Which aux trans cooler to get.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Dutch Rutter

Full Access Member
Joined
Aug 13, 2013
Posts
1,070
Reaction score
1,185
Location
Independence, Or
First Name
Joshua
Truck Year
1984
Truck Model
K20
Engine Size
5.7
Alright all, I've come to the conclusion that if I'm going to be towing this summer I need to get a better aux cooler for my trans. Gave a search on the forum which lead me to the tru-cool line which seem great but how much cooler is too much? My GVWR is only 8600 but I would like to have as much cooling to it as possible without over kill. Since the tru-cool has their thermal bypass pieces (part# LNG-4739P6) this is supposed to bypass the aux cooler when the fluid isn't warm enough. Don't know if anyone has used these.

Currently I am running this cheap thing. In line with my in-radiator "cooler"
https://www.amazon.com/gp/product/B009TACG54/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
I don't feel this will be sufficient even with my high CFM SPAL fan, a 60* day on the highway (not pulling or hauling) it does great trans sits at 140*, in traffic though it climbs to 180* and I can only seeing that get worse come summer.

This list the LPD line
http://www.trucool.com/products/tru-cool-lpd
Figure the LPD4544 with its rated 22000 GVWR would be enough. Fitting the 9.5x11.3/4 size wouldn't be hard.

Then there is their max line.
http://www.trucool.com/products/tru-cool-max
These monster coolers I was thinking the GVWR 30000, LPD4921* with the bypass piece and two e-fans on the front would be total overkill but would definitely make my trans temp lower no matter what I throw at it. Would have to get slightly creative to fit it but I'm confident it could be done.

What do we think, anyone running these?
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,789
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
Alright all, I've come to the conclusion that if I'm going to be towing this summer I need to get a better aux cooler for my trans. Gave a search on the forum which lead me to the tru-cool line which seem great but how much cooler is too much? My GVWR is only 8600 but I would like to have as much cooling to it as possible without over kill. Since the tru-cool has their thermal bypass pieces (part# LNG-4739P6) this is supposed to bypass the aux cooler when the fluid isn't warm enough. Don't know if anyone has used these.

Currently I am running this cheap thing. In line with my in-radiator "cooler"
https://www.amazon.com/gp/product/B009TACG54/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
I don't feel this will be sufficient even with my high CFM SPAL fan, a 60* day on the highway (not pulling or hauling) it does great trans sits at 140*, in traffic though it climbs to 180* and I can only seeing that get worse come summer.

This list the LPD line
http://www.trucool.com/products/tru-cool-lpd
Figure the LPD4544 with its rated 22000 GVWR would be enough. Fitting the 9.5x11.3/4 size wouldn't be hard.

Then there is their max line.
http://www.trucool.com/products/tru-cool-max
These monster coolers I was thinking the GVWR 30000, LPD4921* with the bypass piece and two e-fans on the front would be total overkill but would definitely make my trans temp lower no matter what I throw at it. Would have to get slightly creative to fit it but I'm confident it could be done.

What do we think, anyone running these?
These are what I’ve run on the last couple builds
https://www.summitracing.com/parts/...eH0xbgiUKWVEGu9d5yKNOwXL0oUkR_TsaAn78EALw_wcB
You must be registered for see images attach
You must be registered for see images attach
 

Dutch Rutter

Full Access Member
Joined
Aug 13, 2013
Posts
1,070
Reaction score
1,185
Location
Independence, Or
First Name
Joshua
Truck Year
1984
Truck Model
K20
Engine Size
5.7
@Honky Kong jr That looks super clean btw! Those are smaller in size then my current el-cheapo crap setup. I know that the stacked plate style is more effective then the tube and fin, but wow. You sold me. I'll get a kit ordered asap Thanks.
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,789
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
@Honky Kong jr That looks super clean btw! Those are smaller in size then my current el-cheapo crap setup. I know that the stacked plate style is more effective then the tube and fin, but wow. You sold me. I'll get a kit ordered asap Thanks.
:waytogo:
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,977
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73

74 Shortbed

Full Access Member
Joined
Aug 12, 2013
Posts
6,306
Reaction score
1,410
Location
*
First Name
*
Truck Year
*
Truck Model
*
Engine Size
*
That's the only type I ever use....
 

Dutch Rutter

Full Access Member
Joined
Aug 13, 2013
Posts
1,070
Reaction score
1,185
Location
Independence, Or
First Name
Joshua
Truck Year
1984
Truck Model
K20
Engine Size
5.7
Just got it ordered. Like Rusty said this other is just garbage I'm thinking it does more harm then good. When I bought it cheap was the idea. Just farther enforces the idea of pay for what you get. I'll throw up some pictures and results once I receive it and mount it.
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,158
Reaction score
15,957
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350
That's what I've used for over 30 years. Sturdy, reliable and efficient.
 

ballencd

Full Access Member
Joined
Aug 30, 2013
Posts
106
Reaction score
46
Location
Columbus, NC
First Name
Charlie
Truck Year
1988/1991/1983
Truck Model
V10 Suburban/V1500 Suburban/M35 bobbed w/dump
Engine Size
5.7/5.7/LDT 465-1c
I've heard that you totally bypass the transmission internal to radiator trans cooler for best results when installing this kind of auxiliary cooler. Is that correct?
 

Dutch Rutter

Full Access Member
Joined
Aug 13, 2013
Posts
1,070
Reaction score
1,185
Location
Independence, Or
First Name
Joshua
Truck Year
1984
Truck Model
K20
Engine Size
5.7
I've heard that you totally bypass the transmission internal to radiator trans cooler for best results when installing this kind of auxiliary cooler. Is that correct?

It will run cooler with it being bypassed. however you don't want your trans fluid to run too cool. The idea is to keep it in its optimum temp range. So when its cold out the idea is the coolant in the radiator will warm up faster then the trans fluid, so with using the in radiator cooler it will heat the trans fluid to a usable temp faster then just a cooler which has bypassed the radiator cooler. In my area I see cold days and I see hot days so I want both. The radiator cooler helps bring the fluid to temp while the remote cooler helps dissipate heat when its being ran.

Think I explained this right, @HotRodPC would do better I'm sure.
 

4WDKC

Full Access Member
Joined
Jan 27, 2016
Posts
2,366
Reaction score
1,090
Location
Southern Florida
First Name
Kacy
Truck Year
1987
Truck Model
V10
Engine Size
350

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,735
Reaction score
9,532
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
I did NOT say that.

think about the Law of Diminishing Returns, an economic concept that asserts that after a certain point further investment (or effort) does not increase your expected return. In fact it can reduce it.

An aux·il·ia·ry transmission cooler is only effective to a point, after which one has wasted both time and money.

xc_hide_links_from_guests_guests_error_hide_media

In my opinion there is little to no need nor benefit investing in anything bigger or more expensive than the Hayden 1205 of which I own three.
It's a high quality product that is a standout exceptional buy for the money.

I DID say that.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,735
Reaction score
9,532
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
Additionally, for the record, I run two coolers in my square bodied trucks. The factory cooler in the radiator first and the Hayden afterwards, in a series. The additional fluid capacity has a great impact on cooling efficiency and recieves little mention.
The cooler in my SS functions solo, the transmission cooler lines in my radiator are unused.
I too subscribe to the idea that transmission fluid can be too cool especially on the street, stoplight to stoplight.
When running full-throttle a 1/4 mile at a time, more extreme cooling is necessary and heat transfer from the radiator's cooler is unwelcomed but on the street -in my opinion- it helps maintain reasonability.

Everything in moderation
 

vkh

Full Access Member
Joined
May 21, 2015
Posts
436
Reaction score
138
Location
Western Montana
First Name
Var
Truck Year
1981
Truck Model
C2500
Engine Size
454
Additionally, for the record, I run two coolers in my square bodied trucks. The factory cooler in the radiator first and the Hayden afterwards, in a series. The additional fluid capacity has a great impact on cooling efficiency and recieves little mention.
The cooler in my SS functions solo, the transmission cooler lines in my radiator are unused.
I too subscribe to the idea that transmission fluid can be too cool especially on the street, stoplight to stoplight.
When running full-throttle a 1/4 mile at a time, more extreme cooling is necessary and heat transfer from the radiator's cooler is unwelcomed but on the street -in my opinion- it helps maintain reasonability.

Everything in moderation

By chance do you have a technical explanation or article explaining why more fluid capacity would improve efficiency? Not trying to be difficult, just curiosity.
 

Latest posts

Forum statistics

Threads
41,857
Posts
903,629
Members
33,370
Latest member
mitchell1128
Top