Draining the transmission on an MK1

[ORCoaster]

What am I thinking that is wrong here?  I want to check fluid level and quality on my Caddy with an 020 FF transmission. Bentley's manual shows the drain and fill holes but doesn't say the size.  I thought they were 17 mm. 

Is that not correct?  I can't seem to fit my 17 mm hex for my 3/8ths inch drive in the space provided.

What tool do you use to get those out?

I may be looking at some nuts and a bolt to put up in there and turn it with a socket instead of the breaker bar.

Awaiting answers.

Thanks.

[rabbitman]

Mine are 17mm, maybe yours took a hit and messed up the hole. That's odd

[Rabbit79]

17 mm Allen is what mine is. I guess the in vogue thing is to call it a hex key nowadays, but I still call them Allen wrenches.

[ORCoaster]

I thought it may have taken a bump and so I ran my finger along the edges and even tried a flat-file in there.  No joy and I tried to hammer my big Allen wrench in there and it was denied. 

I think I have some 16 MM nuts and a bolt hanging around here somewhere.  I may see if those go in the plug.  If so I may invest in a 16 MM hex head on a 3/8ths inch drive.  Very odd as my Rabbit uses the 17 mm ones no problem. 

Maybe someone swapped the transmission somewhere along the line and bought non-stock plugs for it.  Sure a pain in the shoulder to get under there.

[fatmobile]

 A 5/8" bolt head is the same as 16mm.
 That's weird that a 17mm allen wrench won't fit.
 A lug bolt is the usual goto.

[ORCoaster]

Thanks for the conversions and another use for a Lug bolt.  I keep several of them in the ammo box with the hydraulic jack in the Caddy.  I had walking bolts for a little while and I needed to have spares on hand, or on the road rather.