Okay you don't need one or want one. That's cool. Just PLEASE quit arguing the point. I FEEL along with some others that I needed one. What could it hurt you know? Maybe my tranny will last another 100k because I kept the temps lower. My warranty is out so I am willing to pay for the 6.0 cooler for extra insurance.

 

Even though it's been proven to you time and time again that there are circumstances where people have been able to put their rig in situations where the stock 7.3L trans cooler couldn't keep the transmission oil within factory heat range specs, you still continue to argue against people wanting to upgrade to a 6.0L trans cooler because they want a larger margin of safety.

Wow.



You should change your user name to Saint Jude.

Stewart

 

12k 5th wheel my 2000 with stock 7.3L cooler would BURY my autometer trans temp gauge, BURY as in OFF THE SCALE (250+)in stop and go traffic or going up logging roads when I could not go fast enough to lock the torque converter in 2LO.

I now have a 6.0l cooler and have never seen over 200.

 

That's not what I asked, it could be 500 degrees for all it matters. I asked how many miles did you get on the tranny with the stock cooler while pulling. Did your trans only last 5k miles, 10k, 100k? More?

 

I'm sorry, what's this thread titled again?

 

Good point.

The title is "6.0 Trans cooler Why?"

It ISN'T "6.0 Trans cooler Why not?"

But that doesn't preclude you from giving a dissenting opinion. I don't have a problem there.

My problem (and everyone else I would think) is you refuse to recognize there are conditions where a person can put their rig into a situation where the stock 7.3L cooler isn't adequate, and the 6.0L cooler would help.

It doesn't matter HOW many miles a person got with their stock cooler. What matters is there are situations and circumstances where the stock cooler isn't good enough, and the 6.0L cooler is.

That's all. That's what it boils down to.

Stewart

 

Maybe we'll get somewhere if I change gears. What is the proper running trans fluid temperature, what is it's highest allowable temperature before it becomes inadequate, before it fails and causes catastrophic failure to the tranny?

 

I don't have a clue on numbers, but I know what you're getting at. Is a transmission going to fail at 250*? No. 300*? Probably not. 350* using synthetic fluid? Maybe not. 500*? who wants to find out? But, and this is all we are saying, the longer a transmission operates at a temperature above the factory intended operating range, the more it's lifespan will be reduced.

 

I completely agree with that, Jeff, but how else do we determine predictable failure and thus the need for additional "upgrades" or protection rather if we don't know the fluids maximum operating temperature? Who said 250 is too high? Who said 300 is?

Someone has to know what it is.

 

Mark knows, and has already gone over this.

Pop

 

Several times over.

 

ConocoPhillips Hydroclear® V Automatic Transmission Fluid


Description: Conoco Hydroclear MERCON V Automatic Transmission Fluid is a premium multifunctional product that has been approved for use in all General Motors and Ford transmissions. It carries both the Ford MERCON® and MERCON® V trademarks, indicating that it passed the rigorous testing requirements set forth by the Ford Motor Company as outlined in these two distinct specifications. It also carries the General Motors DEXRON® III, as well as Allison C-4, approval and can be used in GM automotive, as well as heavy-duty, transmissions for on- and off highway applications. As a premium fluid, Hydroclear MERCON V Automatic Transmission Fluid meets and/or exceeds all the requirements set forth by Ford and General Motors.
Better Oxidation Control: Oxidation control is critical due to the higher operating temperatures of today's vehicles. Controlling oxidation increases the service life of the vehicle. Ford and GM use different tests to measure oxidation control, but a key measurement is the change in total acid number (TAN). Using it ensures that the vehicle will be protected and run at its optimum performance.

Better Wear Control: Having the right wear protection increases the durability of the transmission. Hydroclear MERCON V Automatic Transmission Fluid provides unbeatable wear protection for the transmission.

Better Low-Temperature Fluidity: This means improved cold-weather performance. One such measure of low-temperature fluidity is Brookfield Viscosity at -40°C. Hydroclear MERCON V Automatic Transmission Fluid has an 11,800 Brookfield Viscosity rating. The Ford MERCON V specification limit is 13,000 maximum, while General Motors specification is 20,000 maximum.

Friction Retention: A fluid needs to retain its friction performance so that the transmission shifts smoother. Using Hydroclear MERCON V Automatic Transmission Fluid means consistent shift-feel throughout the life of the fluid.

Information provided by ConocoPhillips.

 

MatWeb - The Online Materials Information Resource

Physical Properties Metric English Comments
API Gravity 30.8 ° 30.8 °
Brookfield Viscosity 11500 cP
@Temperature -40.0 °C 11500 cP
@Temperature -40.0 °F
Viscosity Measurement 194 194 Viscosity Index
Saybolt Viscosity at 100°F 202 SUS 202 SUS
Saybolt Viscosity at 210°F 54.0 SUS 54.0 SUS
Kinematic Viscosity at 40°C (104°F) 40.0 cSt 40.0 cSt
Kinematic Viscosity at 100°C (212°F) 8.40 cSt 8.40 cSt

Thermal Properties Metric English Comments
Pour Point -45.0 °C -49.0 °F
Flash Point 196 °C 385 °F

 

Per Mark K optimum temp for this trans is 170F. The fluid and the friction materials are designed and optimized there. Below is a chart with generic info regarding AT fluid and temps. Hardly scientific but it illustrates the point.

Now an anecdote. When I first got my truck, bone stock, I had occasion to overheat the trans a couple times towing the 5er. Flashing gear ****, brown and glittery fluid, the stock dash gauge saying all is well, the full experience. Grinding slowly up steep windy roads, the low road speed will not allow sufficient air across the stock cooler. I installed a real gauge and tried a "24k" tube and fin cooler from AZ in series with the stock. While better I could still see 230F which did not instil confidence. So I got serious, ditched the two coolers, and went with the 6.0 cooler. Same conditions, the temps stay in control, never over 200. If you tow heavy and slow you need a 6.0 cooler. If you don't the stock cooler is fine.

 

Good stuff David. Glad to have the info.