ZF 9HP tagged posts

The ZF 9HP is a 9-speed automatic transmission for transverse engine layout, which is used on the Jeep Cherokee and the upcoming Acura TLX. While there are plenty of technical analysis on this new ZF product, here I am not going to feed you with some PhD-thesis-type content. Instead I have some interesting facts you may find interesting.

First off, don’t be frightened by the below ZF 9HP internal structure image, it is for your reference only, you don’t try and memorize it all in one go. It takes time to learn.

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Last year, Mercedes-Benz debuted its 9 speed transmission (called 9G-Tronic) in its European market E class sedan.

Although with the same aluminum made torque converter bell housing, compared to the current 7G-Tronic, this 9G-Tronic transmission changes to use magnesium alloy to construct its main casing, which is lighter and retains the same strength. The transmission oil pan is made with plastic though.

However, there is no dramatic difference of the mechanical shifting parts between the 9G and 7G transmission. Both of them have 4 planetary gear sets and 6 shifting elements (3 multi-disc clutches and 3 multi-disc brakes)...