FWIW, my 6HP26Z in the 4.8is was exhibiting bad 2-1 downshift kick (the infamous being rear ended feeling) for a long time. I learned to drive around it and thus avoided it 99% of the time.

Anyway, I used the Valvoline Maxlife ATF Full Syth multi vehicle, paired with bridge and tube seals, followed by a adaptation reset @ ~120k miles if memory serves. Trans has been perfect for 3 years and 10k miles. Having experience with most of the fluids ppl use in ZF transmissions... the Valvoline is my favorite (the thickest). I've used Pentosyn, Lubri Moly, Red Line, and of course Lifeguard 6 (the thinnest).

BTW, I have 7L (I think, maybe 6) of ZF LG6 here that I'd let go for cheap if anyone local was interested. I'll never use it.

Sorry for the slow response - lots of life admin needed lately...

It's not a hard job to replace the seals BUT you do have to drop the entire mechatronic assembly from the transmission, so you need to have your wits about you... and you'll need a 1/4" drive torque wrench to remount the mechatronic.

There are four "jump" seals and one "bridge" seal, as well as the main mechatronic sleeve that seals the transmission connector.

https://i.ibb.co/zSk8J7L/20210118-212521.jpg

There are tons of videos and guides online on how to do this, along with the ZF guides online also.

And since the ZF 6HP26 was also used in the Ford Falcon and Territory, there are lots of ZF parts suppliers in Aussie, like...

https://www.damet.com.au/services/zf-australia/

Hi Wayne, Why did you decide to change the seals in the transmission, was your car doing anything to prompt you to do this? Any codes thrown?

I am asking because the issue I was having which felt like a misfire when cruising at around 110km is more likely to be the transmission hunting between 5 & 6th. I have also notified the car is slow to engage reverse after its been sitting a while. The 6HP26X filter and fluids were changed 40K km ago and this issue only started about 10k km ago. Its more of a occasional annoyance as the car hasn't ever gone into limp mode, it occasionally throws a 4F86 or 4F80 Ratio Monitoring Error.

Did replacing the seals fix your issues?

Cheers
Chris 2005 X5 3.0D 334K km in Oz

I had a slight leak on the mechatronic seal and since I was opening it up to sort that, I figured I would replace the jump seals and bridge seal too. As you do. No other reason, other than the hope of extending the life of the transmission.

I have some slightly odd behaviour from my trans - it's certainly not perfect but its still pretty good for a trans with over 280,000kms. The hard 2-1 shift has recently become more obvious, it holds second gear way too long and it does seem to hunt a little between 4-5 at low rpm when cold (changes up too soon and engine lacks the torque - so turbo issue?) - might need to sort that soon, although I have yet to decide how I might do that! :rolleyes:

But on the whole, it still drives very well and I'm still very happy with it.

I doubt replacing just the seals will fix your issues. I hear that these trans can suffer loss of solenoid performance and respond well to solenoid replacement but I'm not sure of the exact issues at play here.

I sometimes get that kick in the butt especially going uphill and stopping, and then when taking off the car gets kicked in the butt real hard :D. Trans service has been in my to-do list for years. I got all the parts except the trans fluid, just the time that is elusive :D. I did the same service on my E92 years ago with great results (reverse gear would slip occasionally).

A note to say that Wayne and I both ran into a problem with the bridge seal (leftmost one in his picture). The ones we received had two tabs that made it so they wouldn't fit into our earlier revisions of the transmission. See this post and its thread for details:

https://xoutpost.com/1232995-post6.html