Auto Meter Gauges, Electrical or Mechanical?

[Mtn8er]

Glacier would be the one to know for sure.

But yeah I see the conflicting answers because technically, I think the fluid in the pan is the fluid that was JUST at the aux cooler so technically, its been cooled down. But thats just my assumption, Glacier knows the exact route the fluid goes.

Oh ok, hopefully he'll look at this thread again.

 

[Maniak]

As I understand it, the fluid is the pan is the fluid that came from the cooler and went across the hard parts.. It then goes through the VB to the converter (which makes it the hottest) and then goes out.

The test port doesn't get flow so its not that accurate..

I use pan temp since that is what is going through the VB and just went through the hard parts..

I've seen 195F on stop/go traffic at 105F+ ambient temps (the pan temp was 130 even before I started the truck).

With 90F temps and the 2nd plate cooler + aux filter I've been seeing 165F max temps which is 15-20F lower than I was seeing with the cooler configuration.

Even with the occasional 195F temps in the pan the fluid never smelled burnt or changed color. I use Mobile 1 synthetic multi vehicle ATF (I'm running a 700r4 trans with a stall speed over 2500rpms).

my sender location is on the drivers side of the pan. It isn't a problem when draining. It just like imports that have the oil plug on the side of the pan.. Once you learn where the fluid goes when you open the plug you don't make a big mess.

~Mark

 

[Mtn8er]

As I understand it, the fluid is the pan is the fluid that came from the cooler and went across the hard parts.. It then goes through the VB to the converter (which makes it the hottest) and then goes out.

The test port doesn't get flow so its not that accurate..

I use pan temp since that is what is going through the VB and just went through the hard parts..

I've seen 195F on stop/go traffic at 105F+ ambient temps (the pan temp was 130 even before I started the truck).

With 90F temps and the 2nd plate cooler + aux filter I've been seeing 165F max temps which is 15-20F lower than I was seeing with the cooler configuration.

Even with the occasional 195F temps in the pan the fluid never smelled burnt or changed color. I use Mobile 1 synthetic multi vehicle ATF (I'm running a 700r4 trans with a stall speed over 2500rpms).

my sender location is on the drivers side of the pan. It isn't a problem when draining. It just like imports that have the oil plug on the side of the pan.. Once you learn where the fluid goes when you open the plug you don't make a big mess.

~Mark

Oh ok, so no on the test port. So between the fluid in the pan and the fluid running to the cooler, the fluid is going to be the hottest in the line running to the cooler? Wouldn't you want the sender there then? Since the fluid is at it's hottest peak?

 

[Maniak]

Thats the ongoing debate. Some people believe to watch the temp in the pan, others in the output of the trans.

I went with the pan method since that closer to the temp the transmission is seeing most of the time. You also need to look at what is "normal" temp in your transmission to see when it is getting hot compared to normal.

~Mark

 

[Mtn8er]

Well I emailed Auto Meter directly about this and here's the response I got...

Michael, ideally the best spot is in the test port, this measures the
temp from the torque converter. If you are not able to put it there,
then you can use the HOT line going to the cooler.

Thanks, Eric
Tech Support
1-815-899-0801 Tech Line
1-815-899-7000 FAX

I'm so confused now lol

 

[Maniak]

Now you see the delima.. Every has different opinions.. BowTie overdrives likes the pan, autometer wants the hottest spot.. I use the pan, I know a few others use the pan but many put it in the port on their external filter (output line from the trans)

The only consensus I've been able to find is that no one says to put it in the return line.

~Mark

 

[Mtn8er]

Now you see the delima.. Every has different opinions.. BowTie overdrives likes the pan, autometer wants the hottest spot.. I use the pan, I know a few others use the pan but many put it in the port on their external filter (output line from the trans)

The only consensus I've been able to find is that no one says to put it in the return line.

~Mark

Yeah...if you think about it (which I have long and hard), it almost makes the most sense to have it in the pan. Wouldn't you want to know what the temperature is that's getting ready to go into the tranny and through all the parts? Honestly, after it leaves the torque converter...you would think, who cares what the temp. is because it's going to be constantly changing (lowering in temperature) from there on as the fluid goes through the cooler(s) through everything else and back to the pan. I personally would think that knowing what the fluid temp. is before it goes through the tranny would almost be the best (putting the sender in the pan).

If you have a high temp. reading before it goes through the tranny then you would know you need to upgrade your cooling system because it's not cooling back down to normal operating temperature. I don't know, that's just how I look at it. Seems like it just comes down to personal preference. Once you get to know what the average reading is, regardless of where the sender is, you'll know when it gets hot.

 

[Tom Brown]

...if you think about it (which I have long and hard), it almost makes the most sense to have it in the pan. Wouldn't you want to know what the temperature is that's getting ready to go into the tranny and through all the parts? Honestly, after it leaves the torque converter...you would think, who cares what the temp. is...

I think I understand your reasoning. It makes sense. I, however, have a different view.

The reason I want to install a trans. fluid temperature gauge is to check the hottest oil temperature. The reason I wish to monitor the hottest oil temperature is because heat is what causes ATF to break down. ATF failure is what causes transmission failures.

In other words, I don't care about the coolest temperatures. I care about the worst case temperatures. If the oil is going to break down, it's going to break down from the extreme heat, not the averaged out pan temp.

I feel the same way about engine oil temps in a turbo environment. I've been told by people I trust, and I certainly believe them, one of the main reasons turbo engines don't last as long as N/A engines is because of oil break down.

A friend of mine has managed to get 1000+ hp big block GM engines to last a good while bolted to jet pumps and cranking out high RPM and big power numbers for indefinite periods. He managed to track down his cam reliability issues by watching the oil temps at the hottest place. This caused him to discover that he needed a huge oil cooler. Larger than was available, in fact. He has huge coolers custom made now and his reliabilities have gone way, way up.

.... just another perspective. No disrespect intended.

 

[Maniak]

I understand that thinking too. I don't think either method is perfect but each shows you some of the information, its just how you use it. You almost need to have two gauges. One for the temp that the transmission sees and another for the hottest temp the fluid gets.

Since I can't see the hottest I use synthetic Trans fluid to try to mitigate(sp?) the hottest temp the fluid will see (torque converter to cooler). I also do a pan drop fluid change every other oil change (at least during the summer) to also help keep the trans alive.

I'm going to do a few UOA on the trans fluid this summer to find out if I am breaking down the fluid (maybe I can cut down on my fluid changes).

~Mark