Everything about your ZF 6HP26, 6HP19, 6HP28
transmission issues
137 Replies
What you are supposed to know about your ZF6HP26, 6HP19, 6HP28 and similar ford
Transmissions.
It applies to all BMW, Jaguar, Bentley, Rolls Royce, Maserati, Audi and others with ZF 6HP26, 6HP19,
6HP28 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 -gear speed ratio faults -other 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 tranny will easily last 200-300kmls. AND EVERYTHING IS RELATED TO
VALVE BODY PRESSURE LOSS DUE TO SOLENOIDS OR ACTUAL VALVE BODY SEALING
GASKETS LEAKING INSIDE, BUT BETTER DO BOTH. DRIVING WITH LEAKING VALVE BODY
WILL EVENTUALLY WEAR OUT ACTUAL TRANSMISSION HARDWARE. BEST ADVICE FOR
YOU: SINCE 99% issues with this trannies are related to valve body fluid pressure loss, I strongly
recommend new (re manufactured) valve body from ZF (expensive 1600$), (you can find some companies
offer this rebuild, but they charge almost new VB price, or rebuild it yourself with NEW SOLENOIDS
PACK (300-400$) and SONNAX zip kit (150$). If after you rebuilt or replaced valve body and RESET
ADAPTATIONS USING BMW SOFTWARE INPA OR ISTA IS A MUST, OR YOU WON'T SEE
ANY DIFFERENCE AFTER REBUILT, BECAUSE TCM KNOWS VALVE BODY PRESSURE
VALUES AND THEY MUST BE RESET. IF AFTER REBUILT, it's not shifting well, it means YOU
WAITED TOO LONG WITH VALVE BODY REBUILT AND DESTROYED transmission hardware
(bushings or actual clutches failed) and you need to rebuild it, but like i said main problem STARTS at valve
body and then if not fixed in time you get worn out transmission. All those jolts, bumps or harsh shifts cause
premature wear and tear on your tranny. Rule of the thumb is not to drive it if it jerks,or shifts wrong.
replacing just solenoids without rebuilding valve body, where accumulators/pistons always go bad after 6070k, will not get you perfect results, but might improve shifting quality. Remember-cheap people usually
pay twice (no offense). So you hate the way tranny shifts and dealer and other shops didn’t find any faults
and told youit is what it is and this is how it is intended to work! Well it is total lie they are trying to get rid
of you with. In fact ZF 6HP26 6hp19, 6hp28 is a very good transmission, powerful, bullet proof pretty much
if serviced in time and proper fluid pressure maintained! This tranny is still considered one of the best and
has carbon clutches vs cheap paper ones you can find on Japanese cars. But this tranny has very serious and
very important weak spots you have to take care of: -First thing first check tranny temperatures. If it is
higher than 95C, then most likely you have a problem with tranny 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 bauble or airlock 2) if everything is good with
cooling system, check your tranny oil cooler- it gets clogged up pretty often and also indicates that some
clutches or TC clutch is worn out and that debris clogged oil cooler. 3) worn out TC 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 tranny and engine. Very common after
100k or 8-10yrs. -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 you lose coolant pressure introducing air in the system, causing uneven cooling and
overheating both engine and tranny. 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 tranny still runs hot 100-110, it means heat exchanger is clogged with
tranny clutches, TC wear and tear dirt. Replace it and check if it got better. This tranny will die quick if
temps are not good. -MECHATRONIC ADAPTER SEAL.
This adapter (number 2) usually lasts only 60-70kmls
(BMW lifetime). Replace it every 60kmls even if tranny 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 tranny clutches are not pressing well on each other causing premature
wear and tear, also tranny pump and TC clutch will be affected. This square seal also can CRACK, in this
case you will get tranny fail safe errors and even clutches slipping ERRORS, causing very quick
TRANNY DEATH. DON'T DRIVE YOUR CAR IF YOU'RE GETTING ANY TRANNY FAULTS,
EVEN AFTER RESTART TRANNY ERRORS GO AWAY FOR A WHILE, IT IS NOT A TRANNY
COMPUTER GLITCH!!! http://www.thectsc.com/products/mechatronic-seal-adapter-6hp26-6hp286hp32-42-52.html YES THIS SMALL, CHEAP GASKET CAN DAMAGE YOUR TRANSMISSION
PRETTY BAD. -OTHER 4 RUBBER PIPE SEALS.
They 5,6,7 also control 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 tranny shifts. WWW.RMEUROPEAN.COM has these seals under transmission parts
section. -SOLENOID KITS. 2 TYPES
-MOST COMMON
E65, YOU DON'T NEED PARKING SOLENOIDS SINCE THEY DON'T GO BAD OFTEN, SO YOU
CAN USE M-SHIFT SOLENOIDS, BUT YOU CAN GET E-SHIFT PACK AS WELL, WHICH IS 200$
MORE. http://www.thectsc.com/products/solenoid-kit-6hp19/26/32-m-shift-36-45.html
Yes they go bad and are not simple solenoids you used to
know from old school trannies. Now these are pressure regulators and they do not only work open\close
operation, they control pressure and after so me time they get clogged, overheat, etc. So if your tranny temps
are good and your tranny shifts hard, it could be your solenoids. Its good idea to replace them every 100k,
because they control everything in the tranny. You will be surprised how tranny shifts with new solenoids.
And you don't need 2 parking solenoids, so you can use 200$ cheaper kit, which fits 5,6 series without ESHIFT. Also dont be scared if you open your transmision and find out that color is not the same- relax it
changed color because of temps and age. There are two types of kitsAll the parts at very good prices can be
found here: http://www.thectsc.com/catalog/mechatronic-parts-52.html -GUIBO FLEX DISC. They
usually go bad after BMW lifetime period 60-70k. Common Symptoms: a) hard 2-1 sift b) at stop you can
hear clunking when shifting from P-R-D c)overall tranny shifting quality -Tranny fluid level.
Yes due to leaking oil pan gasket you might loose some fluid.
Always check tranny oil pan for leaks and tranny fluid level (use BMW sealed tranny fluid level check
procedure). It is always better to install metal oil pan- it never leaks and cheaper to maintain! You can add
BMW OEM PENTOSIN brand fluid or you can use MOBIL1 or CASTROL synthetic ATF fluid (10$/qt)
import multi vehicle formula, believe it or not it has same specs if not better than BMW fluid and works
great. Tested for 160kmls. BMW will only recommend OEM FLUID of course, but its up to you, so please
do not comment here that different than OEM fluid will kill the tranny. But always make sure it has the
same specs of course. Mostly Dextron 6 fluid applies as well for this trannies. UPDATE: TRANSMISSION
RUNS MUCH BETTER WITH OEM ZF FLUID OR SHELL M1375.4 FLUIDS, SO BETTER SPEND
FEW MORE BUCKS FOR CORRECT FLUID. FEBI OR ZF WILL WORK GREAT. SOME USE FORD
FLUID, SINCE ITS THE SAME TRANSMISSION BUT FLUID IS MUCH CHEAPER. -Torque
converter clutch.
Yes it can go bad just like any clutch,
because this tranny engages this clutch very early causing premature wear and tear. In sport mode it can
engage clutch as early as at first gear!! That’s why we get decent mpg from this tranny. In other words it is
more like a manual tranny with torque converter working only at very low speeds and low rpm. So I would
not recommend driving it very aggressively in the city, unless you enjoy paying 4-5k for a new tranny.
Don’t forget this tranny handles 300-400hp and some impressive torque. Driving in normal mode, TC can
last up to 300kmls!! most common symptoms of bad clutch: -sometimes when clutch is very bad it will
throw 1721 error clucth slip -bad MPG. Without TC clutch your car is still driveable, but you can feel its
very weak even though engine feels strong -after 4th gear tachometer arrow is not steady -weak pickups,
downshifting when driving uphill -bad slipping clutch will overheat tranny pump and finally will kill
internal tranny parts (clucths, valve body, seals, etc) good news you can have your TC rebuilt for around
300$ and from personal experience i must say its not as perfect as new, but decent still. IMPORTANT
NOTE: DON'T FORGET TO RESET TRANSMISSION ADAPTATIONS AFTER ANY REPAIR
DONE ON THE TRANSMISSION!!! IF YOU DON'T RESET IT, TRANNY WON'T SHIFT ANY
BETTER BECAUSE IT REMEMBERS BAD VALUES. SOME PPL THINK PRESSING GAS
PEDAL AND SAYING SOME MAGIC WORDS RESETS TRANSMISSIONS EGS ADAPTATIONS
IS A TOTAL MADE UP JOKE. YOU CAN ONLY RESET IT WITH BMW SOFTWARE INPA,
ISTA, AND SOME OTHER SOFTWARE SNAP ON ETC. I know its a long list of issues, but if you
take care of your tranny every 80-100kmls it pays for itself pretty good. Most important thing for this tranny
is correct fluid pressure and temps, other parts like clutches are very durable and made with highest quality
standard. Don't forget the same tranny they still install on newest Bentley, Rolls Royce, Audi, Maserati and
other luxury brands. This tranny is way more reliable than Mercedes one or Lexus trannies with same specs.
Great prices on BMW parts you can get from www.rmeuropean.com, they are pretty good and sell only
OEM parts from original suppliers. All transmission parts you can find
here http://www.thectsc.com/catalog/6-speed-parts-113.html
The steel kit will fit the following transmissions:
Trans Type Where used
Main Parts List
6HP26
1068 010 ...
028/054/062/082/083/092/106/125/127/134
151/152/168/171/173/183/185
6HP26X
1068 020 ...
055/070/071/075/078
6HP26-A61 1068 030 ...
024/029/030/033/036/037/038/039/043/044
048/049/056/058/059/060/061/062/063/064
067/068/069/070/072/073/074/075/077
6HP28
1068 040 ...
001/009/010/014/016
6HP28X
1068 050 ...
001/002/007/009/012/013