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E4OD, port on drivers side for trans temp gauge

35053 Views 63 Replies 34 Participants Last post by  CJohnson1
I'm working on putting in a trans temp gauge. Reading the forums, I see a lot of people referring to a port with just a bolt in the driver's side of the tranny as a good place to put the gauge. My question is, does anyone happen to know the size of that port so I can have any adapters I need ready to go before I start doing this thing.

Thanks.
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I dont recall the size, but I believe the temp sender just threaded right in with mine. Its been a lot of years, but i dont remember needing any adapters.
Nope, no adapters, just a little teflon tape and thread it in!
Port Location

Hello, long time lurker, first time poster. I was just wondering if the port you are talking about is the bolt that is shown circled in the pictures. Also, when I unscrew it should I be ready for tranny fluid to come out or isn't the fluid level up that high. Thanks, Derek.
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You may have to grind a little off the tip of the sensor, some of them are too long and bottom out.

That is not the best place to pull the tranny temp.
Ideally would be in the line going to the cooler.
But you probably know that.

The size is 1/8th inch NPT.

Not much fluid will come out of there. A rag will catch it.
Out of curiosity, why isnt that the best (or equally the best) place to put the tranny temp sender? Its were I installed mine becasue I wanted to know the actual temp of the tranny. Seemed to work... I was hittin 210 prior to my cooler/filter install and am hittin around 170 after.....
I run mine in the pan i want to know what the true temp is before going into the trans especially if your using a extra cooler they will drop the temp more then you think.
Out of curiosity, why isnt that the best (or equally the best) place to put the tranny temp sender? Its were I installed mine becasue I wanted to know the actual temp of the tranny. Seemed to work... I was hittin 210 prior to my cooler/filter install and am hittin around 170 after.....
From what I hear it is a dead end channel for a pressure test. So not much fluid flow passes by there. So basically measuring tranny housing temp.

That's just what I've heard though.
Your pan is the last place that sees the accurate temperature. Especially since it has to heat all of the fluid sitting in there.

The majority of your heat comes from the converter. If the clutch packs in the tranny are creating the much heat, it is too late, your tranny is junk.
Maybe the E4OD is different, but typically oil runs from the pump, to converter, cooler, then circulated through the tranny.
If you want to know what the fluid temp is running into the tranny, then you need to put it in the return line of the cooler.

It is more instant sampling the fluid on it's way to the cooler, If you want to prevent damage as quickly as possible the cooler will see the heat first, then through the tranny and finally the pan.
Measuring it in the pan means the entire tranny has already seen that temp. Realistically that is too late. You need to shut it down before the tranny gets that hot.

Just like an engine, the oil is pumped out of the pan, goes and does it's work and the last place it ends up is the pan.
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Hmmmm... interesting. That makes me want to put another gauge in the line and see the difference. It makes sense what you are saying, dont get me wrong. I think it would be worthy to test it though and see what the difference in temp is. It would help establish the most effective place to put the sender so ppl doing the filter/cooler install would not have to wonder or guess.... maybe I will pick up a cheap gauge in the next few weeks and give that a try....

Also, the dual tranny cooler set up makes a HUGE difference. Even on the trail in 90 degree weather on HOT rocks... my tranny never went over 180... can running a tranny to cold do damage?? (sorry for the hijack). Hoping this is info we can both (all) use.
That is actually another very good point. Seeing the temp in the pan does not indicate how hot the tranny fluid has gotten.

Tranny fluid starts breaking down at 180 degrees. It is good to know if the fluid it frequently getting hotter than that, so you are aware that you need to change it more often.

Anything over 120-140 degrees is warm enough to evap the moisture out of the tranny fluid.
Keeping it at 170 would be ideal.
Hmmmm... interesting. That makes me want to put another gauge in the line and see the difference. It makes sense what you are saying, dont get me wrong. I think it would be worthy to test it though and see what the difference in temp is. It would help establish the most effective place to put the sender so ppl doing the filter/cooler install would not have to wonder or guess.... maybe I will pick up a cheap gauge in the next few weeks and give that a try....

Also, the dual tranny cooler set up makes a HUGE difference. Even on the trail in 90 degree weather on HOT rocks... my tranny never went over 180... can running a tranny to cold do damage?? (sorry for the hijack). Hoping this is info we can both (all) use.
Ideally you want the transmission to operate at normal engine temps you want to run through the extra cooler first then your radiator cooler. It keeps the engine temps down and the transmission closer to normal engine temps
The return line atf going into your transmission and pan will not raise the temp vary much. What kills transmissions is heat witch breaks down the lubricating properties of the oil. which in turns brakes down your clutches That why they say to run a extra cooler and filter that atf is is a speed demon coming out to the cooler. It will drop the temp in a fraction of a secant. so if your putting 180 atf into your pump and converter what do you have converter and pump melt down.
I had a nice bar graph posted in FG's trans thread before, but ATF normally doesn't start losing it's life until about 210F.

180F-190F is prime operating temperature for general use automatic transmissions, and about 150 is prime for racing applications.
what gauge to but? do they have both electric and mechanical for trans temp? or what? thanks guys
I've got my temp gauge in that port - I didn't even use teflon, just stuck it in there, absoutly no leaks. I'm going to move the sender - I believe that gauge reads high. You dont want to read the temp of the fluid in the transmission, I'd read the fluid temp after it gets cooled so you know how your trans is doing. You dont need a gauge to let you know when you beat on it, the temp goes up. What is important is the fluid comming back into the trans.
I think you need to think about what you are saying again. We need to see the max temp of the fluid to know whether or not it is breaking down, who cares how cool it gets, is its at 250 degrees before the cooler and then it comes out of the cooler at lets just say (not realistically) 140 degrees, would you ever know if you have smoked the fluid or not?
:stupid

Your gauge could easily say 190 which would be prime, and you could have 250 degree fluid coming out which means the fluid is breaking down, and you'd never know it.
I think you need to think about what you are saying again. We need to see the max temp of the fluid to know whether or not it is breaking down, who cares how cool it gets, is its at 250 degrees before the cooler and then it comes out of the cooler at lets just say (not realistically) 140 degrees, would you ever know if you have smoked the fluid or not?
My thoughts exactly..... my goal is to know how hot my transimssion (and fluid) are getting. That is where the damage could occur. If the temp of the tranny is dangerously high, I dont care if there is a cooler or not.... something is wrong and thats what I want to know. When I did my tranny fluid change, I could see where the sensor is located in the transmission. It looks like a pretty good spot to me.... the pressure port location is not in the pan, it is in the tranny housing, pretty high up on the tranny comparatively. I would think that the transmission itself would be the optimum place for the sensor, with the output being the second most desirable (with it mounted very close to the tranny) and the cooler return being the third.... I have left mine in that pressure port because from what I can tell with the visual inspection of the opened up tranny, thats about the best place for it....
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