[sanghill]

When you shut off your engine, also, open the driver's door then close the drivers door.
The 'door thing' seems to do more of a reset.
Be sure to keep your AC ON even if you don't need it, helps the drivetrain stay a lot cooler.
Be sure to top up the RDM with the proper gear oil just to make sure it is completely filled. If yours doesn't leak then this will be needed a lot less often.
The goal here is to have the RDM run as cool as possible. There isn't anything you can do to the ATF. Generally I like to engage the rear locker so the ATF does not heat up as much.
I never drive on the Ocean beach just for the issues you mention. Since you probably drive in Ocean water you will probably have a cracked tone ring someday. When it happens you will know it immediately. Jeep will go into 'limp home mode'.
Fun can get expensive. Been there done that, big bucks.
Get your battery tested every couple months, a battery at the 'end of its useful life' will throw a lot of codes. Might even go into 'limp home mode' which would not be pleasant.
Make sure your seat belt is fastened. Jeep operation is a lot more pleasant when you have your seat belt fastened.

 

[sanghill]

This Post should help: Rear axle weep

 

[sanghill]

You can use a pump that screws onto the top of the can. Probably got it from NAPA.

 

[sanghill]

This is available at NAPA: https://www.napaonline.com/en/p/CHT...ShgQE9aq_J-B3viHDMc6uyC2js3O3Vwoxoy2zJLpdS2iuaBxPfo4aAtaFEALw_wcB&gclsrc=aw.ds&
This is for the RDM.

 

[sanghill]

Refer to: Rear Differential chattering, binding, when turning... Post #4.

 

[sanghill]

I vote for a new plug.
I make sure to tighten the bolt just snug enough so I can remove it the next time.

 

[sanghill]

The fill plug has a rubber washer under the head of the bolt, it is part of the bolt.

 

[sanghill]

I am still in favor of my tool in Post #30. It is probably a lot stronger than a 3/8 ratchet, and the correct dimensions since it does not have the ball.
I have a good working relationship with my Jeep dealer, they gladly take my money and do anything I ask.
I would go to the 'quick lube' lane.
For something like the RDM plug, I could just ask them to fill the RDM with oil. I can provide the oil and pump. The chances of them have the pump is probably non existent. Actually, I would more than likely supply the new plug to install.
They WILL figure out a way to remove the plug, no doubts about it. If they mangle the bolt they can supply a new one.
Then, I would ask if I could do the final plug torqueing, that way I will be able to remove it later. I am sure they would go along with this.

 

[sanghill]

The Mopar 1 quart plastic bottle has ounce and Metric markings so you can easily see how much oil was dispensed.
I generally mark the starting fluid level with a marker and then mark it again when I am done. Then do the math. No guessing.

 

[sanghill]

SOP on my TH for the past 9 years.

 

[sanghill]

Refer to Post #64 above to measure how much gear oil was added.