Timm's BMW E63 and E64 Harsh Gear Changes
Especially under acceleration and in Sport Mode
This was the first 6-Series I test drove in 2013 - and I would have bought it except the gear changes were poor - I really didn't want to
take on a car with gearbox problems even though it was a facelift and going for a good price. But, having had a 740i with a dodgy torque-
converter for years I really didn't want to have to 'drive around' the harsh changes. Shame, it was a great car.
It was a while before I drove another one - and the same thing happened again on another facelift, and again on a pre-facelift model.
Fast forward a year or so and I am the owner of my 650i - and that has better changes, but they certainly aren't perfect, especially the change
from 5th gear to 6th gear when under a bit of power - my plan was to change the MAF to start with as this can be a cause of heavy changes
on earlier models such as the E31 840ci and the E38 740i - but, it didn't make a jot of difference (at least the MAF was cheap).
I was lucky to have a friend (Rupe) who had just bought a 650i with poor gear changes and he is a lot less lazy than I am. He did a number of
jobs that I should have done - plugs, coils, MAF and finally an ATF and filter change. Each job made a small difference, but the job that fixed
the problem was resetting the gearbox adaptations.
Gearbox adaptations (on the previous generation 5HPxx gearboxes) are usually only done if something within the gearbox has changed (such
as a pressure-control valve or a clutch pack) - so it is rarely done, and it usually makes absolutely no difference at all. But, on the 6-speed ZF
gearboxes as fitted to the E63 and E64, resetting the gearbox makes a huge difference.
And I do mean a HUGE difference, the gearbox is now so smooth that you really only notice the gear changes by the slight drop in power just
before the change is made. Under acceleration the 5th to 6th gear change is great, no thump at last. Below is a sequence of screenshots that
show how to reset the adaptations with INPA - unfortunately I’ve missed one between the first and second which is Activate
I bought the software from Amazon along with the lead to connect the car to a Laptop for around £40 or so, usually less. I would guess that a
BMW dealer would not do this for you - but it is worth asking
If this routine does not get you back to smooth changes then it is time to change the transmission fluid, the gearbox filter and two seals
within the gearbox. Fortunately both seals are easy to get to during the fluid and filter change. The only additional stage is that the
Mechatronik unit is dropped from the valve body to get access. Both of these parts are shown in the routine shown below in steps 4 and 7:
Mechatronix Mechanism Replacement
Although the gearbox is ‘filled for life’, by 100,000 miles the transmission fluid has lost its tightly-controlled friction properties. Unlike the
5HP24 gearboxes that don’t let you know until they actually fail, the 6HP26 starts clouting through the gears - but, they have an excellent
reliability record so don’t panic!
All done, time for a cup of tea
