Tranny leaking from small plug next to tailshaft

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1fine69

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Anyone know what size the small plug is on the 727 tranny on the aft right side next to the tail shaft? Looks like someone put RTV in there instead of the plug!
 
By your description that sounds like the rear servo test port but that is under over 200 psi of pressure when in reverse so if it were just filled with RTV it'd blow out immediately when you put the car in reverse. Can you post a picture of the plug to verify what your talking about? if it is the test port it's 1/8" NPT
 
Probably the rear servo anchor pin that's been attempted to be sealed up from the outside.
 
You are correct sir. I will be taking it back to the tranny shop for this one. After all I paid good money to have it overhauled!
 
1fine69 said:
You are correct sir. I will be taking it back to the tranny shop for this one. After all I paid good money to have it overhauled!
Click to expand...

In order to do that pin correctly the extension housing, pan and rear servo lever have to come out.
There is an O ring groove in the pin, and some just try to seal it without pulling it out, so if they don't pull the pan and rear housing they are not doing it right.
 
1fine69 said:
You are correct sir. I will be taking it back to the tranny shop for this one. After all I paid good money to have it overhauled!
Click to expand...

In order to do that pin correctly the extension housing, pan, valve body and rear servo lever have to come out. (it can be done without pulling the valve body, but not by many)
There is an O ring groove in the pin, and some just try to seal it without pulling it out, so if they don't pull the pan and rear housing they are not doing it right.

Here's the pin O ring in the first pic and where the pin sits in the trans in the second pic.
 

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I cleaned mine up real good and put blue Pematex in that hole. It was just seeping a little. It has not leaked for 5 years with the Permatex.
 
I've noticed some shops put RTV there even when they replace the o-ring. I guess they do it for extra protection against a leak.
 
1fine69 said:
Will I have to drain the fluid first before I can use the permatex?
Click to expand...

If you just want to seal it from the outside you will need to spray it well with carb or brake cleaner and alternate a couple of times with air if you can to get it dry of fluid so the Permatex will stick well.

I would also press the Permatex in with a finger to get it down in the gap as much as possible.
Then you can wipe off the extra and let it set up.
Should be fine after that.

No draining of any fluid needed, but you might want to run it in neutral for 30 seconds before you start on it to get the fluid level down to normal.
If you do it cold without a startup, the fluid level may be pretty high and just re wet the surfaces you want nice and oil free.
 
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