Auto Transmission Oil Pan/Drain Plug

connorwhite.online

connorwhite.online

Active Member
So I went to swap my ATF and found what seemed to be the obvious drain plug, but when I started turning the bolt just spun with resistance in place. Not sure if I have this wrong but from pictures this looks to be the right bolt. My immediate thought was that it was some sort of manual spin for an oil pump, similar to a sink garbage disposal, but that's probably not the case.

Additionally, my plan was to pop off the oil pan and get a fresh gasket on there, but I'm not sure how the oil cooler line comes out when you undo the pan bolts. Would love guidance on that.

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That is the drain bolt... if it just spins but doesn't leak I'm guessing there's some kind of weird bodge/fix for stripped pan threads (e.g. nut and rubber washer inside?)

That isn't a cooling line, it's the dipstick tube and it has a slip fitting/o-ring a few inches up... remove the dipstick/upper tube before dropping the pan.
 
Haha, ahhh the dipstick. I think I'm the dipstick. Is there a pressing need to replace that o-ring or does it seldom leak?

Should I just drop the pan and deal with the flood of oil? There may not be another way around it I guess.

Thanks sk66
 
I have changed the ATF and filter on a few vehicles. Most do not have drain plugs. You loosen up all the bolts but keep them in place, then loosen up more towards a corner and let it leak into your basin of choice. Without a drain plug it is a messy job. Luckily ATF comes out of the driveway pretty easy. I usually put a layer of cardboard down.
 
Okay, I like this combo. I'm going to do just that. Drain what I can out of a cooling line and catch the rest of the flood. I'll update later for the curious few as to what the other side of this bolt looks like.
 
The drain pan bolt had nothing on the other side of it.... there was a rubber washer on the exterior but not a thing inside the pan. The bolt just turned so I left it alone and painted over it. I'm quite perplexed but flushing the transmission from the oil return line was brilliant and I'll do it the same way next time.
 

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connorblanco said:
The drain pan bolt had nothing on the other side of it.... there was a rubber washer on the exterior but not a thing inside the pan. The bolt just turned so I left it alone and painted over it. I'm quite perplexed but flushing the transmission from the oil return line was brilliant and I'll do it the same way next time.
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I'm glad it worked for you; but I would be very concerned about a drain plug that doesn't tighten.
 
My drain plug also spins. What's worse is that it leaks. I want to stop the leak. I grabbed it with vice grips and pulled down while turning, but it just spun. Anybody got any experience with this or any suggestions?

I'm thinking about replacing the transmission pan with one that will allow a plug to tighten and not leak. I understand these transmissions were used in a lot of different vehicles. Do you think I could get a pan from a different make/model that will work with my transmission?
 
Fwiw, my TV recently developed this syndrome on the drain plug when I last did a flush. Months later and it still doesn't leak at all. Paranoia ensues.

In any case, it has to be stripped/ worn/flattened threads. Hopefully on the bolt, not the pan. My guess is the pans are thin and have too few threads at a bit too coarse of a pitch to fully engage after 30yrs of service. It's probably a good sign that the atf was changed on the regular.

I'd vote to extract the bolt, chase the threads and put a new bolt in. If that doesn't solve, maybe tap it out a size up with a finer thread pitch. Maybe they make a slightly fatter self tapper for trans pans, not sure but prob a decent one time fix (maybe combined w a perm sealant/fixative?) if they exist. I know there are kits to add a plug to a pan that never had one. Barring any of that, I like permanently sealing it shut via preferred method and simply draining your fluid by dropping the pan....but how are the threads on the pan holding up? Anyways, sounds like you kinda did the seal up w. epoxy. Hope it holds
 
Thomb said:
My drain plug also spins. What's worse is that it leaks. I want to stop the leak. I grabbed it with vice grips and pulled down while turning, but it just spun. Anybody got any experience with this or any suggestions?

I'm thinking about replacing the transmission pan with one that will allow a plug to tighten and not leak. I understand these transmissions were used in a lot of different vehicles. Do you think I could get a pan from a different make/model that will work with my transmission?
Click to expand...
Honestly, if I were to do it over again (and I will), I'd just JB Weld over the bolt internally and bypass the plug entirely. I have no need for it, I didn't spill much oil anyways just dropping the pan, and I always prefer to flush the cooler line first.
 
It may not be a stripped thread, that would most likely leak. Sounds like a crimped/riveted thread boss on to the sheet metal pan.
The more they slip the looser will get. Sometimes can get the plug out with very short bursts with a cordless rattle driver.
If you really want to fix it need to make up a mandrel & repress the crimp or TIG weld the boss to the pan.
I could be wrong, a close inspection would confirm.


I Live to Learn
 
Deli2au said:
It may not be a stripped thread, that would most likely leak. Sounds like a crimped/riveted thread boss on to the sheet metal pan.
The more they slip the looser will get. Sometimes can get the plug out with very short bursts with a cordless rattle driver.
If you really want to fix it need to make up a mandrel & repress the crimp or TIG weld the boss to the pan.
I could be wrong, a close inspection would confirm.


I Live to Learn
Click to expand...
Good thought there maybe! I wouldn't have guessed the boss was crimped or riveted on a part like that.
 
The threaded boss should be swage riveted to the sheet metal for optimum mechanical strength, but I suspect it's just a pressed rivet boss & if 'gorilla arm' over-tightens the plug bolt...
 
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