I know I am new here but I am not new to rear axles. This is my first post and I am only here to provite tech support since, as far as I know, no one has done a gear change and a Quaif install into one of these cars. Enjoy the pics and feel free to add any information you might have.

I have recently done a gear and differential change on a 2007 Dodge Charger SRT IRS center section. I believe this to be the same as the Chrysler 300M's but don't quote me on that. Pics are included and this was not an easy change and it required some specialized tools.
As we can see here the rear cover is attached by torx bolts that require a torx socket.

These seals need to be removed without being damaged and reused. This IRS is from Germany so getting parts will take a considerable amount of time.

Other side,

This is the pinion flange and as you can see it is not like a conventional flange. The pinion nut required a special size metric socket.

Once the cover has been removed you will notice there are no main caps.

Behind the seals the differential is held in by snap rings. Make sure to mark each ring as they are different thickness's from left to right. They are not easily removed, the carrier is preloaded by these as well.


The differential with ring gear will need to be removed from the passenger side, the differential case is elongated so you can maneuver it out.

Once fully disassembled you will notice the pinion is not preloaded by a crush sleeve. It uses hard shims, the pinion depth shims are located behind the pinion bearing race in the housing. We installed a Richmond 3.55 ratio and a Quaif differential. The pinion needed to be moved deeper about .004 and once we had it installed we had to swap the differential snap ringsa to get the correct backlash setting.

Again, this was not and easy install and if anyone has any questions please feel free to ask away.
Scott @ DLS