Transmission Coolers

[YukonRog]

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]

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]

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:

 

[mikeyss]

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

 

[YukonRog]

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.

 

[YukonRog]

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?

 

[mikeyss]

Did you bypass the radiator?

No, I didn't bypass the radiator only because of how cold it gets at times here in CO

 

[Geotrash]

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]

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.

 

[YukonRog]

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.

 

[Bill 1960]

For $400 I think you could have a new radiator and remain OEM design if you so choose.

I get why transmission shops fear a compromised cooler, but it’s nuts to me that they don’t believe a cooler can be cleaned out. And if there’s some lingering fear of contamination, a Magnefine filter in the cooling return line would be inexpensive insurance and guarantee nothing is going back into the pan from the radiator circuit.

PS- my GM reman was dealer installed and THEY were satisfied to clean out the existing cooler and reuse it. And warranty it for 100k. There was no concern stated about the cooler at all.

 

[YukonRog]

For $400 I think you could have a new radiator and remain OEM design if you so choose.

I get why transmission shops fear a compromised cooler, but it’s nuts to me that they don’t believe a cooler can be cleaned out. And if there’s some lingering fear of contamination, a Magnefine filter in the cooling return line would be inexpensive insurance and guarantee nothing is going back into the pan from the radiator circuit.

Exactly my thoughts. Thanks for the filter idea too, I'll look into that.

 

[Bill 1960]

One more thought- I have used the Magnefine/ Raybestos filters personally. I think it’s a great product. But the capacity is small. I wouldn’t put one on a trans and leave it permanently, or too long, because I’d be concerned about flow restriction. I’d swap it out after break in and regularly thereafter, or remove it after break in was done.

For a higher capacity solution there are filter mounts and spin-on filters for applications that demand it. I don’t consider them beneficial for most trans applications.

 

[YukonRog]

One more thought- I have used the Magnefine/ Raybestos filters personally. I think it’s a great product. But the capacity is small. I wouldn’t put one on a trans and leave it permanently, or too long, because I’d be concerned about flow restriction. I’d swap it out after break in and regularly thereafter, or remove it after break in was done.

For a higher capacity solution there are filter mounts and spin-on filters for applications that demand it. I don’t consider them beneficial for most trans applications.

That's funny because after I read your first suggestion about the filter I looked them up and came up with the same "change out after break in" philosophy. But I'd cut that sucker open to inspect exactly what was inside. This guy is worried about his 3 yr warranty and the cooler bypass is what he believes in. I don't since we go below 32⁰ in the winter and occasionally tow a small trailer either a 600lb camping box or sometimes a 6 x 12 single axle cargo tralier that I think weighs 1200lb. Not to mention what my wife puts inside. (Furniture)

 

[swathdiver]

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.

Hayden's are the gold standard and at one time were OE suppliers to GM for radiators and the coolers and maybe still are.

If you are concerned about the cooler in the radiator, you might consider replacing the radiator.

 

[YukonRog]

I am currently searching for a radiator and auxiliary cooler. OE replacements. I really don't like the idea of bypassing the radiator with a huge Tru Cool 40,000. Especially with winter coming on. I just went over Donner Pass to Reno between storms and it made me think about the Yukon making that trip with that cooler out front. The fluid would never get warm! So, the radiator cooler lines and the auxiliary cooler are compromised. I did another flush and got metal out this time. So, new radiator and cooler. And I'm thinking new lines too. Problem I'm having is getting the right part numbers. I cross posted a question in the General section asking for a site where I can get p/n's. Then the transmission shop would have nothing to complain about, except maybe losing a little money on his upsell. Any help would be appreciated. I can find any Harley p/n I want but I haven't found a site for GM parts yet.

 

[gooffeyguy]

My Derale stacked plate cooler is only half the size of the TruCool, but it's twice as thick (2") and rated 37k btu.

 

[latvius]

You can get the TruCool with a thermostat and for how much a transmission costs I would replace the radiator if you are going to keep it in the loop. The shop should be satisfied with for warranty concerns.

 

[YukonRog]

You can get the TruCool with a thermostat and for how much a transmission costs I would replace the radiator if you are going to keep it in the loop. The shop should be satisfied with for warranty concerns.

I think this guy just wants to upsell me. He says the Tru-Cool 40k is $225 plus 1.5 hrs labor. I don't want that huge of a overkill cooler in strictly bypass. So I'm replacing the radiator, all 3 lines, and the OE Auxiliary Cooler. He should be happy with the transmission and a virgin system.

 

[Pat11784]

For $400 I think you could have a new radiator and remain OEM design if you so choose.

I get why transmission shops fear a compromised cooler, but it’s nuts to me that they don’t believe a cooler can be cleaned out. And if there’s some lingering fear of contamination, a Magnefine filter in the cooling return line would be inexpensive insurance and guarantee nothing is going back into the pan from the radiator circuit.

PS- my GM reman was dealer installed and THEY were satisfied to clean out the existing cooler and reuse it. And warranty it for 100k. There was no concern stated about the cooler at all.

I mounted the cooler horizontally below the radiator between the bumper and radiator support so it doesn't impede airflow to the intercooler.