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Best place for 4L80E temp sender?

Yachtcare

Yachtcare

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Hey gents, been searching around and cant find any info readily available, here, or elsewhere. Anyone added a temp gauge for their 4L80E, where did you put the sender? Dont have the scratch for an aftermarket pan just yet, or I'd put it in the drain plug there. Wondering if there's a preferred spot on the tranny itself? Thanks.......
 
I was going to try drilling my stock one after the Derale I bought didn't work out. Not sure about clearance. The Autometer I bought came with the pan drill kit.
 
On the drivers side of the tranny there is a 1/8" npt pipe plug where they measure pressure. You can't see it, you have to feel around for it.

Leo
 
NVW said:
On the drivers side of the tranny there is a 1/8" npt pipe plug where they measure pressure. You can't see it, you have to feel around for it.

Leo
Click to expand...

It is right behind the shift linkage. It's a tight fit but you shouldn't have to remove the linkage.
 
I always used to put them in the cooling line, measuring out, but the trans shop owner convinced me the temp going back in was what was important. He said that whatever temp you are feeding it is what matters, not what is going out to be cooled. Apparently if it's getting too hot the cooled fluid coming back will maintain it. Made sense to me.
 
I put mine in the stock pan using a Derale trans pan drain plug kit 13010 which is designed for a sheet metal style pan. I found only one real suitable place on the side of the pan in the forward deep part that kept it from sticking down and clear of the exhaust crossover pipe and also kept it clear of interference inside the pan. On the forward passenger side there is a step in on the corner the plug kit fits nicely in the lower portion of that step, it's hard to describe so I can take a pic if you like.

As far as I am concerned I would rather know how hot my trans is getting not how cool the oil is feeding it, should you have a cooling issue then this will be reflected in the temp of the oil coming out of the trans and IMHO the pan is the best place to measure that.

Cheers
Nobby
 
regarding the pressure port, I found that to be slightly slow in changing to what was happening real-time, the biggest consideration is the type senting unit used. pressures can exceed 300psi, keep that in mind if using that port.

I used a brass "T", barbed ends and 2 pieces of hose to go inline. make sure to ground the "T" or gauge wont work.
 

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nobby said:
As far as I am concerned I would rather know how hot my trans is getting not how cool the oil is feeding it, should you have a cooling issue then this will be reflected in the temp of the oil coming out of the trans and IMHO the pan is the best place to measure that.

Cheers
Nobby
Click to expand...
That's what I thought, but the trans shop owner was able to convince me otherwise. The temp feeding in is essentially what the trans is operating at, basically as long as the cooler is able to remove the heat and keep up, then it will maintain the transmissions operating temp. Once you lose the ability to cool, then the trans will cook itself. So it makes sense to me to monitor that you are still cooling it. The temp coming out is supposed to be higher, that's why it is sending itself to the cooler. I guess either way, in or out, you can monitor any fluctuation in temp that you may need to worry about. I don't know what measuring the temp at the pan is actually giving you, as far as circulation is concerned. I'd guess it's a pretty reasonable way to measure the temp of the trans overall, and again you can monitor for fluctuation. But you may at the pan be measuring the same thing, cooled fluid that just arrived back at the pan; I don't think it's hot fluid that's waiting to go out to the cooler. Like I said, I don't know where it is in the circulation path when it's in the pan. Can't be just sitting there.
I don't know enough about trannys to claim to know much, I'm just relating what the tranny shop owner told me.

Docdray, which line did you choose?
 
Sorry was away for a few days. Thanks for the responses.
My gauge is electric, slipped my mind to mention that.
I kinda like docdray's set up. Thinking it wouldnt be too tuff to split the line right down beside the tranny itself. Might get the most accurate reading there as it comes strait out of the tranny, as opposed to measuring from the pan. I can also leave it there when I get the new pan as well. One less thing to do twice:)
My philosophy is to know how hot the tranny is getting. By observing under normal load, a base line can be established to compare to when towing. Now all I have to do is track down which line is sending to the cooler........and tackle it over the weekend.
Thanks again.....
 
I'd put it in the test port, especially if your going to get a pan later. That way you dont create a week point in your cooler lines for a possible leak later, even though the pressure is minute.

Another reason I dont like it in the cooler line is, if you put it before the cooler your just reading torque converter temp, if after the cooler the oil temp will be lower than the actual sump temp for the most part.

A sender in the pan you get a reading of how hot the oil is that is feeding your transmissions parts, main thing being seals/o-rings and fluid that heat effects most. In the pan the temp will be hotter than the cooler line because of heat created from the pump feeding engaged clutches/lube circuits plus all the friction from gears meshes under load and gear changes, all this oil drains back to the pan and recirculated uncooled.

If your good with a welder or have a friend, just cut a steel 1/8" pipe union in half and weld one half to the pan, drill and your set. I've even done them on the truck before(do it when its full of fluid, so its submerged to help cool it and no oxygen for a fire inside), have your sender ready, let the fluid wash the shavings out when you drill, stick the sender in and your done.

Here's the best pic I have, the temp sender is in the upper right, the drain plug(1/4" pipe) was made the same way also. You can also see the sender in the pressure port(upper center) for my pressure gauge.
 

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I would go for the pan install. That is the temperature the tranny itself is seeing and running at.

... Unless you are towing it will never heat up in normal conditions. Really the only time mine heats up is when it is sitting on the torque converter and not locked up in mountain driving with a load/trailer.
 
Well, more good info, and things to consider. Here's a thought, does the ecm on an OBD I vehicle read tranny temp from a sensor someplace? IIRC, I read somewhere that it did, but that may have been for OBD II. Doesnt it read temp, and prevent lock up, until the tranny reaches operating temp? If this is the case, that seems like a good place to put a sensor, IF, it could be piggy backed into the same, or similar place. Anyone know where that factory sender is located?
 
Yes, there is a factory trans temp sensor in the pan, if you have a scanner you can compare it to your gauge. It is wired through the round big gray plug on the drivers side, it is made into the internal trans wiring harness.
 
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