Hi folks, I am looking to tap into the tranny oil on my 98.5 47RE transmission. I am unsure where to thread in the gauge temperature probe. I would rather not be reading oil temps after it has been though the cooler and is re-entering the tranny. I was thinking it would be better to read the hot oil as it exits the tranny. No?

 

I was under the truck today looking around for a test port plug. On the RH side I see these two plugs as shown in the photo. Am I even on the right track here? If so, which one is preferred? Thanks, Keith.

 

Edited October 12, 20195 yr by keithb7

The best place to read from, according to your needs, is spliced into the front line coming out of the transmission.  It is the hottest at that point...before it goes into any cooler.  The ports in your pic are for pressure readings in different gears.  I used to have mine hooked up there and it gave me lackluster readings.  But now I have it spliced into the line mentioned above and I get very proactive readings now.  I simply cut the line and spliced into it with half inch compression fittings with a Tee to screw in my temp sensor.  I can take a pic of it tomorrow when the sun comes up if you would like. 

This is the line, on the side of the engine, before it enters the first cooler. 

 

 

 

1 hour ago, Bullet said:

I can take a pic of it tomorrow when the sun comes up if you would like. 

 

Yes please pic.

...I bought an oversize pan and only benefit I've seen is trans fluid takes longer to get hot, but getting longer to get hot works out pretty good when towing trailer on grades.  

 

(Hit send the same time ibmoble posted)  

Edited October 13, 20195 yr by 015point9

11 minutes ago, 015point9 said:

 

Yes please pic.

...I bought an oversize pan and only benefit I've seen is trans fluid takes longer to get hot, but getting longer to get hot works out pretty good when towing trailer on grades.  

 

(Hit send the same time ibmoble posted)  

OK...I'll take a pic and post when I wake up tomorrow am.  It is similar to what @IBMobile just posted...the difference is that mine is closer to the transmission right after the line exists the tranny.  IBMobile's is a little further down that same line closer to the heat exchanger.  Mine no longer has a heat exchanger since I put the compound turbos in.  But both are the same in regards to trans temp right out of the hot line of the tranny.  I'll post a pic of mine tomorrow am.

I like having the temperature of the oil reading from a probe in the pan. That is the oil that the pump is drawing from, and in my eyes, that is the oil temperature that is relevant. The temperature exiting the trans is directly after the converter. Yes it's going to be much warmer at this point, especially in a non lockup situation. However it's not headed back into the trans; it's headed to the cooler. Most of the trans doesn't see this hot oil.

 

Just my two cents, take it for what it's worth.

I think pan temp isnt a bad place. Then you know its running cool and is cooling well.

 

Would be cool to see temps directly from the tourqe converter before it enters the heat exchanger on the block.

I took pics of my setup like @IBMobilebut

can't seem to get it downloaded to here.

 

When you temp it coming right out of the tranny you get the temp of the fluid at its hottest which is what I prefer to know.  If you are blowing 300 degrees out of the hot pipe, your pan temp sensor would never let you know that.  Meanwhile you have already cooked the trans fluid.  The hot pipe is a more 'what's going on right now' reading whereas the pan is more of a 'what has been going on recently' kinda reading. 

I'm torn weather I think the hot side of the trans is info worth knowing.  If the cool side in the pan gets hot then theres for sure serious problems.

1 hour ago, Evan said:

If the cool side in the pan gets hot then theres for sure serious problems.

This was exactly my thoughts on it...and too late to prevent any serious problems. 

19 hours ago, Bullet said:

I took pics of my setup like @IBMobilebut

can't seem to get it downloaded to here.

 

When you temp it coming right out of the tranny you get the temp of the fluid at its hottest which is what I prefer to know.  If you are blowing 300 degrees out of the hot pipe, your pan temp sensor would never let you know that.  Meanwhile you have already cooked the trans fluid.  The hot pipe is a more 'what's going on right now' reading whereas the pan is more of a 'what has already happened' kinda reading. 

 

 

  Case in point, When the torque convertor lock up failed in my transmission I noticed the temperature elevated from a cruising normal of 160°-170°F to 190°F and when going up long 6% grades, 5-8 miles long, the temperature would rapidly increase from 190°F to 250°F.  After stopping half way up a grade and running the engine with the transmission in neutral the temperature would keep increasing, sometimes to over 280°F before it would start to cool.  It would take up to 20 minutes to cool to 190°F.

   If the temperature probe was in the oil pan I would have never seen that rapid temperature increase due to cooling from the heat exchangers and temperature dilution when mixed with the cooler fluid in the pan. There could have been a good chance of the transmission being cooked before the temperature sensor in the transducer saw the overheat problem and turned the warning light on in the instrument cluster. 

  NOTE: The temperature sensor is in a part of the valve body, just before the governor solenoid, and sees very little fluid flow.   

That's very much the occasion I hope to catch and prevent as well.  I have over $5k in my tranny so I want to know what's going on with it in real time. 

Fair enough, but I don't need to watch temperature to know if my converter is locked.

I agree i know exactly when or if my converter is locked temp gauge not needed to know