16/01/2022
Hi Guy's, finally some time again to post something about our Range Rover gearboxes and this time the ZF6HP26.
Basically I start with stripping the gearbox and clean all parts from debris to get a proper view on the status of the gearbox.
Specially on this model gearbox are the bushes very important and can be worn out extremely overtime depending on the driving behaviours and service intervals.
I know the storey that they are sealed for lifetime what isn't true!
Everything what get lubricated by oil needs at some point new oil and for this gearbox is 80K miles a good starting point to do a first gearbox service.
It makes sense with a fresh oil and new filter the lubrication is much better and your gearbox will last longer but there will be a time that critical parts get worn and start giving symptoms of bad shifting or slip.
The stator bush in this gearbox is very sensitive and when it get worn out the E-clutch will not get the oil pressure any more to engage.
This bush will worn out faster with old oil and bad driving behaviours.
Bad driving behaviours are when you don't give the gearbox time to warm up same like as for an engine. Or when you start the car and don't give the gearbox some time to lubricate before you drive away because the system inside has to fill up again.
These rules are important to follow to give the best treatment to your gearbox.
The valve body is another thing which is very important and manage smooth shifting between gears.
Sometimes a lot of debris can be collected in the small channels which you never can get out then to open the valve body.
Also a Mega Flush what people let do will not get this debris removed.
Opening of the valve body means I need to fit a new middle plate and also the accumulators can be so flat that the function of these is reduced to zero. Normally they work as a kind of little shock absorbers when line pressure change during shifting.
See the photo of an old and new damper.
Solenoids are a very expensive parts of the gearbox and sometimes good to change preventively.
It's very random and many time they last forever unless you have bad shifting experience.
The mechatronic is the computer bit in this gearbox which I always will swap over to the rebuild gearbox because it's programmed to the BCEM with the details of the Range Rover.
Some in the first Range Rovers with this gearbox are compatible!!!
Overhaul a very good gearbox and with a good service and attention capable to do a good job in the Range Rover 2.7 TDV6, 3,6 TDV8 and the V8 SuperCharger.
Any advise needed please feel free to contact me.
