• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

M1008 external trans cooler

mbavers

Member
73
18
8
Location
homer ak
Plow truck only. I am replacing my radiator and am contemplating placement and routing of my external transmission cooler. Most people seem to route the trans fluid through the engine radiator first, then to the ext. trans cooler, then back to transmission. I feared that, on very cold days, the trans fluid may get too cold to perform optimally, so I routed it to the ext. cooler first, then to the radiator ( to partially re-warm it), then back to trans. Yeah, I could hook up temp gauges and experiment under different conditions, but I'm an old guy and time and patience are limited. Operating temps for plowing are anywhere from below 0F to 35F. What would you do?
 

antennaclimber

Moderator
Moderator
Steel Soldiers Supporter
1,368
950
113
Location
State College, PA
From the Hayden Web page:

Should the cooler be installed before or after the radiator?


Answer:
We recommend installing the auxiliary cooler after the radiator to return the coolest fluid directly to the transmission. Installing the cooler before the radiator will still provide additional cooling and may be necessary in some difficult-to-access applications.



Can you over cool the transmission fluid?


Answer:



Some transmission problems really are unique to the cold weather while others get worse. Metal components contract as they get colder which results in component mates loosening up, parts wearing quicker due to friction from reduction in clearances between components, and can develop leaks from shrinkage and hardening of seals and gaskets.

The ideal operating temperature for a transmission is 180°F. The viscosity of transmission fluid changes and gets more viscous at lower temperatures. As the transmission fluid (ATF) falls below 32°F, its viscosity becomes significantly higher, restricting where it can flow to lubricate the internal components of a transmission, leading to premature wear. The use of synthetic ATF fluids is recommended where its viscosity at cold temperatures is lower than petroleum based ATF fluids.


It is critical in extreme cold conditions to use the original equipment cooler in series with an auxiliary or by-pass cooler and allow the vehicle to warm up before driving.


Hayden Transmission Oil Cooler FAQs
 

sneekyeye

Active member
253
135
43
Location
ALABAMA
Running it through the OE style radiator cooler second is fine. People will argue about anything, but your way is fine. It will likely not get overly warm anyhow in the cold weather through the main radiator, but in your cold temps, it could help.
 

mbavers

Member
73
18
8
Location
homer ak
From the Hayden Web page:

Should the cooler be installed before or after the radiator?


Answer:
We recommend installing the auxiliary cooler after the radiator to return the coolest fluid directly to the transmission. Installing the cooler before the radiator will still provide additional cooling and may be necessary in some difficult-to-access applications.



Can you over cool the transmission fluid?


Answer:



Some transmission problems really are unique to the cold weather while others get worse. Metal components contract as they get colder which results in component mates loosening up, parts wearing quicker due to friction from reduction in clearances between components, and can develop leaks from shrinkage and hardening of seals and gaskets.

The ideal operating temperature for a transmission is 180°F. The viscosity of transmission fluid changes and gets more viscous at lower temperatures. As the transmission fluid (ATF) falls below 32°F, its viscosity becomes significantly higher, restricting where it can flow to lubricate the internal components of a transmission, leading to premature wear. The use of synthetic ATF fluids is recommended where its viscosity at cold temperatures is lower than petroleum based ATF fluids.


It is critical in extreme cold conditions to use the original equipment cooler in series with an auxiliary or by-pass cooler and allow the vehicle to warm up before driving.


Hayden Transmission Oil Cooler FAQs
Thank you. I did not get an email notification of your reply, so my response is late.
 

87cr250r

Well-known member
1,267
1,988
113
Location
Rodeo, Ca
I would run it through the trans cooler first then radiator. The driver's side tank is a constant 180 degrees F as that is when the thermostat opens. There is no flow through that tank during warmup so the trans cooler will not delay the warmup of the engine. If the trans cooler is cooling the fluid below 180, then that will be extra capacity for the engine as it gets heated back to 180 in the radiator.
 

mbavers

Member
73
18
8
Location
homer ak
I would run it through the trans cooler first then radiator. The driver's side tank is a constant 180 degrees F as that is when the thermostat opens. There is no flow through that tank during warmup so the trans cooler will not delay the warmup of the engine. If the trans cooler is cooling the fluid below 180, then that will be extra capacity for the engine as it gets heated back to 180 in the radiator.
Thanks!
 

Curtisje

Well-known member
Steel Soldiers Supporter
596
693
93
Location
Okinawa, Japan
I agree with 87cr250r. Run your fluid from the tranny to the external transmission cooler and then through the radiator.

I've read several external cooler manufacturers instructions and they all seem to recommend the opposite. Here is my rationale:

I have 2 trucks that tend to overheat the engine during heavy towing, my 2001 Silverado and my CUCV M1028 Wrecker. The engine will only overheat once the transmission heats up past 220°. Until that point the radiator keeps the engine where it needs to be. So I install my external coolers before the transmission. This still allows the radiator to warm up cold transmission fluid just prior to it entering the transmission during normal operation.

I operate my trucks in the desert with summer temps near 115° occasionally so my environment is different from yours. You may need to take steps to prevent over cooling in the winter, I just don't know.

I wouldn't install an external cooler if I wasn't experiencing overheating. If it ain't broke, don't fix it.

Good luck.
 

WWRD99

Well-known member
Steel Soldiers Supporter
1,117
1,715
113
Location
York Pa
There are several Hayden trans coolers that have a built in thermostat that if the fluid is not up to temp it bypasses the cooler and sends it back. Chances are since you are plowing in one of the coldest places on the planet you'll never need it and would go in constant bypass. You have a probability of over cooling the fluid then trying to warm it up again in the coolant, so you may never get the fluid up to temp by going to the cooler first then the radiator.
 
Top