Transmission drain

[RJT79]

So I have a transmission fluid leak on my tii.  Took a picture of the transmission drain and all I see is thread but not a bolt.  Am I missing the plug completely?  

[Mike Self]

It uses an Allen head drain plug--I looked but can't find the size of the Allen key needed.  I want to say 10mm but that may not be correct.  

 

Before removing the drain plug, make sure you can remove the filler plug!  You'd feel pretty dumb with a drained tranny and no way to fill with new fluid!

 

mike

['76mintgrün'02]

It's 17mm, or 11/16" will do.  Here's a neat old VW wrench I found at the habitat store a while back.  

 

I've got a big 11/16" Allen wrench that has been getting shorter over the years, as I've cut pieces off to use with a socket, or a wrench for the fill plug.

 

Tom

[RJT79]

Thank you both for the help.  My question is if the plug is the right size, how does it start leaking?  

[Mike Self]

1 hour ago, RJT79 said:

if the plug is the right size, how does it start leaking?  

Steel plug and aluminum threads:  different wear rates, different expansion rates.  Folks in the past have used Teflon plumbers tape around the threads; that seems to work presuming the threads themselves aren't damaged.

 

And there may supposed to be a copper crush washer under the drain plug.  It's been awhile since I had one out, but I know the oil drain plug has one...

 

mike 

[tech71]

15 hours ago, RJT79 said:

 Am I missing the plug completely?

If that was the case your gearbox would have let you know by now.

Fist thing to do is check and see if the plug is loose/ needs tightening

[Einspritz]

The plugs are a taper thread

[TobyB]

Don't go berzerk with the teflon and the tightening-

it's a taper thread, and lubed with the long- chain polymers,

it can split the case.

 

It's rather likely that it's leaking higher up, and you're just seeing the

end of the trail.  The plugs do sometimes leak, but you'll need to jack the car

crawl under it and really check things like the shift rod seal, platform bolts, etc

to confirm it's the plug.

 

And then yeah, a few wraps of teflon and an EASY tighten usually does the deal.

 

t

 

[SydneyTii]

On 5/27/2023 at 3:01 PM, Mike Self said:

Before removing the drain plug, make sure you can remove the filler plug!  You'd feel pretty dumb with a drained tranny and no way to fill with new fluid!

Yep! Bloody thing…. Got mine undone fortunately, but I will never make that school boy error again🙄