Welding ATF drain plug bung onto pan

[92saturnsl2]

I borrowed a welder from a buddy for the weekend (for another project) and I figure it'd be a great time to drop the ATF pan on my Pacifica and weld a bung for installing a drain plug. The pan is not hard to drop, but it'd sure make future fluid exchanges a lot less messy.

For those that have done this, have you used a simple ordinary nut welded to the inside of the pan, and use a matching bolt with copper washer? I have some spare drain plugs that have a rubber o-ring built into head of the bolt, not sure if that would work better or worse than a simple copper washer like is common on oil pan drain plugs.

Or should I be buying something specific for this application (something along these lines: https://www.summitracing.com/parts/mor-68900)? I can't see how an ordinary nut wouldn't work the same, other than not having as much surface area to weld, but that shouldn't be an issue, I can get a solid weld on either.

Curious to hear how others have gone about this.

 

[bullwinkle]

I had a welder weld an EGR bung onto a steel rear diff cover for the GMC C3500 in my sig (I was careless & stripped out the factory one in the case)-I'm not sure I would trust my welding skills enough to get a leak-free weld!

 

[maxdustington]

The nut would be at the lowest point possible, whereas that insert would stick up into the pan. A nut is also way cheaper and you can use those spare drain plugs.

 

[92saturnsl2]

Nut should be welded to INSIDE the pan, correct? I think outside the pan would be exposed to road debris and such and provide a much smaller sealing surface. Am I correct in my thinking?

 

[Linctex]

Only TIG weld this - ONLY.

MIG if it is .020" wire and your skills are up.

Any other type of welder - forget it, unless you are a seasoned pro.

 

[Linctex]

Or, just go to the auto parts store and get one of these:

https://www.summitracing.com/parts/bmm-80250

 

[eljefino]

If you're not great at welding and you blow through the bottom of your pan, what's your plan B?

For a rookie welder doing the inside nut is the only way to go. The outer washer will seal. I'd get a nice fat headed drain bolt with nylon washer but am open to ideas.

Just getting most of the fluid out the drain hole is helpful, you'll still drop it to get the filter, just won't be as messy.

 

[MasterSolenoid]

I asked my Nephew to weld a hex nut to the outside of my Trans. Pan.
That worked great for me.

If the nut is welded inside, you won't get as much fluid out (if that matters).

1) Weld Nut on
2) Drill thru hole
3) Use a Magnetic Drain Plug

I also added 3 'extra' magnets while I had the Pan off.
I used some rare earth magnets.

 

[Bluestream]

Originally Posted by Linctex
Only TIG weld this - ONLY.

MIG if it is .020" wire and your skills are up.

Any other type of welder - forget it, unless you are a seasoned pro.


True, but you can braze these in very easy as there's no stress on them. Must be 10,000 threads on this

 

[maxdustington]

Originally Posted by Linctex
Or, just go to the auto parts store and get one of these:

https://www.summitracing.com/parts/bmm-80250
OP wants to weld, did you not see his first post?

 

[92saturnsl2]

No plan B, I do metal fabrication for a living, the pan in question is thick enough that I could stick weld it if I had to

It'll MIG just fine with the 0.030 hard wire I've got.

I'll have to take another look where the lowest part of the pan is, I do like the idea of putting nut on the outside to get more fluid out. I plan in doing a fluid r&r every 25-30k or so (I can only drain about 4.5qt); filter will probably be every other pan drain, so the more fluid I can get out through the drain plug, the better.

No one has had any sealing issues with the nut facing outside, and the plug sealing to just the nut? That is my main concern putting the nut on the outside. Is a copper washer all I need for sealing?

 

[KrisZ]

I would Try to get to the ATF cooler lines. It looks like it should not be too difficult. I would leave welding to more experienced people.

 

[Chris142]

I did this to my wife's Tahoe. Its a strange metal. No solder would stick to it. Had to braze it.

 

[MasterSolenoid]

Hex Nuts come in different duties.
Try and get a 'heavy' duty nut (extra wide).
NOT some light duty nut from the Hardware Store.
https://www.mcmaster.com/hex-nuts

Heavy Duty and you stand a better chance of NO distortion on sealing surface / if welding on the outside of Pan.
I just used an aluminum washer with NO problems.

 

[Mainia]

I Tig weld a Grade 8 nut on the side or back outside You won't ever ounce out but 99.5% works for me.

 

[slacktide_bitog]

I would just buy an aftermarket pan with a drain plug

The pans are so cheap it's not really worth messing with the original pan. About $30 from Rock Auto

Is the Pacifica's transmission any better than the minivan's transmissions? With the drain pplug, you can change the ATF with Redline C+ every year

 

[Linctex]

Originally Posted by maxdustington
Originally Posted by Linctex
Or, just go to the auto parts store and get one of these:

https://www.summitracing.com/parts/bmm-80250
OP wants to weld, did you not see his first post?


YES - I did read it .....but I was suggesting something he "perhaps" (I'm not a mind reader) didn't know existed....

and you don't have to be a complete Donkey rear about it, OK?

 

[berniedd]

Maybe welding the nut outside of the pan is a good idea. If it leaks at the weld later, you have access to the nut and do a reweld. If the nut were inside the pan, you'd have to drop the pan again.

 

[Trav]

Just find the correct location where the drain bolt wont touch anything, mark it, drill it and get a wide square nut and tack it well on 2 sides and your done. Us a large face drain bolt and aluminum washer.

 

[92saturnsl2]

Tackled the job this afternoon and it was smooth sailing. The oil pan was a lot thicker than I would have guessed, it's 11 gauge stamped steel plate, so the possibilities/methods for welding it are endless.

I dug through my bin of extra bolts (most came from parts I acquired from pick&pull junkyards) and found something fine-thread that wasn't too long. The nut that matched was perfect for this application because it had a big wide shoulder. I drilled the hole large enough to put the entire hex of the nut through the pan, and used the shoulder of the nut as a flange of sorts, which gave me a good amount of surface area to weld without getting the nut/threads way too hot. It's not completely flush in the inside of the pan, but closer than if I had welded the whole nut on the inside. So perhaps not every drop will escape, but pretty close! Cleaned everything up real well and threw a coat of paint on it.

This will save a lot of time & a lot less mess, even when I have to drop the pan to change the filter. Why these don't come with plugs from the factory is beyond me...