Trans cooler

[94GMC2500]

The trans goes to a good sized cooler in front of radiator but not connected to the radiator trans cooler. I put new filter in this morning pan was spotless inside so I assume someone else has had the pan of not to many years ago.

I went for a easy 20 mile ride not towing anything and trans temp said a little over 200, in 85 degree muggy weather. Trans temp gauge sender is in test port on side of trans.

I held a thermometer on a stick on the bottom of pan and it said 185 just sitting there idling in park for about 15 minutes.

The images show the normal water temp driving it easy and the trans temp from this mornings easy drive.

Do the factory coolers plug easily? The inside I mean.

[JohnC]

Mine was definitely connected to both.

[94GMC2500]

I drove truck again to day, just a normal drive, not towing anything, 94 and humid out.

Trans temp said 210, I crawled under with a temperature gun and checked side of trans, 202 degrees, side of pan 185, hot side of cooler in front was 185, cool side of cooler was 176.

The sender is in the test port, is it better to have it in the pan or test port?

[DmaxMaverick]

What does the IR temp sensor say about the location of the test port? The sender could be indicating non-fluid heat, which is OK. Part of the fluid's job is to remove heat, which it appears to be doing.

It is better in the pan or the outlet to the cooler, but doesn't matter where you put the sender. NONE of the temp data is good for anything other than tracking trends. Senders and gages are notoriously inaccurate, but should be linear with actual. As long as the value is linear with actual conditions, assign that as "normal", and track the trend from there. Or move the sender and feel better about it.

[94GMC2500]

I am going to add another cooler since I have one laying here and move sensor to the pan and it is what it is I guess.

[DmaxMaverick]

I would suggest doing one at a time. First, move the sender. See what you really have. Then, add the additional cooler to maximize the cooling ability. Doing both will not tell you what was the problem, if there was a problem.

[Robyn]

In past years when I was towing I had a gauge reading the fluid temp at the inlet of the cooler and a second gauge reading the temp at the tranny return port.

Temp of the fluid in the converter is the important issue.

If the converter is COOKING the fluid to 220-250 F but your cooler is bringing the temp down to under 200 F the cooler is working, but the fluid is still being fried....

Are you sure the converter lockup is functioning ???


Snap a piccy of the tranny cooler that's there now and post it please.

The test port is just that...A pressure test port.... and it is the end of a passage.

You need the temp sender in an area that sees fluid flow and not a place that is surrounded by metal in close proximity (Port passageway)


Get your setup so the gauge sender is in moving fluid...

The pan is nice....but as I mentioned having data on what the temp is pre cooler and post cooler is a good thing...