Incredibly dumb differential oil change questions

So I am having the old rear gear and locker thing done at ECGS and at 500 miles I will have to replace my rear diff fluid. It has been 15 years since I did this and that was a Jeep.

I have watched some videos and it *seems* pretty easy. However, I am a little unclear after watching the videos about the washers and fill amount.

1. Some videos have links to two different washers. For example one video linked to these

15pcs Front & Rear Differential Oil Drain Plug Washer Gasket Seal – 24mm Replacement for Toyota/Lexus - OEM 90430-24003 90430-24017 4Runner Land Cruiser Sequoia Tacoma Tundra 1995-2022 by AUTOMAJOR

https://www.amazon.com/dp/B09SLZQ5QH/?coliid=I3SHDDJYM38O83&colid=6QWZTAZD5F4P&th=1
and these

10 Pcs Front and Rear Differential Fill and Drain Plug Crush Washers Gasket Compatible with 4Runner T undra T acoma S ienna FJ Cruiser Land Cruiser, Replacement for The Part# 12157-10010

https://www.amazon.com/gp/product/B07DFK1XWD?ie=UTF8

I assume you only need one washer on each plug, correct? Any preferences between these two?

2. All the videos show the person putting a new washer on the drain plug. I assume I should put one on the fill plug as well?

3. The internal free space in my rear diff is about to change with the addition of the lockers...should I just fill until the oil is spilling out of the fill plug hole?

Thanks in advance

 

I have used these for many diff changes. Check your manual for how much oil you need depending on what model you have.

for the first change to allow break-in use 85w-140 (which is what ECGS will recommend). After that on your next Chang you can use the standard 75w-90 or if you tow 75w-110 (rear diff) and 75w-90 (front diff)

fill until starting to drip out. Super easy

$6 Rexka 12pcs Transfer & Differential Service Gasket Kit Compatible with Toyota Lexus 4Runner Land Cruiser Tundra Tacoma FJ Cruiser Highlander RAV4 Sequoia Sienna 1215710010 9043024003 90430A0003

https://www.amazon.com/Rexka-Differ...37------------&vehicleName=2016+Toyota+Tacoma

 

1) The Brass/Copper Washer is for the Front Diff Drain Plug. The other 3 Diff Plugs all use the same Crush Washer. Yes, there is only one washer per plug.
Just go the your local Toyota Dealer and tell them which washers you need, and you will then get the correct ones.

2) Yes, if you take out a plug (fill or drain) you should replace the washer with a new one.

3) Fill the Diff until it flows back out of the Fill Hole - that is how you know that it is properly full.

Most Importantly: Always make sure that you can get the Fill Plug loose & removed before you remove the Drain Plug.

It's an easy project, have fun doing good things for your truck

 

Idk how the washers on these tacoma's are, but when i had my tundra i changed the gear oil's a number of times in that truck. Never once did i have to use a new washer. I never had a leak either in 19 years. I would just torque those plugs to spec.

 

Definitely. In my Jeep days I knew someone who did the drain first and then couldn't get the fill off. My friend who is a mechanic used a crazy tool that wrecked the fill bolt/plug to get it off, but it was getting scary in terms of whether we could get it off.

 

Pro tip on the front diff drain plug: give it a good whack with a hammer before you start wrenching on it. Mine wouldn't break loose and I nearly stripped the Allen head until someone suggested hitting it.

Some folks like the lexus plug better than the Allen head that comes stock. Not necessary, but something to consider:

https://www.tacomaworld.com/threads/front-diff-drain-plug-alternate-oem-part.604989/#post-20391465

 

Its good to know that. That said, I would be very surprised if it wont come off since ECGS would have just put it on a couple of weeks earlier