L322 Supercharged Gearbox

Finally managed to convince the wife we really needed a Range Rover again last Summer and found a great 4.2 Supercharged Vogue SE which apart from having a drink problem round town, has been the most fantastic vehicle and we've put 15k miles on it around France, Devon and Cornwall. It's always had a few minor gearchange issues with the occasional harsh change especially when kicking down (thumping) and a bit of a clunk when coming to a stop but 95% of the time smooth and lovely.
However, the last couple of days when cold it's been horrible, reluctant to go into 2nd without flaring and a quite a disturbing bang/shudder when kicking down, it improves considerably when warm though.
I had the codes read by a local guy who MOT'd it today and apparently the code displayed indicated the clutch pack was failing/slipping (forgot to write the code down)
Had a phone quote for £1700 to get my gearbox reconditioned which I'm ok with but after doing some internet searching I'm wondering whether it would be worth getting the gearbox ecu flashed with the latest software before I shell out. The gearbox has done 120k miles now and with best part of 400 bhp going through it was never going to last forever. Would I have to go to a dealer to get the latest gearbox update or is it available else ware? Any advice greatly received.

The ZF 6HP26 transmission is recognized as being mechanically pretty bullet proof with very few mechanical issues flagged since it started in production 15 years ago. Some models had an inferior material used for the rear stator bush which subsequently wears and causes the E clutch to leak pressure but, apart from that, only the durability of the EDS solenoids let it down. These solenoids are responsible for the vast, vast majority of issues with the 6HP26.

The 1-2 and 2-1 shift thump was dealt with by fluid changes and firmware updates (the adaptions didn’t change in the way ZF had expected them to, so had to correct this) and of course there’s the ‘cable clamp bolt rusted into the selector lever’ issue which occasionally occurs, causing the transmission to drop into neutral when accelerating etc.

One other point is never to reset the adaptions just for the sake of it when the fluid has just been changed. This can lead to the clutches burning out as the Mechatronic unit tries to reset the correct clutch pressures but doesn’t get there in time.

I would definitely recommend that you get the Mechatronic unit checked out on a Hydra-Test machine before assuming that you have a mechanical issue with your transmission.

https://xoutpost.com/907717-post1.html

Phil

Bemble, Many thanks for your reply. I will make arrangements to get a Hydra Test done. Can it be done with the gearbox in or will it need to be removed? Any idea what kind of cost would be incurred and should any auto specialist be able to carry it out?
Thanks Again

There’s no need to remove the transmission from the vehicle. You just need to drop the Mechatronic unit out of the sump. A Hydra-Test machine is a specialist piece of test equipment for automatic transmission valve body assemblies.



I use this place on the Wirral to test mine : http://www.valvebodyuk.co.uk but other places have these machines too, like STA at Aylesbury for example. It should cost around £60 for the test.

https://youtu.be/FU3KvO8zKlc

Phil