Coast Resorts Open Roads Forum: Tow Vehicles: Added second trans cooler silverado 5.3.

Print | Close

Topic: Added second trans cooler silverado 5.3.

Posted By: lawrosa on 04/21/17 08:29pm

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 completely

Overall 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...

[image]

* This post was last edited 04/21/17 09:30pm by lawrosa *

Mike L ... N.J.

2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh

Posted By: BenK on 04/21/17 09:24pm

EXCELLENT JOB !!!!!

And able to keep the OEM routing back into the main coolant radiator...that keeps the ATF heated in extreme cold areas

Also, good job of documenting this nice mod

-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...

Posted By: eDUBz on 04/21/17 09:39pm

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.

LBZ - Stealth TH - RZR 900 4 - Honda 450X - Paddleboarder - Fisherman - Kayaker

Posted By: LarryJM on 04/22/17 01:37am

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

2001 standard box 7.3L E-350 PSD Van with 4.10 rear and 2007 Holiday Rambler Aluma-Lite 8306S Been RV'ing since 1974.
RAINKAP INSTALL////ETERNABOND INSTALL

Posted By: jerem0621 on 04/22/17 05:57am

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

TV-2022 Silverado 2WD
TT - Zinger 270BH
WD Hitch- HaulMaster 1,000 lb Round Bar
Dual Friction bar sway control

It’s Kind of Fun to do the Impossible
~Walt Disney~

Posted By: 1320Fastback on 04/22/17 08:30am

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.

1992 D250 Cummins 5psd
2005 Forest River T26 Toy Hauler

Posted By: lawrosa on 04/22/17 09:01am

Im pretty technical savy and believe you cant overcool a transmission.

Its like giants vs jets...

Millions of transmissions running in the cold motor city area and artic regions .

Trans fluid flows @ -40 F AFAIK..

Posted By: Redwoodcamper on 04/22/17 09:53am

You can certainly have trans fluid too cool. Why would they route the lines next to the exhaust manifolds if they didn't want it up to temp? They make trans fluid to work up to 250+ degrees. It does degrade faster at those temps, but I would run it at 200 all day long. I've tore apart e40Ds, 5r110s and 48res. Clutch slip from soft shifts and not enough line pressure ruins more trannies than heat. Plus fluid these days is made very "slippery" for the softest shifts because people are whiners. There are some superior fluid concoctions out there over the oem.

2011 ram 3500. Cummins 68rfe. EFI live. 276k miles and climbing.
2017 keystone bullet 204

Posted By: Ozlander on 04/22/17 10:05am

By spacing the cooler away from the radiator like you did, the fan can't suck air thru it. No cooling when you stop at lights.
The factory engineers know what they are doing.
Put it back like it was.

Ozlander

06 Yukon XL
2001 Trail-Lite 7253

Posted By: dodge guy on 04/22/17 10:17am

Ozlander wrote:

By spacing the cooler away from the radiator like you did, the fan can't suck air thru it. No cooling when you stop at lights.
The factory engineers know what they are doing.
Put it back like it was.

But yet you put your hand in front of the grille with the good closed you can feel the air getting pulled through!

Wife Kim
Son Brandon 17yrs
Daughter Marissa 16yrs
Dog Bailey

12 Forest River Georgetown 350TS Hellwig sway bars, BlueOx TrueCenter stabilizer

13 Ford Explorer Roadmaster Stowmaster 5000, VIP Tow>
A bad day camping is
better than a good day at work!

Posted By: Turtle n Peeps on 04/22/17 10:19am

lawrosa wrote:

Interesting take on things.

Do you have any idea why OEM trans fluid is routed through the radiator which is around 180 to 210F most of the time?

Do you have any idea why the tranny won't go into converter lockup until the temp warms up?

~ Too many freaks & not enough circuses ~

"Life is not tried ~ it is merely survived ~ if you're standing
outside the fire"

"The best way to get a bad law repealed is to enforce it strictly."- Abraham Lincoln

Posted By: lawrosa on 04/22/17 10:40am

Ozlander wrote:

By spacing the cooler away from the radiator like you did, the fan can't suck air thru it. No cooling when you stop at lights.
The factory engineers know what they are doing.
Put it back like it was.

Putting a cooler against the rad or condenser reduces its cooling capacity because the radiator will not let the heat dissipate.

Ill find docs to support my claim..

My fans rarely come on at all..

The original gm cooler was a good 10" from the condenser. And it still is..

Posted By: lawrosa on 04/22/17 10:42am

Turtle n Peeps wrote:

lawrosa wrote:

Its still routed through the rad.. Yes to help warm up the fluid..

Will not lock up to help trans get warm.

Riding today with trans temps 120f convertor was locking up fine.

Posted By: Turtle n Peeps on 04/22/17 11:08am

lawrosa wrote:

Turtle n Peeps wrote:

lawrosa wrote:

Its still routed through the rad.. Yes to help warm up the fluid..

Will not lock up to help trans get warm.

Riding today with trans temps 120f convertor was locking up fine.

If you think you can't overcool ATF then why does OEM warm it up?

Posted By: time2roll on 04/22/17 11:38am

Do the hoses connect to barbed fittings?
I don't like rubber oil hoses with screw clamps but this does look like a good install.

2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up

Posted By: BenK on 04/22/17 01:15pm

It is all about the laws of physics and what folks 'see' is only a small portion of what is going on...that there are reams of specifications that are based on even more reams of scientific data, both calculated and empirical...then the management factors (idiots only concerned with managing their beans than the product)

Take a human body. It has a temp range (specification) for standing still, sleeping, running at curb weight (butt naked) or running with the max spec'd backpack & gear (includes shoes, clothing, etc)

The human body has a cooling system and a computer to control that cooling system

The computer controls the muscles which create the heat and the rejection stuff. Like increasing the blood vessel diameter close to the exterior covering (AKA skin) to reject it via convection & radiation. The other main cooling mechanism is sweating (phase change) in conjunction with moving more blood to the skin...they both work in concert

Too cold and the human body can function, but not up to 100% power

Too hot and the human body can function, but not up to 100% power

Any automotive vehicle is similar but not with flesh and bone, but with metal and plastic

ATF has three main duties.

Lubricate
Transfer heat
Hydraulic coupling (shear) in the TC

Heat is generated with pumping losses, friction and the biggie Hydraulic coupling in the TC

Then the endless opinions of whether the OEM stuff is good enough (it is...*IF*...the vehicle is used within the OEM specifications...of which few truly understand...and will toss in 'duty cycle rating' that even less understand)...whether a larger AUX cooler is a good/bad idea, whether to plumb that aux cooler before or after the main radiator, plumb a second external aux cooler in series or parallel, etc, etc, etc...

Posted By: lawrosa on 04/22/17 02:35pm

time2roll wrote:

Do the hoses connect to barbed fittings?
I don't like rubber oil hoses with screw clamps but this does look like a good install.

Each line has a flare so the hose will not pull off.

Posted By: mooky stinks on 04/22/17 05:21pm

Funny how my last 3 or 4 trucks have had transmission temp gauges and OE coolers and have run between 215 when towing in the summer and 100 in the middle of winter during 100 mile trips. How can it have a 115 degree swing AND have a thermostat. My current truck (new GM 8 speed) does seem to have some sort of thermostat because it has never gone over and hovers at 190 in summer even when towing. But when not towing during the winter it will run anywhere between 120-140 and stay there for a 100 mile trip?

2020 F150 XL Screw 4x4 6.5”box
3.5 ecoboost Max tow HDPP
7850 GVW. 4800 RAWR
2565 payload

2020 Cougar 29RKS 5th wheel

Posted By: falconbrother on 04/22/17 06:02pm

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. It 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.

Posted By: lawrosa on 04/22/17 07:24pm

falconbrother wrote:

Im sure thats why GM put the plug there. They know the transmissions run hot..

If I start my truck and let it idle the temps rise to 200f without even driving. Even with the cooler.

Engine temps never get hot but I noticed cooler engine temps since I put the trans cooler in..

I need to ride around more to give more detailed info..

And of course tow this summer..

Posted By: ulvik on 04/22/17 08:12pm

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.

2018 Ram 3500 DRW
2015 Heartland Big Country 3650RL
Great Smokey Mountains

Posted By: FunTwoDrv on 04/23/17 07:43am

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

Posted By: lawrosa on 04/23/17 08:03am

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..

[image]

Installed

Posted By: lawrosa on 04/23/17 08:05am

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..

Posted By: FunTwoDrv on 04/23/17 01:22pm

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

Posted By: falconbrother on 04/23/17 04:25pm

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.

Posted By: falconbrother on 04/23/17 04:29pm

falconbrother wrote:

I realized that I had a misspelling and tried to correct it and this is the result.. Whatev's..

Posted By: falconbrother on 04/26/17 06:49pm

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.

Posted By: BenK on 04/26/17 07:11pm

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:

Posted By: ktosv on 04/27/17 04:18pm

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.

Kevin and my...
Wife and six kids
2017 Suburban (5.3L/6A/3.08)
6x12 Enclosed Utility

Sold...2011 Express 3500 (6.0L/6A/3.42)
Sold...2010 Passport Ultra Lite 2910

Print | Close