Cooler experimenting

[dirtautoguy]

On my 1996 k1500 with a 4l60e I have converted it to electric fans from a newer chevy and they work great.

some minor issues I have come across is the trans cooler. I currently have it running to the radiator cooler and then exiting to a cooler in front of the axle condenser and then back to the trans. I have found that with the electric fans the trans cooler does not get air flow and the trans gets warm.

I most recently discovered this towing my camper on a crappy road going slow. The motor stayed very nice temp of about 193 but the trans was trying to get over 200. I flipped the manual override on my fan and it dropped the trans to 150 in very short order.

this made me do some thinking. If the trans cooler had its own temperature controlled fan maybe I could remedy this problem for slow mountain driving. So I got a 9 inch fan and mounted to the front of the cooler as pusher fan.

on the highway it hasn’t made any difference in temperatures they stay nice and cool. We went for a slow ride on a really bad road up a logging road last night and I tried it out. (Currently it’s just wired to a switch but will be temp controlled later). Anyway it’s all up hill one way and down hill the other way. I had the truck in manual 1st puttering at about 800 rpm and the trans climbed eventually to 180. I switch the fan on and it took a good amount of time but it only dropped to 175.

after we got out of the crappy road stuff I put it in OF and mostly coasted out at about 15mph fan off and it dropped to 145 in quite quickly.

so I know a pusher fan is not
Ideal but I believe it will work but I’m not sure what to think of this trend.

Either my fan really sucks in the way that it shouldn’t Doesn’t feel like it?

I read somewhere that at certain times with the torque converter the trans will not send fluid to the cooler. But I can’t find it now and I can’t find anything else about it.

my other thought to was maybe in OD I had a higher rpm which moved more fluid to cool off?

am I missing something here? I don’t think anything is wrong I just am trying to understand the trends so I can keep an eye on it.

 

[Pinger]

I read somewhere that at certain times with the torque converter the trans will not send fluid to the cooler. But I can’t find it now and I can’t find anything else about it.

.

Is this >> https://www.sonnax.com/tech_resourc...in-the-pump-pr-converter-cooler-lube-circuits what you are referring to?

 

[L31MaxExpress]

FWIW....180°F is not that hot. I see around 200-210°F backing my travel trailer uphill into the parking lot and manuvering it into place where I store it at my shop. 2,800 stall builds some heat in it fairly quickly, especially in reverse. Reverse is geared about like 2nd gear in a 4L80E/4L85E.

I have the Sonnax valve above, never have installed it. My line pressure is higher than factory in my 4L85E.

 

[dirtautoguy]

That is the article I read and it makes sense. It sounds like the 60e does let it go to the cooler but maybe to a lesser amount than when the valve is “balanced”.

sorry if I was vague. I’m not worried about it being at 180 I’d just prefer it stay under 200 but I was trying to test my setup to see if it worked. More than anything

Before I got the aux cooler set up it ran about 170 just on the highway. After the cooler it generally runs about 145-155 which was cool to see that it’s working

 

[dirtautoguy]

I did some more experimenting with it, and found that if I put it in 2nd and used the brakes more the trans stayed about 10 degrees cooler. I also let the trans get hotter to about 195 and then turned the fan on and it would cool it down to 177 untill I got out on the road. I have decided that the cooler I have must be a self regulating type that only flows a certain amount at certain temperatures. And the fan can only cool to that much.

But on the highway or At least faster speeds there is a lot more wind plus the cooler in the radiator probably cools a lot more as well making it run cooler.

so when I set the fan up to be temperature controlled I’ll probably set it around 195-200 and go from there.

 

[kenh]

The in radiator "cooler" can be an oil warmer in some situations.

Ken

 

[Pinger]

The in radiator "cooler" can be an oil warmer in some situations.

Ken

But not until the engine thermostat opens. Until then, the trans is heating the engine coolant sitting in the rad.

 

[kenh]

But not until the engine thermostat opens. Until then, the trans is heating the engine coolant sitting in the rad.

True enough!

Ken

 

[studigggs]

But not until the engine thermostat opens. Until then, the trans is heating the engine coolant sitting in the rad.

On my '90 350 the heater core is always flowing, so not true for all GMT400s. If the engine is running, then there is always circulation from rad to water pump, through block to Heater core and back to Rad.

 

[Pinger]

On my '90 350 the heater core is always flowing, so not true for all GMT400s. If the engine is running, then there is always circulation from rad to water pump, through block to Heater core and back to Rad.

Maybe later models do the same?
One observation form last week though. Faffing around doing LPG calibration I had to hold the engine rpm steady at 3000 rpm with my hand directly on the throttle shaft. The engine wasn't stone cold but not hot enough to open the thermostat. The blast of air from the fan was pretty damned cold. Not a lot of heat in the coolant rad at that point!

Looking at the plumbing though, pretty sure the heater returns its flow straight back to the engine on later (mines a 1999) models. Others here will know better is that is true or not.