Hey guys,

Hoping all of you that have installed trans coolers can help.

A friend of mine has a '98 F-150 SCAB w/4.6 and he is loaning his truck to a friend of his (I know, I know, but he's a nice guy, and this friend is replacing both exhaust manifolds in return) to tow his rather large (approx. 5000 lb) camper trailer for a camping trip. He bought a Tranny fluid cooler at AutoZone and a kit to install it and got out the door for around $50.

Now he is asking me what I think about him installing the cooler kit. His question is whether this cooler is going to help enough to make it worth the time and energy he is going to put into it. I told him I didn't know a whole lot about the coolers that don't have fans on them but I would check with you guys who have them. I wouldn't mind doing the same to my truck as well.

Ok, here's the questions. Will he gain enough cooling capacity by adding this 6 core cooler to make it worth the money and time he's going to put into the project? If so, do any of you have suggestions on how to mount the thing. The kit include--get this--tywraps (wire ties) to attach the cooler to the truck. Also would you recommend a certain brand of trans fluid temp gage and how much can he expect to pay for a gage? Thanks in advance for your expertise. --DIY

 

What cooler did he get it it a tube and fin or a plate style? The plate styles have a place to mount them better. Keep at least 1 inch between the radiator and the cooler. Don't run long lengths of hose use steel line with short pieces of rubber to connect them and don't forget to bubble flare the ends of the steel.
Alan

 

The cooler he got is a tube and fin style cooler. Thanks for the advice. Anyone else?--DIY

 

If the truck never had a cooler then you are doing the owner a favor by installing one.
5000 lbs is a good amount to tow but depends on the terrain, how far and the average temp.
Installing a temp gauge is not going to help with the project except again doing a favor since the owner seems not to tow or does only light towing at times.
I would consider at least a 24,000 GVW cooler rating and a 10 " fan on a thermostat. Mount the senseing bulb on the trans cooler line 'from' the trans at the radiator. Set the thermostat at about 180° so it will come on at that fluid temp as well as the underhood temp. The fan does more than cool the aux cooler in this installation. Cools at low road speeds when needed the most. Helps with air conditioning and vents the engine bay after shut down if the temp is high enough. Power direct from the battery thru a fuse.
Do not mount the cooler fast to the radiator. Make brackets and mount to the radiator apron in front of the A/C- Radiator because there is posibility of rubbing a hole in the radiator from vibration.
Hayden has both fan and fully adjustable thermostat at about $85, found at Advance Auto Parts.
I use this setup with a custom built trans pulling 12,000 gross weight and the temp never goes above 230 ° measured at the output cooler line of the trans before it gets to the radiator and aux cooler.
However I would not gaurrentee the same temp performance for any other turck because my trans is a special build and runs at reduced temps to begin with.
I know this is more than you wanted to hear but another real application never hurts to hear about..

 

I have never been one to suggest a fan for many applications because when you are moving the air will pass through the system anyway and the radiator has a fan to pull the air through it anyway. I really dislike the tube and fin coolers because they aren't very effective. The fluid passes through them quickly not giving very much time to actually cool it. I generally suggest buying the hayden 679 part number which is a plate style cooler. It has a bracket on the top of it that makes for easy mounting. Personally if I were seeing trans temps of 230 I would be getting a long tru-cool 44,000 gvw unit. I like to keep these transmissions really cool because they last better that way. Ideal temp for me is about 160. The only problem with over cooling is if the trans runs below 100 the pcm will not think the trans is warm so overdrive and lockup will not operate.
Alan

 

You will never run 160 out of the converter while towing any high amount of gross weight.
I know you build transmissions but there is no way to keep the fluid that cool under unlocked shearing and high loads while towing.
Lets be sure what locations we are talking temp.
The pan can surely operate in the 160 areas but the output of the converter will never run at pan temp under towing conditions with any size aux cooler installed with or witout a fan.
The fluid from the return line does not just dump back into the pan. It is routed to other areas for lubrication and cooling so picks up heat again before finding it's way back to the pan.
What about thoses trucks that use electric fans that don't run all the time?
Your position on fans is not very strong in that light.
Under low road speeds the air flow is also low. Whats wrong with additional air flow same as any fan behind the radiators.
Last I knew A/C dosn't work as well sitting still as when moving.
Been thru all this is why I am taking this strong position.
As far as temp of fluid goes, don't ignor the capability of the fluid.
The fluid has to be at at least a reasonable temp to do it's lubricarting function and still be cool enough to not to breakdown from exceeding it max operating temp. The max operating temps are far in excess of 200°.
The bands and clutches wear the most at the moment of high friction in the beginning of lock-up and again just at the point of release from there mating metal surfaces.
While towing steady no shift, the most heat is produced from converter fluid shear. If the fluid is kept under 250° the cooling requirements have been met in most cases because this is well under the breakdown point of the fluid.
The clutch and band material that becomes suspended in the fluid does more damage than the fluid temp and begins to load the clutch pores permoteing slippage and increased heat on just that inherent action.
These actions cannot be escaped no mater what is done because it is an inherent action.
One can only change fluid often and keep the shifting as tight a reasonable to reduce these degrading actions for prolonging overall trans life. Sooner or later the trans will suffer failure from these normal actions.
I know you understand all this.

Again , I have a custom built trans and able to see how much heat can be reduced with optium build for that end as compaired to a stock trans that is good but only just adiquite for general public use not towing max loads on a continious basis.

 

It sounds to me like you need to have a custom built converter of a very low stall since you are not locking it. Or a converter you can lock under the load however I'm not sure the transmission will handle the blow if you do that. The splines inside these transmissions are prone to breakage. Not using overdrive helps alot but you still have a significant amount of load on the forward hub. Regardless I think you need more cooler.
Alan

 

If your replying to me, yes, the converter is a Diesel low stall dual clutch.
The flud pump is high volume, the clutches are Red Raybesto with their matching plates, valve body mods, all hi load torringtons, bearings and bushing, special EPC valve, alum deep pan and other parts.
The trans now uses Mercon III fluid as needed by the Raybesto clutches and band.
Being that I lost the original build from a ballooned converter not a heat problem, I had it built by Level 10 and if anyone can see the difference I can, towing nearly 12,000 gross with a 4.6L. This 281 engine can make more torque than most think.
Under the towing conditions I would not rebuild stock and have the same thing happen again.
Level 10 is one of the best shops in the country for custom builds being in biz 35 years, so I went to them without question because I knew of them when they first started in biz (i was young at the time) and got a product they said would work well and it sure does.
This rig impresses a lot of people who ride with me going to the race track.
I guess we beat this about enough.
Just bringing info to the masses that there are other ways and means of doing things beside the same old things that keep being said.
It's called advancement in the state of the art. Benifit from it.

 

I am not a fan of the red clutches or any of the raybestos for that matter. I like the dynax frictions that ford used and I also use those materials for torque converter clutch and overdrive band. If you have a dual friction unit you trust then why are you not engaging lockup?
As for the fan on the cooler unless it is in a location that does not get airflow I don't see the point. Did you upgrade the cooler lines to 3/8 line throughout or are you still operating the system on the stock 5/16 lines? The most effective cooling for me has always been a 44,000 gvw "long" tru-cool cooler with 3/8 lines running all the way to the transmission. Mount the cooler as far forward of the radiator as possible and delete the automatic transmission fluid section of the existing radiator. If you run in severely cold weather you will want that radiator for warming of the fluid.
Alan

 

My lines are 3/8 from the factory. Matter of fact you may take exception to it but the radiator line fittings had to be removed from the OEM radiator for reuse because no others were to be found without special order from a dealer at $35 each.
The OEM 3/8 metal lines are reused with 3/8 rubber line sectioned in to include the aux cooler.
The cooler is located well ahead of the A/C condener favoring the passenger side on metal brackets and rubber shocks.
Level 10 will not warrenty without the cooling section thru the radiator.
It is fine that you don't care for raybesto. I am not at all saying your choice is poor because I am not in a position to make that judgement.
In my opinion your setup is border line over cool but if it works for you that's all that counts.
Fluid that is too cool does not lube well in the trans in the early startup stages and running under load and does not need to be aggravated with over cooling, without the radiator in line and such.
I do fully understand cold weather effects. The line pressure goes quite a bit higher before the fluid thins, shifting becomes harder and delayed as well as OD will not engage until much later in the warm-up cycle when the TFT is satisified and permits it.
The bigger is better is not always the way to go for every case no more than you would use an over size carb on a small engine or to much cam duration or any situation that the tech science of it is ignored by the ignorant who subscribe to the bigger is better theroy, then wonder why it doesn't work as they expect.
As far as lock up goes, it works the same as OEM.
There are other ways of seperate lock up control but you have to consider the engine size is borderline small so you cannot lock up to much at low rpms and still have any torque left to pull with. Same idea as using a higher stall converter for speed performance.
My drop in operating temps came about from less converter slip, faster shifting, hi fluid flow, good cooler, larger radiator and the oversized pan however much it's worth.

 

I don't understand your drop in temperature you are saying 230 and to me that is too hot. I like to run the transmissions closer to 180, I'm even ok with 160. Anything over 100 is acceptable to the pcm that the point at which the computer will not allow 4th gear or lockup. I understand fully about low rpms I would think you would have a low gear for towing a heavy load. The setup I refer to is definately not for everyone. Most applications I suggest a hayden 679 unit installed with the radiator. Usually the applications I deal with are taking seriously high stall converters. I 4000 stall converter can make your transmission go from 100 degrees to 200 in just a few seconds waiting at the line even with that massive cooler and 3/8 flow. I wasn't aware the trucks with 4r70's came with 3/8 lines I have only noticed it on explorers at this point,but I haven't worked on any newer than 02 trucks recently.
Alan

 

I don't know where your misunderstanding on the temperatire issue.
I am referring to the output line of the transmission to radiator as the "output from the converter". This is where I measure my temperatures ( about 6" from the trans output fitting) and feel it is the most important place to know that information from.
No transmission under unlocked conditions such as starting out from a dead stop, running up thru the gears, running in stop and go traffic will keep it's fluid anywhere near 160° +, - or any other condition after fully warmed and pulling a load for very long. You cannot defeat the physics of fluid shearing no matter how much cooling you have by aux means.
Again I am not referring to Pan temps that are always lower than the converter output so is of little consequence to me.
Matter of fact if you test your setup, I'm sure you will find that at the output temp of you aux cooler will be below your Pan temp.
If that is the case, IMO you are for all intent over cooled and doing no better with that large a cooler.
I mention these things because I have already investigated them in the past with Infrared heat gun measurements. "Absolute" temp accuracy is not needed because all areas are measured with the same insturment and a black surface by intent so reflectivaty differences will not result in large unaccounted for differeces and become miss leading.

 

I have tested this setup. I had a car that had 3 temperature gauges on it here. With a 4000 stall converter under normal driving conditions we were seeing a 140 return line temp, 190 feed line and about 160 in the pan. I was very confortable with the setup. That was operating with outside air at about 60degrees. The guy lives in the south so we left it like that. On a northern car I would have run back through the radiator to warm the fluid to the 180 of the coolant. After a year and about 35k miles the fluid stays bright red and the transmission still works great. I custom built the transmission with the following components.
late design 4 plate dynax (grooved) intermediate
7 plate forward using oem red frictions (no other choices except blue's or "gag" alto's)
3 plate reverse with 2 groove servo (this helps reduce drag for racing)
8 plate direct using late dynax frictions
I also used a black high carbon overdrive band
The converter is a billet unit that I supply that has no damper springs to break and a billet lockup piston.
By no means would this be a setup for a truck but it will definately test the cooling ability. This car weighed around 4000 lbs (markVIII) and ran mid 13's in the 1/4. Like I said the setup I used on that isn't for everyone.
Alan

 

Good talking with you Allen.
Keep up the good work.