Continued to work my way down the drive train.  Popped the rear cover off the differential.

• The good news is that the differential contained the correct amount of oil.  Maybe I should say oil and sludge.
• The Plymouth Instruction Book for the 29 U had no recommendations for cleaning this area but I felt after 78 years that maybe it was about time.
• The oil was black and had the consistency of molasses.  The amount of sludge was incredible and needed to be spooned out of the bottom of the differential casing.

• The gears look great with no noticeable wear or problems.

• The plan here is to clean up this area as well as possible then reinstall the rear cover and fill the differential with kerosene and run the car on the jack stands in third gear for a couple of minutes to give the differential assembly a good wash.

• It always gives me pause to think about what might crop up after you remove the protective coating of dirt and sludge but deep down I know it is the right thing to do.

• As an aside I also have one more wheel to complete the brake job.  The rear seals do not appear to be leaking so I will let this go until I have the brake shoes relined.  Right now I still have plenty of meat on the old shoes.  Once the rear-end is completed I will drop the oil pan and go after whatever awaits me in that area.