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Plug sizes

drooartz

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Couple of questions on drain plug sizes. On a smooth case transmission (at least mine) the drain plug and the fill/check plug seem to be the same size. I used a 3/4" socket, as it seemed to fit the best, but seemed a bit loose. What size is this really?

On a related note, the rear diff has 2 recessed square drive plugs. What size are these? I need to D&R the rear as well, and don't seem to have the right size square drive. Seems larger than 3/8", smaller than 1/2".
 
Is it possible that those are whitworth?

Drain plug on the diff is about 1/2" and tapers to about 3/8".
I'm told that wrenches to fit these are available the usual tool sources. I've never looked. You may be able to create your own with a little creativity and a file. I think we discussed this recently here.
 
The plugs on the tranny are 11/16 (wrench size)
To remove the plugs on the diff, just use a 3/8 ratchet wrench with nothing on it. It's a bit loose but it works fine if no one muscled it in the past.
 
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