Transmission plug stripped at just over 15 ft lbs

I recently did drain and fills on the transmission.

I was under the truck for something else, and I decided to inspect the transmission drain plug.

What I found was that the entire pan was wet with oil, but it was not coming from above. I haven't driven all that many miles since the last drain and fill, but I was concerned that maybe I didn't have enough transmission fluid in there now depending on how much was leaking.

So I cleaned it up with brake cleaner, and drove about 30 miles.

This is what I saw. Drain and check plug both weeping:




So I figured that the crush washers that I bought on Amazon were not holding.

I bought some nice looking crush washers from the auto parts store, and came home and drained the transmission. When I put the drain plug back in with the new washer, I figured that I better torque it to spec instead of what I had been doing, which was to feel it out...feel the crush washer crush and snug up and a little more.

I set the nice electronic torque wrench to 29 ft-lbs and started slowly tightening. Just over 15, maybe about 17 or 19, the pressure dropped and the reading on the wrench dropped and my stomach dropped.

So now I have a stripped bolt.

Question - Does the bolt usually strip way before the threads on the pan? I'm hoping it is designed that way.

Thanks!

 

29 ft lbs looks a little heavy for those bolts. They are also lubed now because of the oil even though torque values are usually dry. But that’s just speculation.

Either way, that’s a bummer. I use the gaskets specified by Toyota and often get more than one use out of them; they are the correct thickness, and yield at the right force. I torque them by feel since I don’t trust that the torque value is correct due to oiled threads (as mentioned).

Usually the pan strips before the bolt, though I have seen both strip on an oil pan when the gasket is not used or the incorrect (thinner) gasket is used. In fact, my neighbor just did this exact same thing while changing the oil on somebody else’s car. The bolt wasn’t threaded all they way to the head and bottomed out the threads because they forgot to put on a washer. Upon inspection, both the pan and bolt threads were damaged.

Sounds like a good excuse for a deep pan from PML

 

Well, I like using problems as an opportunity to improve things. So this deep pan looks like you get 3.5 quarts over stock. And the fins help with cooling. So basically you are improving the cooling, is that the idea?

I'm kind of afraid to try to remove the bolts on this pan since I've read that many have had issues with them not wanting to come out and I think breaking, which would just present another problem to deal with.

I think there are replacement drain bolts with new threads that somehow tap themselves in aren't there?

 

According to this website:
https://yourcovers.com/search-by-vehicle.html

PML does not make a deep pan for my 4.6L

3 Matches To PML Parts Found For 2013 toyota tundra
Match 1 Tundra, Engine: 4.0L V6 (1GR-FE)
Transmission Pan Information: 5-Speed A750E/F 20 Bolt
Click on link for 11112: /pml-toyota-a750e-a750f-deep-transmission-pan.html

Rear Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

Front Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

Match 2 Tundra, Engine: 4.6L V8 (1UR-FE)
Transmission Pan Information:
PML does not make a transmission pan for this application. Contact PML if interested in one.

Rear Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

Front Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

Match 3 Tundra, Engine: 5.7L V8 (3UR-FE)
Transmission Pan Information: 6-Speed AB60E/F 12 Bolt
Click on link for 11151: /pml-toyota-ab60e-ab60f-deep-transmission-pan.html

Rear Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

Front Differential Cover Information:
PML does not make a differential cover for this application. Contact PML if interested in one.

 

I was searching Amazon for "self tapping drain plug kit" specifically for my vehicle, and it wanted more information about my vehicle's body code and transmission.

This is in my door jamb:



Amazon looks like this for body code:


Do you think it's OK to select UPK56 when mine is UPK56L. I would think so.

But then the transmission selection doesn't have mine exactly either:

Mine is A760H

Choices on Amazon are A760E or A760F. No choice for A760H:



Thanks!

 

I just chose UPK56 body and transmission A760E, because I figure it may be close enough.

Here is one option I found:
https://a.co/d/fttsCO6

It says it is M12.1. The stock one is M12 correct? So it is just a little bigger and self taps.

I'm not sure I'd be happy with this kind of thing or feel secure about it. Reviews talk about the copper crush washers that come with it being unique - maybe hard to find.

I've tapped things before myself but have limited experience so I wouldn't know what tap to buy or what size drill bit or what size new bolt, or where to buy this new drain bolt, but I'd be willing to try that if someone could walk me thru it.

Thanks!

 

The torque specs are 15 ft lbs for the transmission drain and check plug and 29 ft lbs for the transmission fill plug up top.

 

Thanks, well that's where I went wrong. I had 29 for the drain plug and 15 for the check plug. Thank you for letting me know!

 

I wouldn't even trust 15 ft lbs anymore, I'd go with feel.

 

Agreed, another poster here on the forum ran into the same issue and repaired it with JB Weld.

Cleanup

• Make sure all bolts are tight. Toyota specs call for the drain and check to be tightened to 15ft-lbs and the fill to go to 29ft-lbs. I do NOT recommend this. I stripped my drain port like this. Just tighten to "nice and tight" without over-doing it. Details in next post.
• Remove pin from trans cooler (if you have one).
• I marked the bolt positions with a paint marker to make sure they are not coming loose.

https://www.tundras.com/threads/2nd-gen-transmission-drain-and-fill-diy-how-to.137487/

 

How would it be repaired with JB weld?

 

Helicoil it

 

Looks like a good option, I'll have to look more into that.

I let the fluid drain more and got a good look at the threads in the pan. They look pretty good.

I've ordered a thread chaser that will be here early tomorrow and I'm going to get a new drain bolt today at Toyota along with OEM gaskets/washers.

One thing I can't find is a solid answer on the size and thread of that drain plug. The dealer couldn't tell me and the online parts don't list it either.

Chatgpt says it is M10 x 1.5.

Thanks!

 

Take it to any home imp. store or auto parts store and you can find a matching metric nut.

 

You need to get the shavings out of the pan too if you rethread it. Maybe salvage yard for a used pan will get you going better than anything else.

 

29lb is the engine oil drain plug. I think 15 felt too much for the trans even

 

Pull the pan and see what you are up against. If need be, buy a new pan. Replace the screen/filter while you are in there.

But, I would look at drilling and tapping the drain plug a little bigger or like others have suggested use a heli-coil.

 

For a few days you might get by with some teflon thread tape

 

The details were in the link I posted above. The poster mentioned 3 options to include new trans pan, tap new larger hole or JB weld the heck out of it and hope it never leaks.

Evidently they decided to go with JB Weld. Highly recommend reading the thread. Here's the link again.

https://www.tundras.com/threads/2nd-gen-transmission-drain-and-fill-diy-how-to.137487/

 

Might as well jb weld it and then you can deal with putting a new pan on in 30k miles

 

If mostly JB welded on the exterior it could be repeated easily multiple times. A stiff wire wheel will brush it off quite easily. Even silicone will hold it in and seal it up if done right.

 

^ This

 

Thread chaser (not tap) was run in just a turn or two, and that's all it needed. See video.

I had thick grease on the chaser to catch shavings. It hardly felt like it was doing anything.

The bolt went in nicely with a new crush washer and felt totally normal crushing the washer and coming to a stop tight.

Now I'm going to run some ATF into the fill hole with the drain open just to flush it a little.

Then fill it up, finish the process, use OEM washers for drain and check plugs, and see how it holds.

See video

https://youtube.com/shorts/1IpNX-5G6Do?si=fc4k_rNZxTLoSHYI

 

I’m going to guess you went with the good and tight torque values?

 

I did not use a torque wrench. I just used a ratchet and felt the washer crush and then did good and tight but not forcing it.

Then I backed it out, and was going to flush some ATF thru with it open, but more than a half a quart came rushing out and did that for me. I thought, that's strange, but then remembered that, I had been very careful this last time leveling the truck more than the previous time I had the drain open. So this time it was exactly level.

So then I filled it up and warmed the transmission to temperature and opened the check valve and only some fluid dribbled out, not even a stream. So I shut the truck off and in a little while I'm going to go back and fill it with another 2 quarts and then warm it again and do the check valve again. And use all new crush washers again. Fortunately I had gotten 4 of them from the dealer.

 

I also have 4.6L. Maybe i'll try drain and fill myself this time. My previous fluid was done by dealer.

 

I'm starting to like the smell of ATF. That's the 6th drain and fill this month. Fluid is looking much better in viscosity and color.

I put together a document that I print and take with me to do it, checking off each step as I go. It also contains links to videos I watched to learn it.

See attached pdf.

 

And that pdf contains a link to the washers that leaked on me, marked DO NOT BUY.

 

https://youtube.com/shorts/3ZR3pglvvKA?si=1qPHeWyvp4HbonCg