UR opinion, extra transmission cooler..

[falconbrother]

I pulled the grill on my (5.3 Liter, 4L60e transmission) Suburban to install an oil cooler and there's a factory oil cooler mounted behind the grill already. I traced the line from the return side of the radiator to the cooler then to the transmission. It's definitely a secondary transmission oil cooler. I have considered installing the the one I bought along with the factory secondary but, now think I probably don't need it. Any opinions?

[Terryallan]

RPreeb wrote:

Terryallan wrote:
Nope you don't need it. And to be honest. You want the transmission running at temp. Too cool can be a problem. could keep the trany from changing gears correctly. They change differently before they warm up, at least mine does. Won't go into OD before it warms up.

That seems a bit off to me. I hit the highway within 5 blocks of leaving the garage, and my Ecoboost F-150 shifts to 6th gear as soon as I pass about 55 or 60, as long as I'm not accelerating hard. The transmission temp gauge hasn't even started to move yet (even the engine temp hasn't started to register).

For the OP, if you already have one, then I doubt that adding a second one would be necessary.

that is the way it was designed. would not drop into OD before the trany reached operating temp. You can argue with Ford. but it worked perfectly for 13 years.

As for the cooler. Some have suggested putting one inline BEFORE the radiator. WHY? The fluid will be the same temp as the engine coolant when it comes out of the radiator, no matter how many coolers are installed before the radiator. Transmission cooler only work when they are AFTER the radiator.

[Turtle_n_Peeps]

WTP-GC wrote:

Turtle n Peeps wrote:

WTP-GC wrote:

Turtle n Peeps wrote:


Even my 4L80E in my 93 diesel won't lock up until it reaches temp. There is a reason there is stats in tranny's. And no, there is nothing wrong with it.

I had a 4L80E on a gasser that went into OD regardless of the trans temp. So where does that leave us 😉

I suppose its not accurate to suggest that all vehicles act the same way. I would not argue with someone who suggests that a particular vehicle won't go into OD before reaching temp. However, in my varied experience, I've had had this issue. I'm not aware of any common consumer 1/2 ton to 1 ton truck that has been produced within the last decade or 2 that acts this way.

The last three post on page one will explain what you need to know.

Let's make sure we're not confusing the torque converter with Overdrive. I'm talk about OD, but it looks like you're referencing the torque converter.

Yes, I'm talking about TC lockup. Thank you!

[RPreeb]

Terryallan wrote:
Nope you don't need it. And to be honest. You want the transmission running at temp. Too cool can be a problem. could keep the trany from changing gears correctly. They change differently before they warm up, at least mine does. Won't go into OD before it warms up.

That seems a bit off to me. I hit the highway within 5 blocks of leaving the garage, and my Ecoboost F-150 shifts to 6th gear as soon as I pass about 55 or 60, as long as I'm not accelerating hard. The transmission temp gauge hasn't even started to move yet (even the engine temp hasn't started to register).

For the OP, if you already have one, then I doubt that adding a second one would be necessary.

[WTP-GC]

Turtle n Peeps wrote:

WTP-GC wrote:

Turtle n Peeps wrote:


Even my 4L80E in my 93 diesel won't lock up until it reaches temp. There is a reason there is stats in tranny's. And no, there is nothing wrong with it.

I had a 4L80E on a gasser that went into OD regardless of the trans temp. So where does that leave us 😉

I suppose its not accurate to suggest that all vehicles act the same way. I would not argue with someone who suggests that a particular vehicle won't go into OD before reaching temp. However, in my varied experience, I've had had this issue. I'm not aware of any common consumer 1/2 ton to 1 ton truck that has been produced within the last decade or 2 that acts this way.

The last three post on page one will explain what you need to know.

Let's make sure we're not confusing the torque converter with Overdrive. I'm talk about OD, but it looks like you're referencing the torque converter.

[Turtle_n_Peeps]

WTP-GC wrote:

Turtle n Peeps wrote:


Even my 4L80E in my 93 diesel won't lock up until it reaches temp. There is a reason there is stats in tranny's. And no, there is nothing wrong with it.

I had a 4L80E on a gasser that went into OD regardless of the trans temp. So where does that leave us 😉

I suppose its not accurate to suggest that all vehicles act the same way. I would not argue with someone who suggests that a particular vehicle won't go into OD before reaching temp. However, in my varied experience, I've had had this issue. I'm not aware of any common consumer 1/2 ton to 1 ton truck that has been produced within the last decade or 2 that acts this way.

The last three post on page one will explain what you need to know.

[WTP-GC]

Turtle n Peeps wrote:


Even my 4L80E in my 93 diesel won't lock up until it reaches temp. There is a reason there is stats in tranny's. And no, there is nothing wrong with it.

I had a 4L80E on a gasser that went into OD regardless of the trans temp. So where does that leave us 😉

I suppose its not accurate to suggest that all vehicles act the same way. I would not argue with someone who suggests that a particular vehicle won't go into OD before reaching temp. However, in my varied experience, I've had had this issue. I'm not aware of any common consumer 1/2 ton to 1 ton truck that has been produced within the last decade or 2 that acts this way.

[Turtle_n_Peeps]

WTP-GC wrote:

Terryallan wrote:
Nope you don't need it. And to be honest. You want the transmission running at temp. Too cool can be a problem. could keep the trany from changing gears correctly. They change differently before they warm up, at least mine does. Won't go into OD before it warms up.

ScottG wrote:
I would not add it unless you know for a fact it's getting too hot. You can over cool the fluid.

If it won't go into OD until it warms, then something aint workin right. I've never owned a vehicle that acted that way. Of the 3 major brands, I've owned compact, half ton and heavy duty trucks from 1987 to 2017 year models that never did this (except I've never owned a S-10).

I see that the "don't run your transmission too cold" theory has once again shown up. A while back on this forum, an actual transmission engineer totally dispelled this myth with proof from case studies. Also, FWIW, this topic is never discussed on the Ford or Ram forums I read. I've never seen this anywhere except on the RV forum.

I would replace the factory cooler with a high quality aftermarket unit if you're seeing concerning temps or if you intend on going more heavy-duty with your towing characteristics. Most of the OEM coolers placed on half-ton trucks/SUV's aren't very capable. But as others have said, if you're getting normal temps I wouldn't touch it.

Even my 4L80E in my 93 diesel won't lock up until it reaches temp. There is a reason there is stats in tranny's. And no, there is nothing wrong with it.

[WTP-GC]

Terryallan wrote:
Nope you don't need it. And to be honest. You want the transmission running at temp. Too cool can be a problem. could keep the trany from changing gears correctly. They change differently before they warm up, at least mine does. Won't go into OD before it warms up.

ScottG wrote:
I would not add it unless you know for a fact it's getting too hot. You can over cool the fluid.

If it won't go into OD until it warms, then something aint workin right. I've never owned a vehicle that acted that way. Of the 3 major brands, I've owned compact, half ton and heavy duty trucks from 1987 to 2017 year models that never did this (except I've never owned a S-10).

I see that the "don't run your transmission too cold" theory has once again shown up. A while back on this forum, an actual transmission engineer totally dispelled this myth with proof from case studies. Also, FWIW, this topic is never discussed on the Ford or Ram forums I read. I've never seen this anywhere except on the RV forum.

I would replace the factory cooler with a high quality aftermarket unit if you're seeing concerning temps or if you intend on going more heavy-duty with your towing characteristics. Most of the OEM coolers placed on half-ton trucks/SUV's aren't very capable. But as others have said, if you're getting normal temps I wouldn't touch it.

[ktosv]

When towing a 7200# GVWR TT with a 2005 Suburban with the 5.3/4L60E/3.42 combo I didn't ever see any alarming tranny temps.

I only towed in drive (3rd). On mine, Tow Haul prevented shifting into OD under 60mph and increased that under load. The torque converter also locked up in drive on mine.

[falconbrother]

Dang..

[Rbertalotto]

Many transmissions will not lock up the torque converter except in the highest gear. All other times you are "running on juice". This is where transmissions really overheat. Driving secondary roads in a lower gear. Pulling up a mountain road in lower gear.

Contact BD Diesel as they make kits that allow the TC to lock up in all but first gear. Transmission temperature issue solved!

I recently went whole hog and installed one of their Tow/Haul transmissions that locks up in all gears. I used to see 260 degrees transmission temperature on a hill that I frequent. Now I NEVER see over 175 degrees no matter the hill or speed I'm driving. I like driving backroads hauling my camper and the transmission temps used to climb. Not any longer...Love it!

[kevden]

falconbrother wrote:

kevden wrote:
I am towing at or over the rating of our Yukon, so I added a cooler in line with the factory cooler to help keep the transmission temp down. To mount them, I bolted strips of aluminum in front of the radiator one at the top one at the bottom. Moved the oem cooler to the passenger side and mounted the new one on the drivers side. The new one has an electric fan that I wired to an adjustable thermostat. I can definitely see lower temps when adjusting the thermostat down.
The engine oil goes through the drivers side of the radiator, I have though about putting a cooler on that line as well.
If you don't already have one, you should get a guage to monitor the trans temp. A scan tool would work, or a tuner with a display (Bully Dog, Diablosport, Edge)
Also, from what I have read online, the overdrive gear in the 4L60 should not be used when towing. Wish I had learned that before killing one lol.

Doesn't the "tow/haul" feature keep the transmission out of overdrive?

Not on my 2003 Yukon 2500. Didn't on my 2005 Avalanche 1500 either. It only holds the gear longer and firms the shift.

[falconbrother]

kevden wrote:
I am towing at or over the rating of our Yukon, so I added a cooler in line with the factory cooler to help keep the transmission temp down. To mount them, I bolted strips of aluminum in front of the radiator one at the top one at the bottom. Moved the oem cooler to the passenger side and mounted the new one on the drivers side. The new one has an electric fan that I wired to an adjustable thermostat. I can definitely see lower temps when adjusting the thermostat down.
The engine oil goes through the drivers side of the radiator, I have though about putting a cooler on that line as well.
If you don't already have one, you should get a guage to monitor the trans temp. A scan tool would work, or a tuner with a display (Bully Dog, Diablosport, Edge)
Also, from what I have read online, the overdrive gear in the 4L60 should not be used when towing. Wish I had learned that before killing one lol.

Doesn't the "tow/haul" feature keep the transmission out of overdrive?

[falconbrother]

intheburbs wrote:
Swap out your gauge cluster for an HD cluster, and you'll now have a working trans temp gauge. Use that as a guide as to whether or not you need to install an aux cooler.

I pulled trailers as heavy as 7,000 lbs with my '01 Suburban 1500, and never saw any trans temp that caused me concern. And that includes towing in the Rockies.

And yes, avoid 4th when towing. 3rd is a 1:1 ratio, so it puts the least stress on the transmission. Took a little while to get comfortable with the engine at 3000 RPM while cruising, since the truck had 4.10 gears. But I logged over 15,000 miles towing like that, and the truck now has 235k miles on it with the original engine and transmission.

I have read that the extra RPMs are helpful to keep it cool in the mountains. In my old motorhome I would keep the RPMs up on steep climbs and it did fine. Keeps the water pump moving water faster or something like that..

The factory transmission oil cooler looks like it's a good size and good quality. Better than the aftermarket one I bought, which I'm sure would still be fine.