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I got this drain plug kit at Transtar for $11.30. Hayden Automotive part number 270. All you need is a 1/2" hole in your pan. This makes it infinitely easier and cleaner to change your trans oil.
I did a drain plug in my 4T65E using an O2 weld in bung along with a correct hex drive plug similar to this offering from J&P Cycle. The bung has the reduced diameter lip and a TIG weld finished it off well. I've done similar to many. The difference in mine and the image from J&P was I used a Toyota plug and gasket to finish mine off. The bungs are available both locally and real inexpensive on eBay. The plug and gasket was maybe $6 locally.
Put one on a th350 of mine over 15yrs ago and it always dripped. When I went to use the drain just last fall it spun on me, so I tried to use a backer wreck and the little plug stripped. I then took my die grinder and just cut the pan because I had a new one for that trans anyway.
Can't say if install was perfect it was so long ago, I maybe used the drain once. Hope you have better luck, but mine was just like yours Cliff.
I got this drain plug kit at Transtar for $11.30. Hayden Automotive part number 270. All you need is a 1/2" hole in your pan. This makes it infinitely easier and cleaner to change your trans oil.
I think i recall you were installing one for your rear differential as well? Did you ever settle on the correct location and bung size? If so where did you source the parts? And do you have a photograph of wear on the differential you drilled and tapped your hole?
Just an observation/warning from experience: these plugs can be torn out on a speed bump. The details are gross, speed bumps should be banned, but... it can happen
I've run one for years without a problem. Locktite the nut and tighten well. My engine oil pan, and exhaust were always much lower than the pan. Never scraped the pan or bolt. It made tranny oil changes much easier.
I think i recall you were installing one for your rear differential as well? Did you ever settle on the correct location and bung size? If so where did you source the parts? And do you have a photograph of wear on the differential you drilled and tapped your hole?
That is my next project. From what I could tell, the hole needs to be 1/2" forward of the gasket surface and 1/2" to the passenger side of the casting line for a D36.
I'm using a 1/8 x 27 NPT stainless steel plug with a hex socket. The drill size for a 1/8 x 27 NPT is letter drill R (0.339"), which I found to be very expensive and hard to get. The general consensus seems to be to use a 5/16" drill (0.3125) and sort of ream it out a little bit when drilling.
One problem I saw is that the fill plug is a 3/8" hex. I can get a hex socket on the plug but then it's impossible to get a ratchet or breaker bar on the socket because the rear storage compartment is in the way. I have a 3/8" L-shaped hex wrench and I tried to loosen it with that, but couldn't do it by hand. It's really tight and I will need a little persuader to break it loose.
The rear Y pipe is in the way of the drilling, so it will need to come off. I've been putting this off because of other projects and this is my daily driver so it needs to be running...
If I were going to add a drain plug to a transmission pan I would buy an oil drain plug. Then buy a nut to fit that plug, and weld it on or have a friend weld it on the inside of the pan.
If I were going to add a drain plug to a transmission pan I would buy an oil drain plug. Then buy a nut to fit that plug, and weld it on or have a friend weld it on the inside of the pan.
That's why I used the M18 O2 bung, the Toyota drain plug and gasket was intentioned as an engine oil drain plug. It's not a problem to buy gaskets or another plug if a person needed for some silly reason.
Cliff, not sure if you have already installed a rear diff plug yet but I saw this post on another forum and i thought it was pretty good for a rear diff install guide.
I see this plug is located at the rear left side of the diff.
That is my next project. From what I could tell, the hole needs to be 1/2" forward of the gasket surface and 1/2" to the passenger side of the casting line for a D36.
I'm using a 1/8 x 27 NPT stainless steel plug with a hex socket. The drill size for a 1/8 x 27 NPT is letter drill R (0.339"), which I found to be very expensive and hard to get. The general consensus seems to be to use a 5/16" drill (0.3125) and sort of ream it out a little bit when drilling.
One problem I saw is that the fill plug is a 3/8" hex. I can get a hex socket on the plug but then it's impossible to get a ratchet or breaker bar on the socket because the rear storage compartment is in the way. I have a 3/8" L-shaped hex wrench and I tried to loosen it with that, but couldn't do it by hand. It's really tight and I will need a little persuader to break it loose.
The rear Y pipe is in the way of the drilling, so it will need to come off. I've been putting this off because of other projects and this is my daily driver so it needs to be running...
If I was wanting a drain for the 700r4. I'd probably look around to see if someone makes a good aftermarket 700r4 pan with a good drain setup already built in.
I've read of people installing their own i.e. nut/bolt or weld. And some have no problems, but it seems like more people have problems with them then those that don't. Most of them with leaking.
I've run one for years without a problem. Locktite the nut and tighten well. My engine oil pan, and exhaust were always much lower than the pan. Never scraped the pan or bolt. It made tranny oil changes much easier.
Willie, thats because they dont have speed bumps on the quarter mile.
Cliff, Where on the pan did you put the drain plug. Mine is in the back. I am getting ready to do another, as pan is leaking.. Recommendations.
It's in the back. You can see the hole in the picture. I had some leaking and tried to tighten it but the gasket had compressed and the nut inside was spinning. The next project is to braze the inside nut.
Cliff, not sure if you have already installed a rear diff plug yet but I saw this post on another forum and i thought it was pretty good for a rear diff install guide.
I see this plug is located at the rear left side of the diff.
A D44 differential is thinner on the left side. The D36 is the same thickness on both side of the center bolt. The casting parting line is to the right of the center bolt so I went 1/2" to the right of that to have a reference line. My digital camera was being obstinate and not working during the modification (I found out later the batteries were dead), so no pictures. I realized during the modification that I will probably never use the drain plug since the drain interval called for in the owner's manual is 100K miles and my car has 123K after 29 years...
I get mine at advanced auto and put it in the rear or front close to the bottom. You gotta put gasket sealer around the inside and out than tighten.1 vette and 3 trucks done no problem.
I never had a leak, only around drain bolt but some Teflon tape fixes that easy
One problem I saw is that the fill plug is a 3/8" hex. I can get a hex socket on the plug but then it's impossible to get a ratchet or breaker bar on the socket because the rear storage compartment is in the way. I have a 3/8" L-shaped hex wrench and I tried to loosen it with that, but couldn't do it by hand. It's really tight and I will need a little persuader to break it loose.
I made a special wrench for checking the rear diff. I cut a 2" section of an allen key & welded it to a long 3/8 combo wrench, in fact you really don't need to weld it if the key fits into the box end good. Find a craftsman 47538 wrench.
I ended up brazing the inside nut to the trans pan. I'm not very good a brazing so I drowned the whole thing in JB Weld to make sure it sealed. No leaks now.
04-07-2015, 02:02 AM
Add a Drain Plug to Your 700r4/4L60/4L60E
The details are gross, speed bumps should be banned, but... it can happen 
