I recently purchased our first L322 – a Tonga green, 2008, 3.6 TDV8 with 185k on the clock. The gearbox has the classic “cattle grid shudder” which is most prevalent whilst driving up a hill. It also has a tendency to hold onto gears and not shift on time (often revving to 4k RPM. This was remedied by knocking the gear selector to the side and controlling the gears manually.

Over the weekend I set about removing the old lump from the car and now have it laying on the garage floor. I have purchased a second-hand gearbox from a salvage vehicle that has done 125k miles and will sent the torque converter off to Sussex autos for a rebuild. Before installing the new gearbox and torque converter, are there any suggested weak points / serviceable items that I should tackle whilst the box is out?

Is it also advisable to swap the original TCU into the new box to save coding once it goes back in or is the coding straight forward with Gap IID?

Finally, is there a more affordable, suitable transmission fluid or should I stick with the ZF?

(Should I add shudderfix as preventative maintenance or is this just a solution to eek out a few more miles once it’s on its last legs?

Apologies for the lengthy post, any advice is greatly appreciated and I’m excited to finally start enjoying my l322 ownership!