I am adding an auxiliary trans fluid cooler to my C-6 in my F-250.
Should the fluid route thru the aux cooler first then the stock rad cooler, or thru radiator cooler to aux cooler?

WHich stock hard line is fluid FROM the C-6 (HOT), and which is the return line (cold)?

THANKS!

Vehicle is 78 F-250 4x4 crewcab, 400/C-6

 

The messy way to figure it out is to pull the lines, use a couple of bottles to catch the fluid and have someone hit the starter. Don't start--just a turn or two will prove up the pressure side.

I am of a mind to run through the aux first, then back through the stocker.

Reason being, if you have cold weather, the fluid going through the stocker will ensure it is not too cold going back to the trans.

This came up before here, and some folks in hot areas think aux only. Hot or not, I'd go back through the stocker no matter what.

Good luck.

 

ATTN C-6 Gurus-

Does anyone know which port/outlet on the RH side of the case is outflow and which is in?

Any opinions on the cooler? Would very much appreciate the help...

 

IMHO, plumb in the oil cooler and don't run it thru the stock rad cooler. In hot weather the hot tranny fluid heats the water in your cooling system, which is having a hard enough time cooling the engine. The oil cooler will be enough to keep the tranny cool. I'm not sure if the tranny fluid needs heating when the weather is cold though, maybe an expert can help with this.
Sorry I don't know which line is which. ...Terry

 

Thanks for the info- I hadn't thought about the heat transfer TO the radiator from the tranny....

 

Gentlemen, Radiators are there to carry the heat generated by the drive train out. Newer vehicles do a better job of funneling air through the radiators to maximize air flow, than the old models. My 66 F100 has a very large rad. and had a flat 4 blade fan. On my 97 Taurus you can't even see the rad. but it will idle a couple of hours in 97º heat with the a/c blowing and the temp guage never moves.

Any extra cooling for the tranny is good. The line going to the rear of the tranny is the return line and should have the fluid come from the rad. through the extra tank and back.

Sorry but I disagree with bypassing the rad.

John

 

OK, so ATF flows out the front port (closest to the bellhousing) to the cooler, then back thru the rear port...
I would like as much cooling as possible, so will try the stepped cooling using the radiator one first, then the aux air to fluid cooler...
Thoughts?

 

That's the way Ford does it.

John

 

I always go to the stock cooler first because it is possible for the trans. fluid to pick up heat from the radiator cooler. This is why many transmissions die shortly after an engine overheats. I have seen that happen on many trucks including Fords and Dodges.

As for which lines, if you can not tell by looking at it, just touch one of the lines (avoiding the cat. converter), one will be way hotter then the other after a short period of driving. I suggest not touching it at the front of the vehicle since the fan can nick your fingers or blow stuff into your eyes. I do it from the side.

 

Anyone know what normal opperating temp for auto-trans oil should be? OR max temp? I'm thinking way higher than the 190/210 that the engine coolant should be running at.
If so, I would think that oil or trans fluid should go thru aux cooler first, then radiator.
First, on cool/cold starts the fluid would have the bennifit of warm up, and all fluids are designed to perform best at normal operating temps.
Second, if they do infact run hotter than the rad temp, then the aux cooler will lower the temp befor puttihg extra burden on engin cooling system.
Even an over heated engine at 250 or so, should be well within the opperating temp of trans fluid.
Just MHO (2.2cw)

 

Installed my cooler AFTER the stock rad cooler per instructions in the box. Only makes sense as you'd just be heating it back up the other way 'round. After it went on I noticed a good 10deg drop in engine temp while crusing unloaded. While towing it stays MUCH cooler.

My '83 did require an extra set of adapter fittings to mate the cooler with the stock trans hardline and radiator fittings, and I bet your '78 will too. The fittings are a standard diameter, but about twice as long as normal. These are not included in the cooler kits, but found them at the local auto parts store for about $7.00.

 

I went through my radiator cooler first then to my cooler's.

 

IF the "engine is running cooler", then the trans fluid must be absorbing the heat, therefor heating the trans oil. (Not "cooling")
If you want to change the temp of anything, you must pass it thru something that is cooler or warmer, in the direction you're trying to get to.
Most engine normal opperating temps (coolant) are from about 180 to 210 Deg. Far. and that is the temp of the radiator. (+/-) Run hot trans oil, or any fluid thru this enviroment, and itwill either leave heat or loose it.
I thought that the "normal" opperating temp of most fluids in even extreem conditions, was more than engine coolant temps of 210. That is NOT a very high temp.
Please ---Someone pipe in here, as I would like to know, and fill me in on the science of all of this.

 

The engine running cooler has to do with a lower thermal load on the whole system. With regular operating conditions [flat land/ no load] the trans and radiator temps will balance out at about the 180-190 deg range which the stock cooling system is designed to maintain. Average operating temp of the tranny will be warmer, so it is generally dumping its extra heat into the radiator coolant. Figure in the extra heat loss of a big tranny fluid cooler and that balance is going to shift down. How low depending on outside temp, your thermostat rating, and size of the cooler.

Just as your engine needs to "warm up" to run its best, the tranny needs to reach 150 deg for proper operation. On cold mornings ever notice your auto trans vehicle warms up faster when driven than simply idling in the driveway? Part of that is the tranny heat getting passed into the engine coolant. All else being equal, manual transmission vehicles will warm up slower and run cooler. The torque convertor is a big heat producer, and fluid exiting the convertor can be as much as 50 deg hotter than in the transmission pan.

The two cooling systems are tied together for a reason, they help balance each other out. Engine temp stays within a rather narrow safe operational range and fluctuates more slowly [larger thermal mass]; tranny temp covers a much wider operational range and can rise more rapidly [smaller thermal mass]. When you exit the flat land/ unloaded conditions, the tranny starts producing much more heat. Start up a long grade or tow/ haul a load and the trans temp can rapidly climb to 225 deg in the pan, which means you probably have 275 deg fluid exiting the convertor and going to the cooler[s].

This is why auxillary coolers are a must for towing, rock climbing, mud bogging, any situation where an AT is spun at high input RPM for a relatively low output RPM. The stock cooling system simply can't absorb and dissipate that much extra heat for any length of time. Compared to a manual tranny, the AT can let you live with many fewer gears when it comes to low speed/ high load conditions. The convertor does a fine job replacing a mechanical granny gear, it just generates a bunch of heat doing so, and that heat has to go somewhere.

 

I have a 93 F250 with a 460 and a e4od tranny in it. I plan on installing a trans cooler in it, and I'm wondering if I should get on with a built-in fan or just put one in front of the radiator. I plan on pulling a fifth wheel camper, about 11k. Any ideas would be appreciated.