Hey everyone,

So I've got the chance to buy a BeCool aluminium rad (Part #35008 on Summit http://www.summitracing.com/int/part...5008/overview/) for cheap.

It's for a manual transmission, so none of the ATF will circulate through the rad like my stock rad.

I do have an external transmission cooler from Oregon Performance Tranmission... Hayden Transaver Plus 24,000 GVW Transmission Cooler heavy duty: Oregon Performance Transmission - Rebuild Parts for 700R4 4L60E 4L80E E4OD 4R100 47RE 48RE & More

Because the aluminium rad is for a manual transmission, Is it an issue?

I don't see why I would need to circulate my tranny fluid through BOTH the radiator AND then through the transmission cooler... but I want some input.

 

A good size cooler in front of the radiator is plenty. It looks like the cooler you have is plenty big - no need to run the fluid through the radiator.

 

My input is that the transmission is going to run quite a bit hotter without the cooler in the radiator. The radiator cooler is there for a reason, and that reason is that it's needed for cooling. It does a large part of the cooling of the transmission.

 

Agreed, the stock rads required a trans cooler to be internal with the radiator... but they never had an external transmission cooler from factory (in addition to the internal rad one).

If I do buy a rad with an internal trans cooler, then what's the point of having an external cooler as well?

Seems a little redundant if you ask me, but I'm curious on your input.

And yeah, I bought a big one just for the extra cooling. Temps are what kill transmissions, so I went a little overkill because the price was right.

 

Many trucks have both coolers. It's because they need the additional cooling the second cooler provides.

Also, the air to oil cooler does almost nothing when backing up. There is little to no airflow over that cooler when in reverse. The engine radiator always has a supply of cool water to cool the ATF.

 

Besides the airflow issue mentioned, water has a much higher specific heat (and thus cooling capacity), so the integral cooler is more effective in a smaller package. If you're not towing, though, a sufficiently large air-to-oil cooler sitting out in front of the radiator should be fine.

 

Both are very valid points... Especially the reverse comment - the little details/things are the ones that are often missed!

I don't plan on towing anything, but it'll become the biggest baddest truck in the family... so I assume I'll get roped into towing something for someone.

So while we're on the topic of having both in a truck...

What's the proper way to hook them up?

A) Tranmission exit/return --> Radiator --> External trans cooler --> Transmission enter/supply ?

B) Tranmission exit/return --> External trans cooler --> Radiator --> Transmission enter/supply ?

 

You will probably get 4 answers from 4 different people. The external cooler I installed recommended going to external cooler first then routing through radiator.

 

A) would be the ideal path for maximum cooling. Transmission exit -> Radiator connector nearest the lower radiator hose, then radiator connector farthest from lower radiator hose -> external cooler, then external cooler -> transmission return.

This will give you cooler overall temps, as the radiator will bring the ATF down to around engine coolant temperature, then the air-to-oil cooler will bring it down further.

B) would be ideal if you're trying to maintain as consistent a temperature as possible without going under or over - the air-to-oil cooler would do whatever it does (and cool it enough that the radiator cooler can always keep up), then the radiator cooler would get the fluid to around the same temperature as the engine coolant, but no lower.

I plumbed my truck with configuration A. If you live in an extremely cold climate and are worried about over-cooling and viscosity increase, you may want to go with B.

 

I recommend the opposite. The cooling system is FAR more efficient when going from the transmission (the front of the trans is the hot fluid leaving the trans) to the radiator, then to the aux cooler, then to the rear of the trans.

Not true at all. The cold side of the radiator is nowhere near engine coolant temp in cold ambients. In hot weather when the engine is working hard it can get within 15-20F of engine coolant temp, but it never gets that hot. If the cold side of the radiator was the same temp as engine temp, why have a radiator?

In cold weather the cold side of the radiator is usually right around ambient temperature, even when the truck is warmed up. I've measured this as cold as -40F. The cold side of the radiator hovered around -30F once the truck was driven enough to warm it up. How well will -30F coolant warm the trans fluid?

If you want to warm the trans fluid in the winter, block the cooler with cardboard, or install a thermostat to bypass the cooler when the trans is cold.

 

That's some really good info mark!

Thanks I appreciate it.

 

The fluid in the radiator is engine coolant. The temperature at the cold side of the radiator is the temperature of the engine coolant supply to the engine. It's not the coolant return (high) temp that you measure with the gauge (and which the thermostat uses to control flow), that's true. But the temperature of the engine coolant at the outlet of the radiator is the temperature that is relevant from the perspective of the transmission cooler. And in the limit, the transmission fluid can approach this coolant temperature.

The reason I specified that the line from the transmission should run to the side closest to the water outlet from the radiator is that this sets up the water/oil cooler in a cross-flow configuration, which maximizes the heat transfer effectiveness.

Good info on coolant temperature at extremely low temperatures. I was speculating as to why anyone would want to set up in configuration "B" and that was the only thing I could think of - guess that isn't much of a use case either.

 

I also own a 2008 Crown Vic, the Transmission Cooler is attached/part-of the condenser in front of the radiator. The aftermarket coolers are not large enough for the transmission to cool, you will need a bigger cooler, but it does not need to be attached/part-of the radiator.