Jeep Cherokee tagged posts

According news from Jeep, they are issuing a transmission control software update for the Jeep Cherokee build before 5/5/2014.

The issue was brought up by the Cherokee owners that complaining jerky transmission operations during driving. The Cherokee’s 9-speed transmission is sourced from ZF. As you may remember from our previous technical analysis of the ZF 9HP transmission, due to how it is designed, the downshift from 8th to 5th, 8th to 4th and from 9th to 5th gears will be quite challenging for this transmission.

While we are not sure the exact details of this software update, it is quite possible that the jerky feeling may be partially contributed by the factor menti...

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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