What does it mean to "tap" a drain plug thread?

[Bean Counter]

In my continuing saga to fix my perfectly running truck until its broken, I'm coming across the expression of tapping threads. I stripped my transmission drain plug (well, I hope its not the pan) and apparently per the Google machine this is a pretty common booboo. Plug spins freely but wont come out. Obviously since my fingers were spastic enough to strip it in the first place I am thinking of just taking the pan off but there's all that oil in there and I'd probably need to ruin a little kiddie pool to collect it all (it needs a drain and fill anyway). Does tapping it involve just using pliers, a screw driver, or a broken bottle and some proprietary Naval cursewords to get the damn thing out by any means necessary? Or is it something that is ran through the threads/hole after the fact to repair/straighten them? 

[fish vacuum]

Tapping is cutting new threads after the old plug is removed.

[Bean Counter]

thanks. is that easily done without special tools? Does it require a trained hand? A new pan is only $150.

[fish vacuum]

I've never done it. But what I've seen recommended is an oversized, self tapping drain plug.

[fish vacuum]

It used to be that the plug threads were more likely to strip than the pan threads. A new plug would solve that. With the materials used on newer rigs, the pan threads are more likely to strip.

[syoungs]

I'd probably just spend the 150$ on a new pan, but tapping the old one wouldn't be tough, especially if you can finagle that bolt out without taking it off the car somehow, and were able to capture the cutting chips ( run the tap covered In grease would work)

If you drop the pan anyways, a new pan and gasket would make the repair that much easier, and faster, and depending how much meat you've got around the pan to tap, it would probably be a stronger repair you wouldn't have to worry about in the future.

[Woodchuck]

If you aren't 100% sure how to do it, just replace the pan. 

[Fl0und3rz]

Pick and pull or craigslist should get you off pretty cheap and with far less frustration.

[JimmyHoffa]

The tool looks kind of like a drill bit with straight flutes.  It would be slightly larger than the hole, and you twist it in--cutting new threads.  Then you use a bolt that fits the new threads. 
Like mentioned above, you have to clear as many chips as possible.
Depending on orientation of the other bolts on the pan, it might or might not be easier to just swap out a new pan.  Then you have an extra once you tap the hole.

[rtspring]

Tapping a hole is easy, provided you have enough metal left over to tap new threads, and enough room to use tap and tool.  Use alot of lubricating oil,  start it straight!  1 turn forward and then back half of turn to clean out debri.

I would for sure remove pan to drill and or tap existing hole or make larger hole to tap new threads. Some metals are harder, ie stainless, titanium and such.

Go slow!

[rtspring]

Also a wel shop can simply weld up old hole and cut new one and insert a fitting with threads already tapped then weld it in.   Fairly simple task. 

[netcoyote]

If you've already stripped the threads on the existing hole, you will have to go up one size larger on the tap size and that may require re-drilling to the proper tap hole size. There are charts that show tap hole sizes but this sounds like it's getting beyond your skill level. It's not that hard but you should probably consult with someone with some machining experience.

[jackelope]

If you aren't 100% sure how to do it, just replace the pan. 

I agree with this. If for nothing else, the cheap insurance that your makeshift repair won't fail on you in the middle of nowhere. No offense, but if you have to ask the questions you've asked re: what it means to tap threads, what tools, etc... this is not a repair that I would take on. You'll have to remove the pan. You don't want any unwanted metal debris ending up in the pan. You'll need large drill bit, a tap, a new drain plug, and probably a few other things I'm not thinking of at the moment. Then you need to "hope" you drill the hole straight, etc.
Buy the pan.

[Fl0und3rz]

I know what I am doing, and I would rather just replace the pan, simply out of relative ease and surety of the repair.

[Encore 280]

Since it's a pretty common problem the pan threads are usually a harder metal than the plug so hopefully it's just the plug that's stripped and you can go to an auto parts place and get a new plug. Worse comes to worse maybe you can do the HeliCoil (sp) trick. Just my 

[baker5150]

If it's a common problem, maybe look at an aftermarket pan?  I personally wouldn't want to replace it with a new pan that could have the same issue with stripping out.
Depending on Make and Model truck, aftermarket pans may be available.

[mazama]

Oil plug on my diesel pickup was loosedid'nt feel like fixing it so I cleaned with brake cleaner and put Red high temp sealer on it,years ago I gashed an oil pan,cleaned it put red high temp on it,never leaked.

[netcoyote]

Unless it's an older truck, dropping the pan may be out of the question. I've seen some pretty tight clearances in newer rigs for pan removal. Better check with someone who knows your vehicle and can give advice. I'd agree that replacing the pan would be the best solution but the devil is always in the details; i.e. pan removal.

[eastsidemallard74]

Just buy an oversized drain plug,it should just re thread the old pan.

[Dan-o]

Just buy an oversized drain plug,it should just re thread the old pan.

I've done this twice with good results.

[Woodchuck]

Bean, take it to a shop, get it done right. Sometimes the peace of mind is worth it.
For me this is like what it would be for you if someone was on here asking for tax advice from the Hunt-Wa collective. Take your own advice, the risk ain't worth it. 

[Dan-o]

Do what you want, but it really is easy to install one of the oversized selftapping ones.

Think of it this way:
  *  America was built by men who could install a selftapping plug.     
  *  Trump would just pay someone else to do it.

[coachcw]

Id try and get a screw driver or a scrapper under the edge of it and spin it out . once you get it out you can see if its the plug or the pan . if the pan is stripped then honestly id just get a new one . no reason to loose your fluid on some mountain road . often I see the drain plugs are sacrificial and loose there threads first.

[Bean Counter]

Id try and get a screw driver or a scrapper under the edge of it and spin it out . once you get it out you can see if its the plug or the pan . if the pan is stripped then honestly id just get a new one . no reason to loose your fluid on some mountain road . often I see the drain plugs are sacrificial and loose there threads first.

Yep. I called my local repair shop and he told me to call O'Reilly/Checker/Shucks as they sell a temporary rubber plug made for people like me, whose education exceeds their intelligence, in case the pan is toast and it will allow me to skate by for a few days whilst I await for a new pan order from Toyota. 

[Bean Counter]

Update: With a gentle pull of the pliers straight down, I was able to get it off with the socket.

How bad is it, doc? 

[et1702]

Id try and get a screw driver or a scrapper under the edge of it and spin it out . once you get it out you can see if its the plug or the pan . if the pan is stripped then honestly id just get a new one . no reason to loose your fluid on some mountain road . often I see the drain plugs are sacrificial and loose there threads first.

Yep. I called my local repair shop and he told me to call O'Reilly/Checker/Shucks as they sell a temporary rubber plug made for people like me, whose education exceeds their intelligence, in case the pan is toast and it will allow me to skate by for a few days whilst I await for a new pan order from Toyota. 

Hey Bean,  on-line car parts source will likely be much cheaper than dealer (e.g., Rockauto.com or similar)  Many have dealer parts too, instead of Chinese knock-offs.

ET

[JimmyHoffa]

Update: With a gentle pull of the pliers straight down, I was able to get it off with the socket.

How bad is it, doc? 

yeah, that plug has seen better days.  Is the hole destroyed too?  Or did it survive at the expense of the plug?

[Encore 280]

Find a small cylindrical magnet that will fit in the hole and move it around inside to see if you can pick up any metal shavings. You don't want shavings in your oil. Even if you drained the oil there may still be shavings in there. Check to see if the bad plug is magnetic or not. Some plugs are so they pick up any metal that's in that area of the pan. I would get a new plug and see how it screws into the pan, you'll be able to tell if the threads are good or bad, cheaper than buying a new pan. Don't over tighten.

[syoungs]

Looks to me that the plug pulled the threads out off the pan,  if it were me I'd spend the 150$ and be done with it forever, knowing it's right.

[jackelope]

Update: With a gentle pull of the pliers straight down, I was able to get it off with the socket.

How bad is it, doc? 

Definitely don't try to tap anything. You really need to be looking at the condition of the pan itself and not the plug. Those plugs are designed to do that. You'll ruin the plug before you ruin the pan. What's the threads in the pan look like?
Maybe the threads pulled out of the pan or maybe the threads on the plug flattened out because it was overtightened.

[jackelope]

Do what you want, but it really is easy to install one of the oversized selftapping ones.

Think of it this way:
  *  America was built by men who could install a selftapping plug.     
  *  Trump would just pay someone else to do it.

We refuse to install these at my shop. Too much liability. If it fails, you're ultra screwed. If the shop installs it, they're on the hook for it.
Ain't happening....

[Bean Counter]

Update: With a gentle pull of the pliers straight down, I was able to get it off with the socket.

How bad is it, doc? 

Definitely don't try to tap anything. You really need to be looking at the condition of the pan itself and not the plug. Those plugs are designed to do that. You'll ruin the plug before you ruin the pan. What's the threads in the pan look like?

To be honest they kind of looked like the drain plug. but, I got the new one in there! 

SUCCESS.

Thank you, Hive Mind. You have helped me stay true to my inner city, Section 8 Housing roots.

[mazama]

My old memory has kicked in,I was told years ago that oil plugs were softer than the pan so that they would strip before the pan would.

[timberghost72]

Unless the pan is aluminum.