Transmission Coolers

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.

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
It's been suggested I have a Tru-Cool 40,000 Transmission Cooler installed as a "Stand Alone" unit completely bypassing the radiator and factory supplemental cooler on my '05 Yukon simply because the transmission that is being replaced had so much metal in it. Has anyone done this, and how has it worked out for you?
 

Bill 1960

Testing the Limits
Joined
Dec 17, 2020
Posts
1,480
Reaction score
2,857
I believe @Geotrash has a big thread on trans cooling.

I have read some reports that the big Tru-Cool reduces airflow to the radiator enough to interfere with engine cooling.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,100
Reaction score
25,030
Location
Treasure Coast, Florida
It's been suggested I have a Tru-Cool 40,000 Transmission Cooler installed as a "Stand Alone" unit completely bypassing the radiator and factory supplemental cooler on my '05 Yukon simply because the transmission that is being replaced had so much metal in it. Has anyone done this, and how has it worked out for you?
This is my opinion but I would not be inclined to run the cooler without the main cooler. The transmission cooler in the radiator helps to warm up the transmission which is especially helpful during colder weather.

You might consider pumping fluid through the radiator mounted cooler to clean any contaminants out of it and the lines before using it again. Use a drill pump like this one but NOT this one from Harbor Freight:
ab33525d08d6e5fb8d27136e95%2F6%2F2%2F62783_zzz_500.jpg
 

mikeyss

Full Access Member
Joined
Nov 11, 2011
Posts
1,611
Reaction score
3,001
Location
Longmont, Colorado.
I run the tru-cool 40k cooler in the space the original cooler was, and my engine runs the same temp, and my trans runs between 100-150 depending on outside temps. I haven't towed more than 1000lbs though
 
OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
This is my opinion but I would not be inclined to run the cooler without the main cooler. The transmission cooler in the radiator helps to warm up the transmission which is especially helpful during colder weather.

You might consider pumping fluid through the radiator mounted cooler to clean any contaminants out of it and the lines before using it again. Use a drill pump like this one but NOT this one from Harbor Freight:
View attachment 353149
That's a good idea on a way to flush the lines. From what I'm seeing, the cooler is a "Low Pressure Drop" type that only allows cold fluid to run in the top couple tubes until it becomes hot and then it runs through the entire cooler.
 
OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
I run the tru-cool 40k cooler in the space the original cooler was, and my engine runs the same temp, and my trans runs between 100-150 depending on outside temps. I haven't towed more than 1000lbs though
Did you bypass the radiator?
 

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
5,490
Reaction score
12,976
Location
Richmond, VA
Several lessons learned by me and others here on this topic. The key points are:

- GM recommends a minimum temperature on the 6L80E of 150°F for normal operation, and with the tru-cool you’ll be lucky to see 130° most days.
- Mounted in front of the radiator, the Tru-cool blocks so much airflow that it creates cooling problems for the radiator engine when towing - even in the spring and fall.
- Plumb the radiator’s water to fluid cooler in line before the aux cooler, regardless of climate. It will warm the fluid when cold and help cool it when hot.
- If not towing, I recommend a smaller cooler than the 40k of mounting it in front of the radiator. If towing, mount a fan forced Derale 13560 or similar below the front bumper.
 

ScottyBoy

Full Access Member
Joined
Jun 27, 2010
Posts
2,565
Reaction score
1,723
Location
Shreveport, La
I considered a Tru-Cool 40k, but it's actually overkill for my truck as I don't tow and I'm not heavily modded. I ended up getting a Hayden 679 which has a 30k rating (still a bit of overkill IMO) and it's a LOT cheaper than a Tru-Cool. I mounted mine in place of the stock trans cooler by making some brackets out of aluminum bar stock. (I removed the brackets and painted them black after I took that picture) Its been on there for 2yrs now and I have had ZERO overheating issues. IMG_20180923_144503693.jpg
 
OP
OP
YukonRog

YukonRog

Full Access Member
Joined
Jun 25, 2020
Posts
594
Reaction score
752
Location
Grass Valley CA
The issue is I believe the shop I have chosen for the transmission replacement is recommending the Tru-Cool 40k since he believes my radiator cooler is compromised from metal sludge. Even though I flushed it and got nothing out of it. He's also very negative about Hayden's. I'm sure he's going for the upsell and the additional $400. We rarely tow with it too. My thinking is OEM would be fine even with maybe a smaller replacement auxiliary cooler. I know the Tru-Cool 40k means 40,000lb gross weight. At this point it's sitting in my driveway while I bang my head against the wall.
 

Forum statistics

Threads
128,786
Posts
1,805,444
Members
91,766
Latest member
GeorgeC

Latest posts

Top