Added second cooler to silvy today..It was an all day affair I made custom supports, and lowered the stock cooler. I lowered the stock cooler as it was dead center with the chevy emblem on the grill. Blocking it completelyOverall Im happy with the install with what I had material wise..I took it for a spin and trans temps where in the 140's out on the highway.When I get the camper in a few weeks Ill post back towing temps...I found a GM 90 push lock to come out of the stock cooler to get to the new cooler. That made no hose bends there. A nice slope on the top hose with a clamp to the support.I used nylon spacers to bring both coolers out some to front of truck.Together its about 40k GVW. The new one is a 30K hyden and stock GM is whatever..The thing with the stock GM plate fin cooler is if fed from bottom I dont think they get 100% cooling as the fluid goes in and comes right out I assume. ( Dont fill all the way?)So I fed the out from stock into the bottom of new to insure full fluid fill into the new cooler from bottom up...

EXCELLENT JOB !!!!!And able to keep the OEM routing back into the main coolant radiator...that keeps the ATF heated in extreme cold areasAlso, good job of documenting this nice mod

Nice install. 140 was about what we ran after i put an aftermarket Hayden trans cooler on our 2007 Tahoe - towing out toy hauler fully loaded about 6k we ran at about 190 on hills and about 180s on the flat IIRC.

Nice looking install. I'm not a big fan of adding additional trans coolers in general especially when the factory already has both the OTA and OTO coolers installed. These cooling systems have a lot of design in them and include a critical factor that adding an additional cooler to what is already there can have a potential negative impact. That factor is "flow rate". A specific cooling system has a flow rate window where if you happen to reduce that flow outside that window you can negatively impact the overall cooling capacity and effectiveness. IMO the most critical part of a good heavy duty trans cooling system is making sure that the OTO cooler is working at it's most effective point since that is often where cooling issues are the most critical and the OTA coolers do little to augment that part of the cooling equation.Another thing many don't realize is that trannys are designed to operate at temps in the 170 deg or so range and getting them up in temp closer to 200 deg is actually beneficial since it helps keep any moisture in the ATF down thru evaporation. Thus adding too much OTA cooling can actually negate this benefit during cold weather and light load and higher speed operations where the tranny never sees much above 150 which is really not something you should want to see as a routine max temp.Larry

This is a good install. The number 1 enemy of transmissions during towing is heat and the coolers go a long way to preserving the transmission. Something some people add is a thermostat that will bypass the aux cooler until until it's needed. For me, my new to me 2008 F150 came with out the factory tow package. It has a standard Radiator and a standard transmission cooler. The radiator is about 1 inch thick and the HD radiator is about 1 1/4 thick but has more cooling fins per square inch. The transmission cooler is a four row cooler vs the HD cooler which is a 9 row unit. I'm resolved to installing the bigger radiator when it's time for some heavier towing again but I'm not sure if I will install the factory 9 row transmission cooler or go with a two cooler system like you have. Thanks for sharing your clean install, it makes me think more about what I want to do. Thanks!Jeremiah

One thing I remember from automatic transmission class is overcooling can be just as dangerous as overheating the fluid in certain situations and one should always run a OTA cooler before the OTO so the radiator can warm the fluid back up. While not practical our instructors shop truck had three temp gauges to show how much of a difference there can be in oil temperatures Pan sensor, fluid Out and fluid In sensors. Modern light duty trucks (yes, your ram 3500 is light duty) use thermostats to bypass the oil to air coolers until a certain fluid temperature has been met. One does not want to be towing in overdrive, 45 degree outside temperature and be cooling their trans below engine coolant temperature.

Added second trans cooler silverado 5.3. | Good Sam Community

ktosv
Explorer
Apr 27, 2017
FunTwoDrv wrote:
Good stuff here... so what are you guys using to measure the GM trans temps? Our 2014 Express 4500 has the 6.0/six speed GM trans and no temp gauge.

If you have a smart phone, pay the $5 for the Torque Pro app and pick up a Bluetooth dongle to plug into your OBD connector. Then, with a little of in app setup you can monitor probably hundreds of parameters.

My favorite three were tranny temp, engine oil temp and % ethanol in the gas.
BenK
Explorer
Apr 27, 2017
Kinda sorta...but...

Even old, old, old ATF had specifications for it's manufacture and usage...meaning a temp range it operates at best...again refer to the human temp range example in my post at the beginning of this thread...and note that the humans a decades ago likewise used the same heat rejection management system as modern man does...

The key to ATF temp management is that it is normally plumbed to go into and out of the main radiator's cold tank

That cooling system does have a thermostat and a temp range it manages the coolant to. The coolant has many input sources of heat...ATF is one of them and the ATF/coolant temp is managed by the main radiator's thermostat

Why plumbing the AFT external radiator BEFORE going into the main radiator is important. In extreme cold, it will over cool the ATF below it's operating range and by going into the main radiator...it will be re-heated by the main radiator's coolant in the cold tank

In extreme conditions where the ATF gets too hot...the external radiator will cool it and going into the main radiator's cold tank...it will either cool the main radiators's coolant if it is cooler. Guess it can heat it too, but can't see how the various controls would allow that...unless the AFT gets so hot...the external ATF radiator can NOT cool it enough...so it goes into the main radiator hotter than the coolant in there

Congrat's on the second career...and in teaching too boot!!!!

PS...fav town when traveling a lot was Chapel Hill (bought a few small companies for my company, Sun Micro and had to check on them monthly) and LOVED going to the surrounding eateries of Duke U...am 6 foot and felt tiny compared to those kids out and about there...

Thanks for the reminder and me going down memory lane...had forgotten that part of the country

falconbrother wrote:
My second career is at a community college. I asked one of the automotive instructors about adding the extra cooler to supplement the GM extra cooler. He said it wouldn't hurt a thing. Mine is a 2000 model. The older vehicles do not have the transmission oil thermostats like the newer vehicles. So, he said that for my 2000 it wouldn't hurt at all. The older vehicles do not need the transmission fluid to be at a certain temperature range like the new vehicles. In a new(er) truck it might be an issue because they are designed to run within a temperature range. He said that when towing it's going to get warm/hot anyway and in winter it will still warm up. But, it doesn't have real specific temperatures that it needs to operate like the late models. So, I'm adding the extra cooler to the Suburban.
falconbrother
Explorer II
Apr 27, 2017
My second career is at a community college. I asked one of the automotive instructors about adding the extra cooler to supplement the GM extra cooler. He said it wouldn't hurt a thing. Mine is a 2000 model. The older vehicles do not have the transmission oil thermostats like the newer vehicles. So, he said that for my 2000 it wouldn't hurt at all. The older vehicles do not need the transmission fluid to be at a certain temperature range like the new vehicles. In a new(er) truck it might be an issue because they are designed to run within a temperature range. He said that when towing it's going to get warm/hot anyway and in winter it will still warm up. But, it doesn't have real specific temperatures that it needs to operate like the late models. So, I'm adding the extra cooler to the Suburban.
falconbrother
Explorer II
Apr 23, 2017
falconbrother wrote:
falconbrother wrote:
Following..

I started to do this exact thing and decided to take a wait and see attitude before I started. I have the cooler but, haven't yet decided to do it. I custom made a drain plug for my transmission pan so that I can do regular drain and fills to keep the Dex6 healthy. That stock plug sucked on the 4L60e.

I realized that I had a misspelling and tried to correct it and this is the result.. Whatev's..
falconbrother
Explorer II
Apr 23, 2017
falconbrother wrote:
Following..

I started to do this exact thing and decided to take a wait and see attitude before I started. I have the cooler but, haven't yet decided to do it. I custom made a drain plug for my transmission pan so that I can do regular drain and fills to keep the Dex6 healthy. That stock plug sucked on the 4L60e.
FunTwoDrv
Explorer
Apr 23, 2017
Lawrosa, we do have the DIC but, it does not include trans temp. I guess that was an option Coachmen didn't select. LOL. If the sensor is in the trans, maybe I can find something that will read it properly. Or, maybe it is something the Chevy dealer can add to the DIC via their computer... I'll call.

Thanks,
Gary
lawrosa
Explorer
Apr 23, 2017
FunTwoDrv wrote:
Good stuff here... so what are you guys using to measure the GM trans temps? Our 2014 Express 4500 has the 6.0/six speed GM trans and no temp gauge.

Gary

Hmm 2014. Dont you have the DIC? It should be in the menus somewhere..

Sometimes I read when in tow/haul mode it automatically pops up..

Im not familiar with the 4500 express van dash..
lawrosa
Explorer
Apr 23, 2017
FunTwoDrv wrote:
Good stuff here... so what are you guys using to measure the GM trans temps? Our 2014 Express 4500 has the 6.0/six speed GM trans and no temp gauge.

Gary

I sent my cluster out to a local place in Connecticut I believe. They put in the factory temp gauge and changed all the bulbs to long life. They also replaced all the stepper motors. I got a good deal at the time of less then $200..

It was plug and play as the sensor is already in the tranny from GM..

You can get a cluster out of a 2500 but you have to mess with vin code transfer, milage, engine ours and such.

Hardest part was driving around two days with no cluster. Cant read speed or how much fuel etc etc..

Installed
FunTwoDrv
Explorer
Apr 23, 2017
Good stuff here... so what are you guys using to measure the GM trans temps? Our 2014 Express 4500 has the 6.0/six speed GM trans and no temp gauge.

Gary
ulvik
Explorer
Apr 23, 2017
I installed the same type of system in my 2010 but I just spliced the tranny line out of the radiator and just tied the second cooler into there. With both coolers towing over 8,000 miles through out the US I have never had the temp climb above 170 degrees. And that was towing up very steep mountains in the Rockys. Most of the time it stays from 120 to 135.