You really should revive this basic functionality of the transmission. Are you going to worry about this every time you want to service it? That's too annoying. Take a look at this recent thread for some advice on how to remove the plug:
stuck differential plug.
It's not bad at all if you overfill your transmission by about a quart or so. The only downside would be that it will start puking out the vents or through the shifter itself (puke oil past the shift base boot), and it would add unnecessary pressure to the front and rear seals but I don't see it causing any leaks at the seals unless you go waaaaay overfilled. I know a W56 holds about 3 quarts (
from this thread) so the R must hold slightly more. I'd fill through the shifter base and go with the "3+" quarts rating and fill 3 quarts plus half another bottle to be safe. If you are a quart low, or half a quart low, it won't be the end of the world, but just now that some bearings may be a bit starved on oil which will shorten their lifespan. At least winter is right around the corner so the risks of overheating for this year are reduced.
Keep in mind that it's possible they did this for some other reason. They might have accidentally stripped the threads, or they may have over tightened the plug resulting in a small crack at the fill plug flange. I've seen this happen and the result is an eternal seeping leak! So maybe they did that to hide something they don't want you to see. Honestly, stop using SHADE TREE mechanics to work on your precious Toyota truck. People make mistakes but
any reputable shop would 1) NEVER use the incorrect socket size, 2) NEVER use an impact gun to tighten a fill (or drain) plug, and 3) would immediately replace the plug with a new one.
BigMike
