenoids but you ordered 7 only. Can you advice which one you actually ordered and from where? Thanks. Alex

  4. Hello, The post is very helpful understanding the transmission. My car recently throwed a code p0741 which is Torque Converter Clutch Circuit Performance or Stuck Off but It runs perfectly I cannot notice any symtoms after the codes. Do you have any idea with the code?

      • My e38 2000 740il drives well but every so often it will go into what appears to be sports mode. You have to rev the engine to aprox 3500-4000 to change . Sometimes it may clear up after 10 km but if you stop and let it sit for about 15-20 minutes it will go back to normal. The only reading we get from the diognostic after we plug onto the car is transmission temp sensor. No one seems to know what it may be.

  5. I’m having a problem I feel that when my bmw 325i 2006 shift between gears it somehow delayed and but the big thing is that when I’m trying to make a complete stop I feel like a car is bumping my car from the back and that happen like 98% of the time, do I need to change the Solenoid or what shall i do ? thanks for your help.

  6. Please help me, I’m from Country Georgia and sadly we have got bad gearbox specialists hear. I had problem with my 6hp21, suddenly car lost power and could not put in D or R it put itself in P. Local gearbox shop changed Mechatronic Seal Adapter and oil pump. They said that torne Mechatronic Seal Adapter caused oil pressure drop and broke oil pump.
    After this I test drove my car quit aggressively, everything seemed perfect, shifted perfect and was fine. But after I shut off the car and started again, it begin showing error message “gearbox malfunction, power reduction…..” and stuck in second or third gear, don’t know exactly. What it could be, please suggest anything if you can. I will be vary grateful.

    • Did the mechanic reset adaptations values via INPA or similar diagnostic software after doing the mechatronic seal adapter and oil pump change?
      Did you use ZF transmission fluid or none ZF ?
      You can monitor the gearbox temperature via INPA diagnostic software to see if the gearbox is overheated or not, there is an article about INPA in my blog.

      Good luck

  7. Thank you for replay, after mechatronic seal and oil pump change it gave gearbox malfunction error again. After this Mechanic toled me that he reseted software, but problem was still there.
    I took the car home and decided to take next morning to another gearbox mechanic. Next morning when I started the car, there was no error and everything worked perfectly. Till now everything works perfect. Very strange,
    The car repaired himself. Do software reset need time for reset? What it could be? Have I reasons to worry, the error suddenly to come again?
    Thank you again, for rapid replay.

    • Hi, Don’t ignore the issue, as I told you before… try to watch the gearbox temperature while driving, this can be done by connecting a laptop computer to your car using a cable and INPA software. the gearbox mechanic can do this for you, take my advice… don’t ignore error codes.

  8. Hi, I will not ignore. I drive one week already very hard and no issue. Temperatures are OK. Maybe gearbox computer just needed time to reset after new pump and mechatronic? Just very strange.
    Thank you.

  9. Hi i am from Mauritius. I have a BMW E60 520i year 2005 with M54 engine gearbox 6hp19 now i am having transmission failure on the dashboard. Codes are ratio monitoring clutch A, ratio monitoring clutch C and ratio monitoring clutch 4-3. Can you please help with the codes. Can it be the adapter seal or a mechanic failure inside the box or a bad valve body? What’s your opinion?
    Thanks

  10. Excellent Article, Thank you for posting. Currently getting a p17E1 code. Hoping I can avoid a whole new transmission. 08 335i

  11. Help! Before it gets worse.. I am in Alabama and travel alot so i am starting to notice this problem more often. I am experiencing a hard shift out of first into second and its long and dragged out even when i swap to the slapshift manual mode.. I replaced spark plugs and replaced the oil filter housing gasket. engine is very hot and has been for sometime. I have oil in the coolant system from filter housing gasket issue and i felt like it is finally affecting the engine. what should i do to try to figure out this hard shift.. It might be something minor that im just over thinking.

    To much money invested into this stupid car that i love for some odd reason.. haha
    Thanks for the help ahead of time!
    Chase,

  12. I have Jaguar XF 3.0 V6, same transmission, similar problem, 87 000 on the clock. Started with slipping on 4-3 but no faults, also pan was leaking so the trader fixed the leak and changed oil under warranty, tested for a 10 miles, started slipping and jerking even between 1-2, no faults on the computer. I am without a car for 3 weeks now, they trying to figure it out what is wrong. At least I do not pay for this. I will keep update

  13. I have 2007 335i and my yellow transmission warning light came on. It’s only came on when I’m driving in the city or after an hour of driving. When I try pulling off it’s like is stuck in first gear. The engine revs high. Could this be fixed by changing the shift solenoids.

    If you have a website where we could purchase the solenoids and oil could you please post it

  14. automatic box 6hp19 was overhauled, but now there are no gears at all. Not even if manually selected! What can we the most common problem when overhauling a box and then experience no gears.

  15. hi all, I have problem with my e90 320I, my gearbox seem to be jerky and hard shifting after the car was running for 30minute, but during engine is cold I cant notice any of the jerky issue, transmission shift like normal n very smooth it only happen after the engine was hot. It’s feel so so bad, bumpy and slipping, it noticeable during try to accelerate and during stop at traffic light. what is u guy opinion? is this related to gear oil temp? solenoid? low gear oil? mechatonic? software issue? there is no error form EGS during diagnose, only error that related to valvetronic sensor and my radiator coolant is good, no sign of oil residue or what so ever. engine temp is around 102 C in the city. i’m very frustrated man….why during cold it shifting like a champion but not during hot.

    • Im having the same problems in my E90 325i with 150,000 miles. Did you ever find the problem? Im thinking its a valve body or VB seal issue.

      • mine completely mechatronic module issue, TCM malfunction. I replace with new transmission bring from e90 halfcut from japan.

  16. Hello,i have a 2006 318i e90,recently i noticed that my gearbox keeps overheating after driving for about 100km doing about 120-140-km/h.Just changed the transmission fluid thought that was the cause but it happened again today and after coling off for about 10mins i was on my way with no issues.
    Kindly assist please.
    Thanx

  17. hi i got the red transmission light on in my e90 but there’s no fault code in engine or transmission that’s wrong please?

  18. Hello ,I have a 05 e60 this one York second to first ,first to second speed I check the gildo s fine,when I go realerning the tcm York go out for about 30 40 miles and the York is back again.. Tanks..

  19. Hello, my 2008 335i E90 N54 engine went into limp mode with a “Trans Malfunction” on my navigation screen. I had it checked by a mechanic and he said the trans is good and he believes it’s the valve body that needs to be replaced. The gear got stuck in parking. I can only change gear if I release the gear switch. In this case, when I put the car in reverse or druve, it makes a rough knocking sound. Do you think that the issue can be resolved by changing the valve body or by just replacing all the solenoids to new ones? Thanks in advance…

  20. I have problems with my BMW X3 2.0d -2008 I have high pressure from expation tank may heat exchanger for automatic transmission to be the problem? Is perhaps far-fetched, but do not know what the problem is, is not the head gasket

  21. Dear please need your help i received a refurbushed valve body ZF FOR MY BMW F02 CY46645 the part number is.Zf 1071.198.853 I installed and working but theres vibration when shifting from 3to 4 and upper but when i use manually nothing happen and sport mode nothing happen can you tell me if it is the good valve body if you know what is the reason i need your help
    And even theres no computer fault

  22. Hello,
    I have the ZF6HP28a on Audi.. issue which appears is like half clutch drive when reducing gears from e.g. 6 to 4 and throttle on 60%… the rpms are steade for a while on ~3200 rpm and then it starts going.. Is this something starting to die or normal behaviour? Car heavily tunes.. from 240 PS to 350 PR.. flat torque 650NM from 2100 rpm to 3600rpm…

  23. 2011 BMW 118d getting fault code 4F8A – 4th/5th gear monitoring. Is this likely to be the Mechatronic adapter seal cracked and letting fluid through? Car’s only done 47,000 miles with full service history. Could it be software instead?
    Thanks……great info on the gearbox, much appreciated.

  24. I have a 5HP19FLA in an allroad 2.7T, i just cant get it into manual mode, moving the lever dont makes any difference. the steering wheel buttons dont even light up. thanks for the info and good luck

  25. Hi, ’07 6HP21X (BMW X3) blows front pump lip seal every time you give pedal on the car. This came up after engine replacement. No other weirdos nor symptoms on the tranny whatsoever. Two lip seals gone. Now the tranny is out again and front pump disassembled, nothing visibly wrong there. I don’t get it what makes excessive pressure behind the lip seal?

    Any idea is greatly appreciated. Thanks.

  26. You say its a bulletproof transmission but all I can see from the comments/feedback is that there are more than enough problems with it. The problem with european cars is that they build good cars outside but internally use short lasting components. This is how they make money.

    There are enough Japanese automatic transmissions that only require fluid change that are robust, solid and will take a good beating.

    Japanese engine’s and transmissions are becoming a common swap into European cars but not the other way around. Why you ask? Well its not related to cost but because Japanese are reliable and can take a beating.

  27. Hello,

    Please let me to ask you about my issue; cannot switch P or N from D when hot. ZF 6HP28. How do you see what could be the problem ? Is it bad fluid level only or something serious ?

    Thank you for your help,
    Istvan

  28. I have bmw 7 seireis when I driving slowly showing instrument cluster gear box warning light I went to garrage and scan the car fault code 4f89 clutch 3 4 ratio monitoring pls give me which part gone

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