What size Allen Key

[Brightonuk]

Anyone know what dia Allen Wrench is used for the gearbox oil plug on a T-9

Just cut down a 3/8" to a stub and found it is to small?

[11Budlite]

IIRC it should me a 10mm.

[Brightonuk]

Well after looking a little closer and 2 hours of frustration I realize I need a square drive the 12MM hex did not work too big the 10mm hex are to small or a hex will not work with a square hole anyway?

 

I am just stumpt at how to get to this plug out I have less then a 1/2" gap between the plug a a body structural rail situated directly over the plug.

 

I found these an Amazon but I don't know if the 10mm in a square socket will work and as I have to butcher the socket to see if it will even fit I would preferer to get the correct size to begin with.

 

https://www.amazon.com/CTA-Tools-2049-Square-Sockets/dp/B008TOHAVG/ref=asc_df_B008TOHAVG/?tag=hyprod-20&linkCode=df0&hvadid=312540934012&hvpos=&hvnetw=g&hvrand=3825463004270120153&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9011978&hvtargid=pla-641879711752&psc=1

 

Any pointers would be greatly appreciated. 

[Brightonuk]

Change of Plans get a metal bar from the depot 3/8" and 1/2" dia cut that down to a nub and see if one fits?

[JohnCh]

There is a chance that plugs used in Type-9s vary.  I'm pretty sure mine is a 10mm hex.  Have you tried getting an outline of the plug top by pressing clay or a piece of paper against it?  Fingers work too if you press hard enough.  Just make sure you measure it before the outline fades from the skin. 

 

-John

[papak]

I know mine was a 10mm hex. It's a common VW tool. Mine is probably 50 years old from my FV days.

[Nick OTeen]

11 hours ago, Brightonuk said:

Well after looking a little closer and 2 hours of frustration I realize I need a square drive the 12MM hex did not work too big the 10mm hex are to small or a hex will not work with a square hole anyway? 

 

To answer your question, no, a hex bit (or Allen key) will not be suitable for removing a drain plug that has a square opening.

 

While the standard drain plug on a T-9 transmission can be removed/installed with a 10mm hex tool, there is always the possibility that your plug got switched out some time in the past for a plug with a square opening. As such, you might try simply using a socket wrench with a 3/8" drive extension to remove the plug.

Edited March 11, 2021 by Nick OTeen

[Brightonuk]

That would work perfectly if I had enough room to fit the socket wrench (assuming the 3/8" would work) between the plug and the body but as I pointed out I have less than 1/2" to play with.

 

 

 

I think cutting square rod to fit the plug opening and then an open ended spanner to turn the rod seems like the only way left to try, or just leave it be and assume that I don't really need to do this  

 

[wemtd]

Check your footwell wall. 
my car has a access hole you can insert a driver through to reach the gearbox fill hole

[Brightonuk]

The issue for me is a part of the cassis framework in located directly over the plug otherwise I would have room to use a ratchet 

 

[JohnCh]

It's hard to state if this would work from the picture, but if I was committed to removing the plug with the transmission still in the car, I'd be tempted to do the following:

• Cut access hole, sized to accept an off-the-shelf plastic or rubber plug, as close as possible to the frame tube
• Get square stock the appropriate size, then using a grinder, create a ball end that will allow you to insert it into the plug at an angle.  Something like this hex key

 

Assuming that works, you may still struggle to remove the plug in the available space.  I don't recall the length of the plug, but even if it is shorter than the gap, it may need to be loose enough at some point that you can unscrew the last bit with your fingers grasping the exposed threads.  

 

Do you know how long it's been since the fluid was changed or the engine/trans was out of the car?  

 

-John

[JohnCh]

Just had another thought.  It's not clear from the photo how the frame tube is positioned over the plug in the vertical plane.  Is it possible to disconnect the engine and transmission mounts and lower or raise the engine trans assembly just a bit so that the tube is no longer directly over the plug?

 

-John

[Brightonuk]

Possible

Another posable option by removing this top plate from the top of the trans will it give me access to refill the oil?

 

 

[Anker]

I have wondered about that myself. It will work really well of the fill plug hole is visible from above. Then it will be easy to fill to the bottom of the plug.

[JohnCh]

I remember reading a write up about this many years ago.  As I recall the person welded a bung on the front corner of the cover plate and added a threaded dipstick.  If you have room to remove the cover plate, that's certainly an option.  You may need to order a replacement gasket and scrape off old sealant though.

 

-John

[Brightonuk]

John so removing the cover plate will gain access to where I can drain/add the gear oil oil as this is a hell of a lot easer than trying to get to the plug 

And if so it may be difficult to judge the oil level what is the fill rate on the T-9 1.9Ltrs?

 

http://www.madabout-kitcars.com/kitcar/kb.php?aid=160

[JohnCh]

The fluid level changed in the later boxes to 1.6L.  As I recall that was to reduce frothing so early boxes can also run that amount, but someone here may be able to provide a definitive answer.  Given you are unlikely to remove all the old oil (the case is packed with gears, so I wouldn't rely on being able to see the bottom) I would get a piece of wire, run it outside the box to the bottom of the fill hole to get a measurement to the top of the case.  Then get a longer piece of wire to use as a temporary dipstick and use the measurement from the first wire to mark a full line.  

 

Before you undertake this, I would be certain you have sufficient room to maneuver down there. 

 

-John

[Brightonuk]

KK thank for all the advice will let you guys know how it turns out once the second ltr of oil turns up (Saturday)

The gasket is another story, looks like my best option is to fabricate one as I cant find just the lid gasket

 

Lastly is this screw securing the lid (there is only one)

I have not seen this style before  if it does need to be removed what tool do I need 

 

 

 

 

 

 

?

[coffee break]

Looks like a rivet of some sort.

[JohnCh]

We uploaded several Type-9 documents, including a service manual.  Take a look through those to see if you can make sense of it.  I "think" it may simply be a riveted locating pin.

 

https://usa7s.net/ips/files/category/31-gearbox/

 

-John