Tranny Coolers

[tuckerd1]

What size cooler would I need to replace, or add to original cooler, to completely eliminate using the radiator cooler from cooling the trans? Anyone ever done this?

 

[Agnem]

I would think a couple of B&M super coolers would do it.

 

[subway]

i thought it was a good idea to have at least part of the tranny cooler in the radiator to help regulate the tranny with the engine. that way it would help it warm up faster and stay a more consistant temp........cant say for sure though i alwsys stuck with stick shifts.

 

[jauguston]

It is not a good idea to bypass the cooler in the radiator. It is also a transmission heater in cold weather. I think you will find that the makers of aftermarket trans coolers do not recommend bypassing the cooler in the radiator.

Jim

 

[tuckerd1]

i thought it was a good idea to have at least part of the tranny cooler in the radiator to help regulate the tranny with the engine. that way it would help it warm up faster and stay a more consistant temp........cant say for sure though i alwsys stuck with stick shifts.

That is one of the reasons I asked. Your comment makes sense to me and I had forgot about this part. It takes about a mile of running before my trans warms up on cold days as it is.

 

[subway]

so are you looking for more protection, they say the bigger the better for coolers. back when i had my old dodge i added a temp gage (stock tranny cooler) and found it got the hottest sitting in traffic but hardly bumped up when hauling a load. granted it was a slant six so i wasent pulling anything big with that at all, but i would reccomend a temp gage to keep an eye on it either way. i just used a cheep engine temp gage and a couple of pipe fittings cost about $30 for the whole set up.

 

[Mr_Roboto]

I have to ask why you want to bypass the in-radiator cooler?

Do what you have to do, but that little cooler in the radiator does a lot of work, and at low speeds will cool where an fluid-to-air cooler won't.

As far as the cooler heating the trans fluid in cold weather, it isn't going to happen. The coolant in the radiator is going to be the same as the ambient temperature until the thermostat starts to open, and even then the bottom of the radiator is going to be the coldest part, and colder than the trans fluid.

 

[tuckerd1]

I have to ask why you want to bypass the in-radiator cooler?

Really the only reason is to move the lines from underneath the serpentine belt just in case it breaks. I have had it do some serious damage to the lines when it comes off. Broke the trans cooler from snatching on the rubber hose once. Left me stranded. I got lucky because there was a factory recall on the belt tensioner, or idler, cant remember. Ford paid to tow the truck and do all the repairs.

 

[Agnem]

I'm not sure I buy this "it's a transmission heater in the winter time" deal. I've heard that from more than one person. How can that be, when the first several miles could be driven without the thermostat on the engine opening, and the water in the rad could be ice cold. Also, the radiator can be so effective that the coolant returned to the engine can be near room temperature. I think the torque converter does a pretty wonderfull job of heating the fluid in the winter just fine, and in the summer a little too fine.

 

[Mont91]

There was a TSB on the tranny cooler by-pass hose. This is the heater hose that T's off and goes down to the radiator bottom tank. The fitting on the radiator has a small hole in it to regulate flow. The purpose of this hose is to provide coolant flow to the tranny cooler with the thermostat closed. My understanding is that it was for keeping the tranny ffrom over heating. I can see this at 20 30 or 40 below zero with the heater running full blast idling along(driving around town or pasture and such) the thermostat would not open but the tranny would still build heat. And there was a TSB about adding a ford supplied plate cooler for additional cooling for the tranny and it was to be placed in the return line. I reread this pacement statement a couple times.

 

[subway]

interesting so where do i find this info at? i never thought that the in radiator cooler would make a tremedous difference i just thought it would help keep temps in check. a fliud cooler like in the radiator should be much more effiecient than a air cooler. i would agree when i saw the temps rising in my tranny it was from sitting and the torque converter warming it up. not from any light towing i did with it.

 

[Agnem]

I know they never used that set up with any of the 83-86 trucks, so I wonder why they felt it necessary all of the sudden?

 

[sle2115]

I always have to wonder as well that in a cooling mode (and I know the physics of liquid to liquid versus air to liquid) how much more efficient could it be cooling a transmission with 200 degree coolant versus 80 or so degree air? Yes, the liquid to liquid is more efficient and transferring heat, got that, but my trans temps without the radiator cooler on my 79 Chevy that made over 500 HP was 20 degrees cooler when hooked to a liquid to air versus using the radiator cooler. I also had return/send line temp gages on the transmission. We ran a 3000 RPM stall converter and saw much better temps by NOT circulating ATF through the 200 degree radiator. I could only imagine that these motors REALLY cause trans heat because of the torque multiplier that is factored into torque converter slippage. High torque = higher slippage when all else remains equal. My engine didn't make REAL horsepower until about 5500 RPM, versus these motor that make it at less than 1/2 of that which causes more slip in the TC.

Also, no one will ever convince me this is to work as a heater either. If you don't believe me, watch a trans temp gage and a coolant gage - even if the coolant temp is taken in the cylinder head, the trans temp in every automatic I have ever had rose faster than the coolant temp - at least to operating temperature. So how could 100 coolant help heat ATF that is 110 degrees - I was born at night, but not last night...

 

[Mont91]

The TSBs are on the Montana Online Library site, but you have to have a password given to you by your local Montana library.

I think the cooler in radiator is the best fits all solution there is for the auto makers. My '97 Aerostar has both from the factory as due many other makes and models. The chevy diesels of old ran the engine oil thru a cooler at the "top" of the radiator and the tranny cooler at the "bottom" of the radiator and still cooled the engine.

The coolant at the "bottom" of the radiator would not be 200 degrees but your point is a good one. Seems the biggest problem with the air coolers is garenteeing air flow acrossed a properly sized cooler. The second biggest is a properly sized cooler, or vise-versa. The cooler/fan kits that you mount any where seem an excelent solution.

 

[Mont91]

The coolant bypass hose was for the E4OD. Possibly they generate heat faster than the C6 did or maybe they figured out why some trannys were burning up in cold weather.

Anybody have or have had a temp guage on the bottom radiator hose?