What size tool needed on 530 to fill tranny?

[barry 90 525i]

Wanted to check my tranny fluid, saw what looked to be a big hex key insert. What size will i need to buy or is a different tool. Bentley does not give any ref for tool. also is the small drain plug anything special? thank you

[bubba966]

If it's the same as the plug on my 540 pan it's a 17mm hex as I recall. Sears carries that size in both a key and a socket, though the socket isn't as commonly stocked as the key is. And best thing about Sears is their return policy should it be the wrong one. Pretty sure it's 17mm, though it's been a while since I bought mine.

[632 Regal]

naw your right 17mm I just went to a used tool place and cut a big ass allen wrench down and use a socket with it. 4 bux better than the ~20ish they wanted for a "tool"

[philbyil]

On my 1995 Getrag SZ250, its a 17mm socket!
One quick tip for a drain and refill. Buy about 5foot of 1/2"" ID clear plastic tubing, run it down from your engine compartment to the gearbox. Then, after draining your gearbox and using a small funnel, run the tubing into the level/fill hole and run your gearbox oil down it until you hear it trickling into your drain pan. Remove the tubing, tighten up your fill plug and Voila!

Just did that on my 525i manual.....makes it a doddle !