Are the washers for the oil drain, tranny drain/fill, and differential drain/fill the same size or do I have to ask Honda for each specific washer?

 

Two of them are the same. I don't remember which ones but you should specify which you need to make sure you get the right ones.

 

Strike is correct, there are several different gaskets for the 5 sealing points (oil drain, transmission drain & fill, and differential drain & fill). The oil drain plug gasket is the same as one of the gaskets on the transmission, but the others are different. I do recall that one of them is copper and all the others are aluminum. They're pretty inexpensive and are worthwhile to replace, especially if you've already reused them once.

When do you know if it's necessary to replace a washer? Some say replace them every time, others reuse them a time or two, but I do know that this one is beyond its service life :

 

Thanks for the replies guys, I might end up just reusing the washers one more time, but not if they look like that! ^^^

 

I re-used them till they start to look like that picture. If you use a torque wrench, you can re-use them a lot. So far, I've only had to replace the fill bolt washer on the diff as this one is impossible to get a torque wrench in there. Also, the fill bolt on the diff takes a different type of washer altogether. It is of some brass or copper construction - unlike all the other washers.