Transmission Drain and Refill Question/Mistake

Relatively new to maintenance beyond oil changes, and looking for some advice. I went to replace my transmission fluid for the first time and made the mistake of not checking that I could remove the fill plug before draining the pan. The bolt in the fill line is firmly stuck and I stopped trying when my 24 mm socket started to slip and round over the corners since I didn't want to make things worse than they already were. I estimate ~2.5 qts of fluid drained out. As a short term fix I managed to rig up a makeshift fill plug to fit in the check port and pumped in about 3 qts. When I removed the fill rig from the check port some excess drained out. While it was still draining I went ahead and reinstalled the check plug. I then went through the normal procedure to cycle through the gears, then enter temp check mode and checked the level.

Here is where it gets a little weird... Once at temp, absolutely no fluid drained from the check port. So as things currently are, I have refilled the transmission pan with approximately the same amount of fluid that I drained and I didn't experience any weird noises or vibrations while shifting through the gears. My plan is to order more fluid and a 15/16" socket since I read those tend to be a better fit on these plugs. Then I'll soak some WD-40 on the bolt and try to break it loose again. If that succeeds I will top off the transmission with another quart or so and re-attempt the level check procedure. If the bolt is still totally stuck, I don't know what to do next.

What do y'all think of this approach? What should I do if I still can't remove the bolt with the 15/16" socket? Do you think it is okay to drive on in the short term to get the additional fluid and socket?

Despite the frustrations and anxiety, at least I learned something out of this. And I am not yet deterred from continuing to learn some DIY maintenance.

 

By the "check port" I'm assuming you are talking about the one high up, and back, on the passenger side? If so, that represents a lot of extra capacity level. If you guessed you drained 2.5Q and added 3Q you would not get overflow out that high port. Skip the WD-40 and go with something like PB Blaster. Let is soak for a day. As for your socket, be sure to get a 6 point as opposed to a 12 point. Configure the ratchet without any extensions. If you can, put a little heat on the pan around the plug - goal is to expand the hole without adding too much heat to the plug.

 

The check plug I am referring to is shown in this post: https://www.tacomaworld.com/threads/stripped-hex-head-on-transmission-fluid-check-plug.546528/
How would you go about heating it? Would as little heat as a blow dryer work or are we talking heatgun/torch?

 

The transmission fill plug is usually not that bad, since it's relatively high up in the vehicle (compared to the rear diff plugs for example). Are you using a 6-point shallow socket? Don't use 12-pt and don't use a deep socket.

 

When you checked the trans fluid, was the engine running? Engine needs to be running.

 

Yes, it was running and at the correct temperature. After entering temp check mode I waited until the Drive indicator appeared on the dash. I removed the check plug, no fluid came out. Then I reinstalled the check plug and confirmed the drive indicator was not yet flashing to show that it was over the right temperature.

 

There is a long-running thread stickied at the top of this forum section, alleging the transmission was under-filled from the factory: https://www.tacomaworld.com/threads...be-low-on-fluid-directly-from-factory.405642/ Might be the reason you're seeing the discrepancy.

 

So if I'm understanding you, the plug you are having trouble with is the fill plug up high on the side of the trans. Yeah it's going to be a challenge to get heat to that one. As for not getting fluid out of the check plug you used to refill - I would not be worried, as it is not uncommon for these trans to be under filled. I'm sure you are close enough for the moment. You'll get a chance to get it right once you get the fill plug out. 6 point socket - steady slow pressure while pressing down. You'll get it.

 

Thanks for the feedback. Because the current level is close to what it was before I am hoping you are right and I can drive it for a day or two to get the parts and work tomorrow lol. Then once I have time tomorrow afternoon I will try to finish topping it off.

 

Follow-up time!

I finally got around to making things right with my transmission. Used a 15/16" socket on a longer ratchet and with slow, deliberate force got the fill plug to come loose. From there the rest of the procedure was pretty easy. Pumped in about two more quarts, did the level check procedure with the engine running at the right temp, and got a small amount of overflow which quickly reduced to a trickle. The bad news is based on the fact that I drained close to two quarts the first time and added back 4 quarts it looks like my vehicle was in fact low in transmission fluid from the factory. This lines up with the post linked by @3JOH22A. The truck has ~56,000 miles on it in that condition. Didn't notice any metal fragments when I drained and I've never had a high transmission temp warning. The old fluid also didn't look burned so I am hoping no harm came from this condition over the last few years.

All in all, this was a good learning experience. Thankyou everyone for the help and thanks everyone for not flaming the rookie (me) in this thread!