Crush washers?
 

Are the Gear box and diff crush washers the same part as the engine sump plug. I`m about to change the fluids and I have 1/2 a dozen engine washers. I wont buy new ones if they fit.

The diff and trans are the same size - 18mm x 24mm. I have a Fumoto drain valve and have forgotten the thread size, but I'm 99% sure it's not 18mm.

I picked up a selection of copper sealing washers from Amazon and used 4 of them - 1 for each drain and fill. The copper washers are potentially reuseable but they're cheap enough that I don't plan to. If you decided to reuse remember that copper work hardens and will need periodic annealing.

When I went to the dealer I ended up getting two different sets of washers for the trans and diff. They looked similar, but we're different part number.

Thanks Guys. I just measured the Engine sump washer and its Approximately 20 x 26. Copper is good and just heat to a glow and cool for annealing.