Size of Trans Cooler required for 1985 32 ft Elandan 454 with th 400 trans?

stopngo · October 11, 2015, 06:15 PM

Is this a the bigger the better type thing or is there a size beyond which no advantage??

Thanks Y'all

circleD · October 11, 2015, 08:40 PM

Honestly, if you research what size you need it would be for a truck and not a RV. But most coolers have a rating on the package for your needs. If you have a 12,000 pound camper then get a 15,000 pound rated cooler. It goes by the GVWR I believe but I would put the biggest one in there that would fit. The more fluid you have in the system the better. It gets cooler before returning to tranny. Mine has 2 big coolers hooked together.

Froggy1936 · October 11, 2015, 11:24 PM

This is true to a point, There is a minimum operating temp for an automatic transmission (150o) You do not want to overcool to the point of too cold ! There is a chart on here somewhere of all the temperatures for an automatic Frank

stopngo · October 11, 2015, 11:50 PM

Thanks both of you. I did not mention that there are trans fluid lines hooked up to the Radiator by factory but I am assuming from what I have been reading and hearing that this is not sufficient for the weight carried. Is that correct??

Thanks

circleD · October 12, 2015, 09:30 AM

Those are for a truck not an RV. The chassis is built usually for a 1 ton service van and the drivetrain is for a pickup or service van. They put the RV body on it and say it'll hold up to the weight. Splice into those lines to add your cooler. You can still utilize the stock one but make sure it doesn't leak. Always have a way to bypass a leaking hose to at least get you somewhere safe. When I say safe I mean off a major road and park in a good position for the tow truck to hook up to you.

Rickf1985 · October 12, 2015, 09:40 AM

It all depends on which cooler you have. I have the optional cooler on mine which came with a plate type cooler in front of the radiator from the factory, plus the lines go into the radiator after that cooler. I also have a huge combination oil cooler/ac condenser in front of the radiator. also stock. Keep in mind that whatever cooler you put in front of the radiator will just add heat to the cooling air that is going through the radiator. That in turn can cause an engine overheating issue if you add too many coolers in front of the radiator, plus they do block some airflow.

ClydesdaleKevin · October 12, 2015, 08:37 PM

Totally not sure how accurate my transmission temp gauge is. But after years of running it with my modified dual cooler system and my dash switch to control the fans, we've had no problems. Years and lots of heavy miles. Typically with the fans off and moderate outside temps and rolling hills or flat roads, the temp gauge reads around 110 or so, although there have been days of traveling on the flats on New Mexico in the winter where the temps stayed around 95 degrees. Hot days, more like 150 to 160. Huge hills without the fans, it will just keep going up to just over 200. And then the fans get turned on, which usually brings it all back to 150 or so. Our steepest climb of the year is Phoenix to Flagstaff. April, so its started to get warm in Arizona...and our highest temps on that climb are still around 200-210, fans full on.

Kev

Rickf1985 · October 12, 2015, 09:10 PM

Those temps are really too cold. You can get condensation that will not evaporate out. That will lead to acids being formed from water and oil mixing. Same scenario as an engine running no thermostat. How many of you old timers remember the milky goo that used to form under the oil fill cap?

M & J · October 12, 2015, 09:19 PM

I remember Rick.

stopngo · October 12, 2015, 10:48 PM

Thanks again Y'all

QuoteKeep in mind that whatever cooler you put in front of the radiator will just add heat to the cooling air that is going through the radiator

I have thought about that. Would it be too revolutionary to simply run long lengths of copper tubing with cooling fins such as on a Hot water heating system along the frame rails? The fact that it isn't in the main airflow in front of rad might be compensated for by extra length and surface area. Am I making any sense?

QuoteAlways have a way to bypass a leaking hose to at least get you somewhere safe. When I say safe I mean off a major road and park in a good position for the tow truck to hook up to you.

Thanks for that advice

Rickf1985 · October 13, 2015, 07:02 AM

Quote from: stopngo on October 12, 2015, 10:48 PM
Thanks again Y'all

I have thought about that. Would it be too revolutionary to simply run long lengths of copper tubing with cooling fins such as on a Hot water heating system along the frame rails? The fact that it isn't in the main airflow in front of rad might be compensated for by extra length and surface area. Am I making any sense?

Thanks for that advice

It makes sense but the problem would be vibration. after a while there would be area where the vibration would work harden the copper and it would crack leaving you with a leak. What you are proposing is basically a cooler in a different form, you could mount a cooler down there but you have the exhaust down there too.

stopngo · October 13, 2015, 12:14 PM

Quote from: Rickf1985 on October 13, 2015, 07:02 AM
It makes sense but the problem would be vibration. after a while there would be area where the vibration would work harden the copper and it would crack leaving you with a leak. What you are proposing is basically a cooler in a different form, you could mount a cooler down there but you have the exhaust down there too.

Ahhha........Good point.

Thanks

ClydesdaleKevin · October 13, 2015, 07:31 PM

No problems with condensation, and the fluid always looks clean and red with no funny smells. Again...not sure how accurate my gauge is, but we always run heavy. Its about time to chance the tranny fluid again (every 2 years), so I'll let you know what it looks like when I do. Filter and fluid is every 6 years. Fluid every two (my pan has a drain plug).

Kev

HamRad Mobile · October 22, 2015, 09:03 PM

"Over-cooling the Engine Oil or the ATF."

I think we can work with that.

There are two companies I can suggest right now who have thermostatically operated fluid controllers to bypass the external fluid cooler, or to allow the warmer fluid to go to the cooler for temperature reduction, just like with the thermostat for the ethylene glycol mixture inside the engine cooling system.

The Hayden Automotive 163 with 3/8 Female NPT ports.

The Derale Performance 25011 and 13011 with 3/8 Female NPT ports.
The Derale Performance 25719 and 15719 with 1/2 Female NPT ports.

These devices look like they were made by the same maker, and they are rated to open at 180 degrees F. to allow the fluid to go to the cooler, and they close the cooler port and re-open the bypass port when the temperature drops below 160 degrees F.

I have the Derale 15719 with the larger 1/2 inch female NPT ports in the ATF lines going out to the external, 8 inch by 23 inch, 13 pass, stacked plate and fin, 34,000 BTU rated, ATF cooler on the Winnebago Elandan for the 3L80 automatic transmission. I believe the transmission ATF cooler is rated to be used with vehicles around 20,000 pounds GVWR, so the 16,000 pound GVWR Winnebago Elandan WCP31RT should be happy with it.

I do not yet have all the temperature sensors installed in all the locations desired for monitoring the ATF temperatures, so I have no data yet on what the system is doing for the transmission fluid temperatures.

I can say that there has been a change in what I am seeing with the engine cooling system temperature. Previously before all the work, often I would see 220-230 degrees F. on the engine cooling system temperature gauge. Now the highest I have seen was just over 200 degrees F. while I was climbing up to Snoqualmie Pass. On the flat it seems to be running at about 190 degrees F. most of the time in a 65 degree F. ambient temperature. Well, then there is the point that those higher temperatures were seen while the front of the radiator core, hidden behind the air conditioner condenser, had a lot of straw, wheat chaff, seeds, small leaves, and similar stuff, on the radiator core. Now that poor thing can breathe again. And the ATF cooling coil inside the cool side of the radiator has been blocked off, so no ATF adds heat to the engine cooling system.

Enjoy;

Ralph
Latte Land, Washington

lngfish · October 30, 2015, 07:53 AM

HamRad,

That sounds nice what you have. My 87 Holiday Rambler 30 footer has about a 8" x 8" stacked plate cooler. None of the ATF oil goes to the radiator.

About the only thing I have done as far as air flow goes, is I removed the what were factory installed fans in front of radiator. I removed them because I felt they were not needed plus they were frozen up and rusty. This improved air flow allot.

I wonder if what I have is sufficient ball parking it I mean.

I do like the idea of what you having being automatic with massive BTU's.

Have to put on my wish-list.