Stripped torque converter drain plug

[Kyiv]

Tried to drain ATF today, on Friday (my Friday evenings are fun!). Found the torque converter drain plug stripped . Removing exhaust pipe that connects to driver side header looks daunting, especially considering I'm just using ramps. I'm sure even with ramps I could reach the bolts, but there are nuts on the other side, which seem inaccessible from either top or bottom...(?)

Anyways, is there someone with an actual experience who can recommended the most efficient way to extract that torque converter plug? I see that Amazon has all kinds of "stripped bolt" removers, but which one is the most appropriate for the torque converter of my 400E that is on ramps, with exhaust in place?

The plug was a 5mm hex. I tried to get a bite on it with pliers, but there isn't enough space to produce a lever effect.

 

[heikkif]

Would you dare hammering a triple square into it? With stripped 6mm allen screws that works.

Or do several partial oil changes.

 

[emerydc8]

I don't have experience specifically with a stripped torque converter drain plug, but one thing I recently concluded is that pretty much every type/brand of extractor tool is slightly different and they're not too expensive on Amazon. I can usually find one in my collection that will work where others won't. As Heikkif suggested, maybe a triple-square bit will work.

Do you have a drive impact screwdriver?. https://www.amazon.com/TEKTON-2910-2-Inch-Manual-7-Piece/dp/B000NPUJYE/ref=sr_1_4?dchild=1&keywords=impact+driver+1/2"+hammer&qid=1624086948&sr=8-4

 

[speedy300dturbo]

You need something that'll bite into the stripped remains of that bolt. This should work: Amazon.com: Neiko 04204A Hex Head Multi-Spline Screw and Bolt Extractor Set | 25 Piece | 1/8” to 7/8” in 1/32” Increment | Cr-Mo: Automotive

 

[Kyiv]

Would you dare hammering a triple square into it? With stripped 6mm allen screws that works.

Or do several partial oil changes.

You actually mean hummer it in, correct? Then once it sank in nicely, put a ratchet on it and turn the plug out? I'm very new to this, so want to be precise in my understanding. Thanks

***Like these, correct?

 

[Kyiv]

You need something that'll bite into the stripped remains of that bolt. This should work: Amazon.com: Neiko 04204A Hex Head Multi-Spline Screw and Bolt Extractor Set | 25 Piece | 1/8” to 7/8” in 1/32” Increment | Cr-Mo: Automotive

View attachment 133315

Sorry for the ignorant question, but what do you drive these bits with? They have, what seems, hex-shaped bottoms... Thanks

 

[emerydc8]

Sorry for the ignorant question, but what do you drive these bits with? They have, what seems, hex-shaped bottoms... Thanks

One of the sockets in your 1/4" drive socket set will fit the bits. Also, Lowes and Home Depot usually carry triple-square kits. There's likely only one size in the kit that might get a bite on the plug, but it's worth a try.

 

[Kyiv]

One of the sockets in your 1/4" drive socket set will fit the bits. Also, Lowes and Home Depot usually carry triple-square kits. There's likely only one size in the kit that might get a bite on the plug, but it's worth a try.

@emerydc8, thanks. I've already ordered kit from the Link you've provided. But I'm still confused what drives hex-shaped nests of the bits from speedy300's link. Can't put a ratchet on them and neither my impact gun, which have square inserts... What is English name for the right adapter?

 

[heikkif]

***Like these, correct?

Yes when one hammers that into a stripped allen head it becomes formed into a triple square. Only risk I see here if the converter shell takes the hammering without a permanent deformation.

 

[speedy300dturbo]

@emerydc8, thanks. I've already ordered kit from the Link you've provided. But I'm still confused what drives hex-shaped nests of the bits from speedy300's link. Can't put a ratchet on them and neither my impact gun, which have square inserts... What is English name for the right adapter?

Kiev, you can just use the appropriate size socket to fit over the hex end of the extractor after you hammer it into the stripped bolt. I suggest using an actual extractor for this job. Although hammering a triple-square or torx bit into a the stripped bolt might work, I prefer using tools that are designed for extraction.

 

[liviu165]

I sincerely recommend not to hammer anything and just leave it as is. Hammering something in there may or may not damage the converter, but if it does or it ends creating some misalignment, then you have a major issue to solve. IMHO, the benefit of getting that plug out does not offset the potential damage. I've seen cases when what was supposed to be a minor issue, snowballed into a major one very fast.

As recommended already, perform the oil changes more often. I am not familiar with the oil requirements for your car, but if it would be one of my cars I would buy the transmission oil from the dealer (for the W126 transmission is PN Q1090074, less than $5/qt.), I would change it now and again in about few months. Your car may use the same transmission oil, which BTW, PN Q1090074 is nothing else but Mobil ATF D/M transmission oil.

To avoid the pain of getting under the car, you could use an oil extractor (~ $100) that would extract the oil thru the dip stick tube. I have one and used with great success several times on various cars.

Anyway, that's what I would do.

 

[emerydc8]

@emerydc8, thanks. I've already ordered kit from the Link you've provided. But I'm still confused what drives hex-shaped nests of the bits from speedy300's link. Can't put a ratchet on them and neither my impact gun, which have square inserts... What is English name for the right adapter?

Use a regular 1/4" drive ratchet and a deep socket. In the picture, the 1/4" socket barely reaches to the extractor bit, so you may have to use a deep socket depending on how your bits are designed. (If you ordered the kit in Speedy's link above it doesn't look like you'll need a deep socket.) The larger you go in extractor bits, the larger socket size you may need. If the socket is loose and you're concerned about the bit dropping into the black hole, use a small piece of shop towel in the socket to hold the bit. Incidentally, the cap-head bolt in my pic takes a 5 mm Allen.

 

[kwontumspeed]

Leave it. Increase change intervals. Next time it goes to the Indy have them do it. They’ll have the tools and the charge should be very minimal if any cost at all if you are an established customer. (Unless it’s terribly involved, but if it is you’ll be glad you weren’t the one tackling it anyway).

 

[gsxr]

If the plug is not excessively tight... another option is to use a small cold chisel on the edge of the plug, and GENTLY tap it in the correct direction. You only need enough to jar it loose, and you are golden. The advantage here is the impact is not towards the converter surface (axial?), it's along the direction of drain plug rotation (radial?).

An extractor that would grip the outer edge would be ideal but may be tough to get the exact size.

I agree that hammering is not ideal, but gently tapping an extractor on should not hurt the converter. It's beefy and unless you are totally hamfisted, it would be hard to damage or deform it, IMO. Anyone who has lifted an empty converter knows what I'm talking about.

 

[gerryvz]

If it were me, I'd gently tap an XZM (triple-square) or Torx bit, slightly oversize, into that hex-bolt hole. Should come out easy enough if you are gentle and use the right over-size bit. Done this many time for various types of stripped bolts. Has nearly always worked well.

95% chance this will work well if you get a Torx bit of correct size that will give it a good bite.

Cheers,
Gerry

 

[TerryA]

Kiev, you can just use the appropriate size socket to fit over the hex end of the extractor after you hammer it into the stripped bolt. I suggest using an actual extractor for this job. Although hammering a triple-square or torx bit into a the stripped bolt might work, I prefer using tools that are designed for extraction.

@kiev +1 on using Speedy’s extractor Kit. This type of extractor is the proper tool to use. If you look close up at the extractor bits you will see that they are designed with spiral reverse threads designed to dig in to the stripped out hole as you attempt to back out the plug.

Hammering in the hex heads may just enlarge the hole when you attempt to back it out.

 

[JC220]

If the plug is not excessively tight... another option is to use a small cold chisel on the edge of the plug, and GENTLY tap it in the correct direction. You only need enough to jar it loose, and you are golden. The advantage here is the impact is not towards the converter surface (axial?), it's along the direction of drain plug rotation (radial?).

An extractor that would grip the outer edge would be ideal but may be tough to get the exact size.

I agree that hammering is not ideal, but gently tapping an extractor on should not hurt the converter. It's beefy and unless you are totally hamfisted, it would be hard to damage or deform it, IMO. Anyone who has lifted an empty converter knows what I'm talking about.

If it were me, I'd gently tap an XZM (triple-square) or Torx bit, slightly oversize, into that hex-bolt hole. Should come out easy enough if you are gentle and use the right over-size bit. Done this many time for various types of stripped bolts. Has nearly always worked well.

95% chance this will work well if you get a Torx bit of correct size that will give it a good bite.

Cheers,
Gerry

+1 on both posts above!

I'd try a torx first. Don't worry about deforming the torque converter. It is made from like 8mm thick mild steel.

Never had much luck with any internal extractors. Normally they shear off inside and cause a bigger issue. Gixers cold chisel suggestion is also a good one.

Get a quality chisel (not chinatown) and Sharpen the edge with a grinder. Tap it to get a bite on an edge and hit it a few raps it should shock it loose. Alternatively an impact driver tool with bit would work well. That is; the old school manual tool that you rotate and hit with a hammer to shock seized fasteners free. They do come with torx bits or try a small dremmel wheel to cut a slot and get purchase on the plug if there is just enough access(?)

Then fit a new plug and washer and don't overtighten like the last guy.

 

[emerydc8]

With all the discussion about extractors, I decided to look around and see if I could add more to my toolbox. One of the hardest things for me has been to drill out the center of a broken M5 or M6 bolt thread. None of my punches seems to be capable of marking the center well enough to keep the drill bit from walking all over.

I ordered this Rennsteig [Knipex / Germany] extractor which uses the narrow pointed end as a center punch and the extractor further down:

https://www.amazon.com/gp/product/B00DEMVY74/

I also ordered some Lichamp 1/8" cobalt drill bits that are triple-fluted, hoping that they will be able to stay centered and cut into the factory bolts. Lichamp 1/8" HSS Cobalt Drill Bits 10PCS with Three Flute for Hard Metal, Hardened Stainless Steel and Cast Iron: Amazon.com: Industrial & Scientific

Now I just need a broken bolt to test it on. Thanks to @gsxr I found some more info on this tool from Knipex: https://www.knipex-tools.com/products/rennsteig/

 

[Kyiv]

Thank you all for your differing advices. That's the kind of diversity I'm onboard with!

Anyways, a few, relatively mild taps on a longish triple square bit, and it sank in nicely into converter's drain plug. Mild force on the ratchet and the plug broke lose.



My goal is to let torque converter and the tranny drain overnight and, tomorrow morning, fill in 2 gallons of D4 ATF.

 

[sheward]

+1 on both posts above!

I'd try a torx first. Don't worry about deforming the torque converter. It is made from like 8mm thick mild steel.

Never had much luck with any internal extractors. Normally they shear off inside and cause a bigger issue. Gixers cold chisel suggestion is also a good one.

Get a quality chisel (not chinatown) and Sharpen the edge with a grinder. Tap it to get a bite on an edge and hit it a few raps it should shock it loose. Alternatively an impact driver tool with bit would work well. That is; the old school manual tool that you rotate and hit with a hammer to shock seized fasteners free. They do come with torx bits or try a small dremmel wheel to cut a slot and get purchase on the plug if there is just enough access(?)

Then fit a new plug and washer and don't overtighten like the last guy.

I haven't heard anyone lately mention the impact driver. I've had one since my early motorcycle days. Great simple tool.

Glad you had success, Kiev.

drew

 

[gerryvz]

Thank you all for your differing advices. That's the kind of diversity I'm onboard with!

Anyways, a few, relatively mild taps on a longish triple square bit, and it sank in nicely into converter's drain plug. Mild force on the ratchet and the plug broke lose.

View attachment 133565View attachment 133566

My goal is to let torque converter and the tranny drain overnight and, tomorrow morning, fill in 2 gallons of D4 ATF.

Glad the GVZ method worked. As I mentioned, it has worked for me about 90% of the time when I have a stripped bolt like this. Particularly a soft one that isn't horribly torqued in like an oilpan bolt.

 

[Kyiv]

Glad the GVZ method worked.

We should also give credit to Mannerheim's countryman @heikkif , who was the first to propose such method.

 

[gerryvz]

We should also give credit to Mannerheim's countryman @heikkif , who was the first to propose such method.

Yes! Absolutely! Of course !