Yes, that is the dust cover portion of the universal rear yoke.
The seal is under that.
Full repair instructions are in the FSM (Factory Service Manual) section #3
Special tools are required, not for the faint of heart!
You will need a hefty wrench and socket to remove the yoke (it is torqued to 240 ft lbs!) from the pinion a drive shaft wrench to hold the yoke while doing so plus a puller to pull the seal from the case.
Then a heavy-duty torque wrench for reassembly.
IMHO, this job is best left to a shop equipped with the proper tools and know how to handle the task.
But then.....I'm not a spring chicken any more.
Good luck
From: "John Gaynor" <gaynorindustries@xxxxxxxxx>
To: "finsruskw" <finsruskw@xxxxxxxxxxxxxxx>
Sent: Thursday, March 27, 2025 11:06:41 AM
Subject: Re: {Chrysler 300} Pinion seal
Interesting
That's the one that is too small. Am I measuring a dust cover and not the seal? I'm measuring 3.5 inches and seal is 3.1. It's not apart yet.
First time doing a pinion seal.
John
On Thu, Mar 27, 2025 at 11:34 AM, Finsruskw@xxxxxxxxxxxxxxx
<finsruskw@xxxxxxxxxxxxxxx> wrote:
OEM Chrysler Part #1828-719
NAPA 49230
Ask them to run those numbers and you should come up with a winner.
From: "Chrysler 300 Club International" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
To: "Chrysler 300 Club International" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Sent: Thursday, March 27, 2025 9:26:16 AM
Subject: {Chrysler 300} Pinion seal