Tranny drain bolt spinning?

The transmission pan drain bolt kept turning when trying to apply 21 ft lbs of force to tighten. It seems like the welded nut inside the pan is turning. Not a drop of fluid is leaking after driving a few days.
Anyone else experienced this?
Guess I'll have to order another pan but was wondering if I could get the nut welded back on if that is the case?

 

https://www.tacomaworld.com/threads/stripped-transmission-plug.197143
https://www.tacomaworld.com/threads/stripped-drain-plug.120337

 

I brought this up in the thread on how to drain/fill the transmission.

The spec needs to be revised to 16 lb-ft when used with a fresh crush washer. If it's spinning at 21, you either stripped the bolt or the pan.

 

Thanks, wish I had read all that...

Not leaking so I'm thinking the welded nut broke free.

Would like to hear from someone who actually welded the nut back on. I would try but this is my daily driver.

Local dealer I bought my truck from wants $170 for just the pan but I found another dealer asking $90.

 

Welding the nut onto the drain pan isn't that uncommon. Many older vehicles didn't come with a drain plug and I've added them by welding an aftermarket plug kit into the pan. Drop the pan, clean it up and weld 'er up (TiG would probably be best but I've used a MiG welder without incident).

 

Check out the video below - 12min 40sec into it you see the inside of an A750 pan - drain plug area on the right. You might want to back up a little before 12m40s to get your bearings straight.

Doesn't look like a welded nut to me. Maybe some pans had a welded nut.

https://www.youtube.com/watch?v=P1XdzmjdsPo

 

Looks like the female threads are molded into the body of the pan. Bad design for something that most people are going to end up over-torquing. Doesn't help that the widely available torque spec is flat out wrong.

I would be ready to buy a new pan, but I'm curious if there is enough room to heli-coil it since that usually ends up in a stronger solution anyway.

 

Looks like a glued (?) round nut on the new pan. No wonder it spins but doesn't leak.
Looks repairable, guess I'll have a spare pan.

 

Is that not molded in? At least it looks like there is enough material to drill and tap to the next size.

 

Here is a closeup

 

Thanks for posting up the good pics. I see what you mean now -- the extra torque just breaks it loose from the pan...

Is the pan made of steel? It looks like you could weld a proper nut on there.

 

Sure looks like steel. Maybe able to weld the round one back on if threads not damaged.
Have to wonder why it has such a weak bond.

 

Weak bond or Ham Fist.... At least it doesn't strip out the threads. That would be repairable IMO.

 

Just get a size bigger self tapping drain plug

 

The pan insert is spinning.

 

Ham Fist torque wrench!

 

In all of my many years I have never used a torque wrench on a oil pan / transmission pan drain plug... I trust my sense of feel. Head bolts and things yes, drain plug with a gasket I have no need.

 

Just found out one of my sons was using my 3/8" torque wrench as a breaker bar to loosen lug nuts. Could explain the 21 ft lb setting stripped the bolt. Said torque wrench trashed.
I installed the new pan today and torqued the drain plug and overflow plug to 150 inch lbs or 12 ft lbs (max setting) using a Klein 3/8" torque wrench.
My third 1/2" torque wrench starts at 25 ft lbs.
I used a new correct crush washer on the drain and a new engine oil drain washer on the overflow. Both held all day as well as the 39 inch lbs on the pan bolts with a Toyota gasket.

 

I know a son that needs an ass whippin!

 

How about an aftermarket drain plug? I use to add them to my F150s at the first fluid change. When I felt mine getting snug well before 21 ft lbs I quit tightening.