Replace Transmission Cooler with TruCool 40k

[thompsoj22]

Completely unnecessary, IMHO. Normal operating temperatures are 190-200°.

I've done this on multiple occasions, original transmission still shifts perfectly with 180k on it. 20k miles of heavy towing, including the Rockies and the Eisenhower Tunnel.

I f I were you, I'd be a lot more concerned about the rear axle than the transmission. Have you checked its temperature while towing? Have you checked your weights while towing? I'd be willing to bet it's either a) getting really hot, or b) overloaded, or both.

I'd upgrade the rear diff cover to one with cooling fins. I towed lots of heavy stuff with my half-ton Suburban, and it still has the original transmission at 250k miles, but it's on rear end number 4.

You have posted this photo before and i swear that rpm is where are 03 4.8 tahoe had to be to tow our trailer! It was a white knuckle ride for me that i didnt enjoy. I wish i had your confidence in that it wont blow up and likes to rev. Do you think this is truly what the GM engineers envisioned while towing?

 

[intheburbs]

That picture was taken climbing a 7% grade, at 10,000 feet of altitude, with a GVWR a little over 16,000 lbs.

When cruising on flat ground, I'm around 3k.

One need only look at the torque and HP peaks of an engine to see how much it likes to rev.

For my 6.0 (and 6.2), max torque hits a little over 4k,and max HP is right around 6k. That, plus the VVT, tells you these engines are rev-happy.

 

[BG1988]

Heat kills pretty much anything this is a widely accepted fact
having had numerous transmission problems in the past generally thru my own fault I was concerned when I purchased my 2012 awd denali and it consistently had transmission temps in the 200+deg range having come from a 5.3 4wd that would consistently hovering at 180 deg, without towing anything and just driving. I added a deeper transmission pan which gives it 2qt's extra to help cool and added the trucool 40k, my goal was to get the temps down to 160 consistently. doing this met and exceeded that goal.

while driving normally only hitting 152-157F under normal driving conditions with stock cooling 85F temp outside.


2ML70 4 Speed Automatic

it gets to 110F outside over here but i'm sure the fans can handle it...

That picture was taken climbing a 7% grade, at 10,000 feet of altitude, with a GVWR a little over 16,000 lbs.

When cruising on flat ground, I'm around 3k.

One need only look at the torque and HP peaks of an engine to see how much it likes to rev.

For my 6.0 (and 6.2), max torque hits a little over 4k,and max HP is right around 6k. That, plus the VVT, tells you these engines are rev-happy.

If you have the 6.0 or 6.2 or FFV, you should be using at lest 91 Octane
Don't use cheap gas if you can use Chevron or Texaco or Caltex with Techron


if you can get good gas like like Chevron at lest buy some techron and use it on every fill up Don't do what the bottle says every 3k miles

use on every fill up at lest 2 bottles..

 

[Erickk120]

200*F+ seems pretty toasty for me, I would imagine the gaskets and orings inside the tranny would be getting pretty brittle and lose their sealing elasticity over time. A lot of 3-4 clutch failures are due to that very same reason, heat and seals don't go well together. Just because it is fine doesn't mean you can't keep things cooler and give them a chance at a longer life. I drive my truck pretty hard and abuse it I would say, I've killed my rear end once though, Rear ends usually seem to fail to to fluid breakdown, and over loading which is caused by the oils being overheated and what would you guess caused that? Yup excessive heat build up.

 

[intheburbs]

If you have the 6.0 or 6.2 or FFV, you should be using at lest 91 Octane
Don't use cheap gas if you can use Chevron or Texaco or Caltex with Techron


if you can get good gas like like Chevron at lest buy some techron and use it on every fill up Don't do what the bottle says every 3k miles

use on every fill up at lest 2 bottles..

Please show me in any owners manual where the 6.0 requires premium gas.

Hint: You won't find one. You really think fleet managers want a vehicle that requires premium fuel?

Yes, the owners manuals recommend premium for the 6.2.

And I've NEVER used a fuel additive in any of my vehicles. I've also never had fuel-related problems with any of them. The Suburban has 190k miles on it, original engine, and it still purrs like a kitten, and will happily rev to 6000 RPM at full-throttle. I guess it's just luck.

200*F+ seems pretty toasty for me, I would imagine the gaskets and orings inside the tranny would be getting pretty brittle and lose their sealing elasticity over time. A lot of 3-4 clutch failures are due to that very same reason, heat and seals don't go well together. Just because it is fine doesn't mean you can't keep things cooler and give them a chance at a longer life. I drive my truck pretty hard and abuse it I would say, I've killed my rear end once though, Rear ends usually seem to fail to to fluid breakdown, and over loading which is caused by the oils being overheated and what would you guess caused that? Yup excessive heat build up.

Gaskets and o-rings turning brittle at 200° or so? Really? Do some research on fluorocarbon rubber, FKM, tradename Viton, and get back to me.

 

[BG1988]

Please show me in any owners manual where the 6.0 requires premium gas.

Hint: You won't find one. You really think fleet managers want a vehicle that requires premium fuel?

Yes, the owners manuals recommend premium for the 6.2.

And I've NEVER used a fuel additive in any of my vehicles. I've also never had fuel-related problems with any of them. The Suburban has 190k miles on it, original engine, and it still purrs like a kitten, and will happily rev to 6000 RPM at full-throttle. I guess it's just luck.



Gaskets and o-rings turning brittle at 200° or so? Really? Do some research on fluorocarbon rubber, FKM, tradename Viton, and get back to me.

6.2 L LSA

6.2 L LT4
both require 91 or higher


with my 6.0L VVT I get crappy MPG on the road with 87 octane ( a trip threw the mountains)

I can barely get 18MPG since it keeps Searching for gears.. and searching between V4 and V8 mode


Chevron seems to give you what you pay for at the pump.

I get a consistent 26.75MPG to 28.75MPG @ 58MPH with CC. Highway:95% city:5% round trip, on my once a week trip with only Chevron 91 octane fuel..

if you want very specific numbers
it's 31.50-32.50MPG on the down hill side
and 22.25-23MPG on the up hill side


even though the DIC says 18.4MPG that is from the previous Owner it was last reset 31,550 miles ago..

 

[Erickk120]

Gaskets and o-rings turning brittle at 200° or so? Really? Do some research on fluorocarbon rubber, FKM, tradename Viton, and get back to me.[/QUOTE]

I still stand behind what I said. Just because something is heat/wear resistant, doesnt mean heat/wear proof. Over its life span and constant heat cycles the rubber will lose its properties and deterioate. Idc what a book says, Otherwise builders would never see molded piston/seal failures in older/high mileage units. In high performance use of a stock unit the main cause of failure is overheat, caused by the clutch packs/torque converter. As far as operating range I would rather stay way under it than closer to its max. Anything over 200f and I would be looking for a better cooling solution. 20k of towing isnt much to brag about, I would be hard pressed if my tranny died from that. Transmissions are just glorified hydroulics and those are always ran closer to mid range than max range. GM would like you to believe 240f is normal but since when have they been honest?

 

[intheburbs]

I still stand behind what I said. Just because something is heat/wear resistant, doesnt mean heat/wear proof. Over its life span and constant heat cycles the rubber will lose its properties and deterioate. Idc what a book says, Otherwise builders would never see molded piston/seal failures in older/high mileage units. In high performance use of a stock unit the main cause of failure is overheat, caused by the clutch packs/torque converter. As far as operating range I would rather stay way under it than closer to its max. Anything over 200f and I would be looking for a better cooling solution. 20k of towing isnt much to brag about, I would be hard pressed if my tranny died from that. Transmissions are just glorified hydroulics and those are always ran closer to mid range than max range. GM would like you to believe 240f is normal but since when have they been honest?

What on earth makes you think that GM, or anyone, thinks 240° F is normal? I took that picture to illustrate the most extreme case I'd ever expose to my truck. Pulling an 8600-lb trailer in Colorado, on I-70 eastbound, on a stupid-steep grade, on the approach to the Eisenhower Tunnel (over 11,000 feet in altitude) , during the summer, with the A/C on. And, honestly, I post it specifically to make people's heads explode.


So let's review some points:

1) I sell seals and gaskets in my day job. I do a lot of design work with Tier 1 suppliers, including the transmission manufacturers like Borg Warner, ZF, and Aisin. I'm a distributor for the world's largest manufacturer of O-rings, and we're their second-largest customer. I've been in the seal business for 26 years, so I know a little bit on the subject. When the engineers at these companies have technical questions about O-rings or seals, they call me.

2) GM claims that normal operating temperature for the 6L80/90 is 190-200° F, not 240° F. And the "trans hot, idle engine" warning comes on at 265° F. My two GMT900 trucks generally run about 100° over ambient temperatures. So the only time they get that warm is during the summer.

3) A good friend of mine worked at GM as a transmission validation engineer. He specifically worked on validating the 6L80/90. I've followed his guidance, since he might actually know a little more about these transmissions than I do.

4) Yes, heat is generally bad. But hydraulic fluids are constantly improved and part of their design parameters is specifically to be as seal-friendly as possible. Plus, Dex6 is/was a significant step forward over Dex3 with regards to thermal capabilities.

5) Since you likely didn't do any searching, I'll share some facts on Viton. It was first developed by Dupont. Max operating temperature of this rubber is 400°F. It's a highly-fluorinated material, meaning most of the hydrogen atoms on the polymer chains have been replaced by fluorine. This means the rubber is much more durable and is better able to resist chemical attack and thermal breakdown (like heat cracking and embrittlement) . Just about all the transmission manufacturers use Viton now.

6) I'll repeat: I have an 11 year-old truck that I work very hard, and is frighteningly all-original (including the trans cooling system) with 190k miles on it. I also change the fluids religiously. I'm not quite sure how one can improve on my results, so I'll just keep doing what I'm doing.

And lastly, one little pedantic point - if you're trying to sound knowledgeable about something, trying to convince people that your opinion is valid, make sure you spell a key word like "hydraulics" properly.

 

[Erickk120]

Cool I guess it works, and as expected its not a temp you'd want to cruise around for prolonged distances.

Point 1 Hope you are not the one advising dorman, top seal guys there. Its a joke do t let it get it to you.
That aside you are pretending to tell me that age/heat cycles do not affect the plastics in accumulators and compounds used on seals over a prolonged time/temp, note I'm referring to years of use and abuse, just because the guys at dupont say its ok for up to 400f and -4f does that mean it wont break down overtime. I guess you'd know how each temp range would affect it if any. If you tell there is no difference between 150-180F and 180-210F+. Idk what to tell you. As posted early resistance doesnt equals proof. Now it'd be more interesting to see actual testing, between oem vs after market cooler, and see the effects that has through the lifetime of the unit. While the seals can take this for prolonged times it doesnt mean I cant try to do better.

Point 2 GM, I'm sure you too would go with life time fluid if GM said so too, its a ford joke. 190f to 200f is on the hot side. The trans 100 over engine temp is only due to the cheap radiator gm uses, in combo with the trans which makes sense to keep things warm in cold climates. At the same time mishimoto makes a sturdier aluminum one that keeps things cooler without a fluid mixture possibility in the future.
There is a lot of flaws with these trucks that could be improved upon and not limited to transmission temps.

3 6l80/90 are strong trans compared to the earlier disgrace the 60e was. The 60e is the easiest transmission to fry in a full size suv.
No idea how I know that.

4 yup

5 I looked into it, everything has limitations. Which is the reason every 15 year old plus car leaks oil if it has been properly driven.

6 have had many gm products from early 4l60e's to 4l80e's nothing new past 07.

Mileage has varied from as low as 160ish bad sunshell, aka GM cheap shells. To as high as 320k on a 07 savana with 4l80e and cooler, sold it running with plenty of life, engine leaked from old seals. To one 60e with 280k easy miles they were starting to slip bad though. To lemons slipping at 140k. Mixed results for sure.

Last point is more to do with research from actual reputable builders that see how things perform in the real world and improve upon GM's flaws. Ask every single one of them and they will always recommend a cooler, idk why we are even arguing this. While it isnt necessary for the average grocery getter, it doesnt harm to have one and be able to push a vehicle harder.

I'm not doubting you at all as far as the seal qualities etc... What I protest is just saying that if OEM isnt broke dont fix it, when it can be improved upon.

Whats the highest mileage vehicle you've had with a stock unit? 200k should be the min standard for a transmission if taken care of. Now that is not a problem for the beefier new generations but it was a common problem with previous ones. Isnt a mediocre cooler standard now a days?

 

[intheburbs]

Ok, I'm not doing this any more. Partially because I really can't tell if you're serious, or trolling. Comments like "The trans 100 over engine temp is only due to the cheap radiator gm uses," and "research from actual reputable builders that see how things perform in the real world and improve upon GM's flaws." And I'm not even going to go into advances in rubber/polymer technology. You also admit you only drive older vehicles So, in effect, I'm debating smart phones with someone who uses a flip phone.

I said 100 over ambient, as in the outside temperature, not the engine. If the temperature of the air, you know, outside when you walk out a door in your house, is 70°, then if I drive my trucks long enough, the trans temps will eventually get to about 160-170°.

And with the second quote, are you suggesting or do you believe, that GM does no/very little testing of their vehicles and subcomponents? I'd trust a GM engineer long before I'd trust some shadetree mechanic/builder. Sure, if I was building a 1200-hp drag car, I'd listen to the builder. But for treating/maintaining my mostly-stock vehicle? I'll listen to GM. Sure GM is trying to maintain profitability and reduce costs, but they're also not trying to put out junk. And many flaws like AFM are due directly to stupid government regulations trying to force the technology. Just last year, my friend who's the transmission validation engineer, was complaining about having to do 100 consecutive clutch-drop full-throttle 1/4 mile runs with hard braking back to zero at the end of each run. This was on a Camaro ZL-1. Do you think any owner would do that? Have you ever been to Pikes Peak or Death Valley, and seen the instrumented testing mules? For example, there are actual, written test procedures that utilize "Arizona Road Dirt." Yes, specifically dirt/dust from Arizona. So if I have a power steering unit, I have to test it with Arizona road dirt to make sure the seals don't allow the dust to be ingested.

Yes, Ford's transmission policy is asinine. I have a 2015 Taurus that has the "sealed unit" transmission. But it's a company car, so I really just don't care. I guess I just assumed that's for their cars. If they now do that with the trucks that's just stupid.

My friend owns my '01 Burb, wearing its fourth rear axle because I broke three of them towing. 275k miles, original engine and transmission. Fortunately, I'm well-enough off that I don't have to drive vehicles forever, so I rarely keep them past 200k. I'm only driving the Suburban 5k or so per year, but I'll be looking to replace it in the next few years. But I will say that in my entire adult life, over 30 years and several dozen vehicles, I've never had a major transmission or engine failure. I guess I'm just lucky.

And with this, I'm checking out of this thread.