Short answer
ZF Friedrichshafen approves lubricants for its transmissions and axles through numbered “TE-ML” lubricant lists, each covering a type of ZF component, with letter suffixes for different oil classes and drain intervals. Approval is granted to named products and published by ZF. A label listing a TE-ML number is only an approval if the product appears on ZF’s current list.
How the TE-ML system is organized
ZF builds manual, automated and automatic transmissions, axles and other driveline components for trucks, buses, off-highway machines, marine and other uses. Instead of one fluid specification, ZF publishes a set of lubricant lists numbered TE-ML 01 onward. Each list applies to a family of components, and within a list, letter classes such as 14A or 14B separate oils by type and permitted change interval.
Examples include TE-ML 02, which covers manual and automated transmissions in commercial vehicles; TE-ML 05, which covers axles and differentials; TE-ML 14, which covers powershift automatic transmissions in buses, coaches and heavy trucks; and TE-ML 20, which ZF uses for its EcoLife-type powershift transmissions.
Classes and drain intervals
The letter class matters as much as the list number. Within TE-ML 14, for example, ZF uses different classes for fluids approved for conventional intervals and for longer intervals. ZF’s list also sets rules for switching between classes, such as requiring an intermediate drain when moving to a longer-interval fluid.
Because those rules change between editions, the edition date on ZF’s published list is important. A newer edition supersedes earlier ones.
Approval is by product name
ZF lists approved lubricants by brand and product name. A fluid that says it is “suitable for ZF TE-ML 14” is not the same as a fluid ZF has listed. If a warranty or service contract requires ZF-approved fluid, check the current list on ZF’s website.
Finding the right list for your equipment
The ZF type plate on the transmission or axle and the vehicle builder’s manual identify the component and the required TE-ML list and class. Vehicle builders sometimes have their own requirements on top of ZF’s.
Once you know the list and class, confirm against ZF’s current edition and the product’s current data sheet before ordering.
Frequently asked questions
What does TE-ML stand for?
It is ZF’s designation for its technical lubricant lists. Each numbered list covers a type of ZF component.
Where do I find ZF-approved lubricants?
ZF publishes its TE-ML lists, with approved products by name, on its aftermarket website. Check the edition date.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].