Hi all, was thinking of installing a drain plug in the tranny pan (4r70w). I was told not a real good idea because of pan being to thin. My intentions were not to get a bath while i change my filter and also to drain and add 5 fresh qts. every 10k or so. Truck has 40k, had tranny flushed at 28k and new filter at 35k Need a second opinion about the plug , thanx.

 

I say pull the pan, change your oil, and then determine weather or not you have enough room for a drain plug.

 

I don't think that it will be possible to put a drain on the pan unless you weld a bushing onto the pan to thread into. Put an aftermaket aluminum pan with plug on and you'd be better off.
When I don't want to change the filter too, I just use a drill powered pump and run the intake tube down the trans filler tube and suction the oil from the sump. Actually works very well, I found!

 

i put a drain in the 4r70w in my 95....worked fine....take it off...clean it out...drill the hole...tighten the plug bung down and then install the plug into the bung.

 

eBay Motors: B & M Automatic Transmission Drain Plug Kit NEW (item 370044089265 end time Apr-25-08 19:18:27 PDT)

 

If you have some extra cash, you could always get a new pan with a drain plug already installed.

Mag-Hytec makes one (Ford : Mag-Hytec) or PML has one too (PML Transmission Pan)

The Mag-Hytec has an o-ring to seal the pan. PML says the deep pan can use the re-usable OE gasket, but the shallow one still needs an old style gasket (not sure why they wouldn't have converted both of them).

 

there are plugs available that are a 1-time use plug..... mostly used for stripped out engine oil pan drain bolts..... but i dont see why one wouldnt work for your case.

but, since you would need to remove the pan regardless of which way you choose, then the best route would be to have a bung welded in place and use a normal plug. wouldnt cost very much to do, and the piece of mind would be well worth it knowing you wont get a leak and fry your tranny.