A common industry procedure when servicing ZF 6HP Automatic Transmission in Land Rover and Range Rover vehicles is to convert the one piece plastic filter pan assembly over for a separate filter and steel pan assembly. The main reason for doing this is ease of re-fitting.
The clearance between the cross member and the one piece plastic pan assembly with integrated filter is too small to allow the pan to be removed without unbolting the mountings, jacking the engine up and disconnecting the exhaust.
Converting to a steel pan with a separate filter allows for easy service and also has the added benefit of being more durable. Consequently, a reduction in future servicing costs is achieved as only a gasket and filter are then required.
Once the transmission has been drained, remove the bolts, and with a hacksaw blade, cut the plastic integrated filter neck as low as possible. Then, slide the old pan out and remove the remaining filter tube from the pump.
The new separate filter can now be installed into the pump, and the steel pan can be slid into place with the gasket in place ready to be bolted up.
A good tip is to run an M6 tap through the case bolt holes to remove any corrosion or debris as the new bolts for the steel pan are longer and have more thread engagement. Always start all the bolts by hand first and then tighten in the correct sequence as shown to 12Nm.