So few questions I have a 93 Ford f150 long bed regular cab rear wheel drive with aod transmission solid one piece aluminum drive shaft I have a severe leak I have narrowed it down I believe to my dipstick tube coming into the transmission pan however I'm confused as to what a part on the transmission itself is it is on top of the transmission centered just before the transmission extension housing and it seems like it's a pressure relief valve or something the only thing I can find online as far as a part number it labels it as part 410 but when I look up that part number on other websites it tells me it's a neutral switch I don't see or feel any electrical connectors going to it I'll see if I can get a picture of it and upload with this post but if somebody can please tell me exactly what this is I would greatly appreciate it also on the offshoot that it's not just the dipstick grommet that's leaking I'm also going to replace the TV rod / TV cable input there's two gaskets there one on the inside and the one on the outer side what else is problematic with these transmissions for leaking the cooling lines look good with no leaks nor does the threads where they attach the transmission look like they have any leaks any ideas thoughts helpful tips or tricks are greatly appreciated thank you guys and before I forget it's definitely not the pan I pulled it off twice thinking that it was cleaned it up real good put RTF on it it's definitely not leaking at the pan.

 

Your picture is useless. You need to completely wash down the transmission to find the exact source of the leak. I have had several AOD transmissions. The only places I had leaks were the pan and rear tailshaft seal. They are very reliable and robust, especially the hydraulic controlled ones prior to 92.. Don't mess with the TV linkage and do not use RTV at all as a substitute for a gasket.. The tailshaft area also has the speed sensor for the speedometer. The biggest problem you need to watch out for is the plastic bushing retainer at the throttle body.If it pops off (which is common) while you are heavily accelerating, bye bye transmission.

 

So I cleaned up the transmission for the most part I have it narrow down to what I believe to be three leak locations one at the transmission dipstick grommet coming into the transmission the second being at the TV cable control arm rod that goes into the transmission from the side and the third being the transmission extension gasket so I've ordered these in preparation to repair them my next question for you is in the picture I sent in previous post that was of a ventilation gasket or ventilation part I've never noticed it before to me it seems like it's sticking out a lot is there any way to test it short of putting a hose over it and blowing forced air through it?