Time to install a transmission cooler

[1engineer]

Agree on all points. Most post's I've read say tranny life drops off quickly with sustained temps over 170. Even though the transmission will run into the low 200's like it's no big deal. I'm going to try to get a towing temp of around 170 ish after the cooler install.

You actually have documentation?
From a credible source? (hint: forum posts don't count unless it is from one specific person who manufactures transmissions for Toyota.)
On this specific transmission?
Using the factory fluid?
If so, please post!

My opinion based on past design experience? 200-230 is not going to hurt the life one bit. Again, this is not a 1970's Buick with a Turbo 400 transmission. Getting a tow temp down to 170 would require a heat exchanger of epic proportions.

Now, if I towed 3500-5000 lbs daily with my 4Runner I would get the fluid changed every 50K or so. Otherwise? Waste of money IMO.

There's a reason OEM vehicles don't have real gauges in them anymore lol. People worried too much about things they didn't understand.

 

[phillyd2]

Like Jeff I too stopped worrying about it despite doom and gloom from the forum. Even with a tran cooler installed I still see 210+ readings when towing the boat, Atvs or trailer but it usually kicks down lower.

 

[JeremyB]

Still getting a feel of my boat (~4400 lbs), but two weekends ago I got up to 220 deg. pan and 245 deg. converter going over a 870 ft, 5.5% grade climb while doing 45-50. Not enough to make me want an extra cooler yet.

 

[Jeremy556]

That was a typo. 6500.


Does the Tacoma hitch actually use a more robust attachment - to a weaker frame rail? I think the Taco is better suited for towing due to the rear suspension, but I'm not sure the 4runner can't be fixed with some air bags.

More importantly I suppose; isn't the hitch exactly the same as a GX460? It has a tow rating of 6500lbs - which would indicate that it's really somewhere into the class 4 range by SAE standards, but limited by a mfg recommended tow weight?

The GX460 hitch is different, it bolts to the rear cross member and the frame rails. There was someone on this forum that installed one on a 4runner for his concern of using a WD hitch. The Taco hitch is similar in that it bolts to the frame rails in front of the rear cross member.

 

[dieck]

A little more data

I've been watching the tranny temps the last couple of months and I thought I would share what I've observed.

The first pic is an example of daily driving without a trailer in Austin. On this day it was 85deg and the tranny stayed cool despite a couple hours of driving all over the city in stop and go traffic. Unloaded the tranny stays cool and it's hard to get it over 170 in the pan.

The second pic is an example of a road trip with my ~3000lb trailer also around 85 deg ambient. When the tranny is locked by putting the tranny in 5 or 4 the temp stays pretty reasonable. But the problem is the tranny is constantly unlocking itself (even when you have it in 5th gear with the shifter) and when it does the temps quickly climb. The high and low indicators show the range on this trip (about 600 miles) and in actual practice the tranny temps stayed in the 190/200 range. However, this was because I was actively managing the transmission manually. In the past if I've just left it in D the pan temps will get up into the 220+ range especially in the hills. I don't have a screen cap of this as I don't want to do it to the truck.

Other observations. When in 4L pulling the trailer at low speeds, the tranny has no issue keeping temps down. When at highways speeds and the tranny is locked in 5 or 4, it has no problem. But at moderate speeds 30-50 in hills the temps skyrocket because the tranny stays unlocked regardless of what you do. I was really surprised by how fast the temps spiked.

My conclusions: When towing keep it in 4th gear or proactively downshift from 5 to 4 before a hill. In slow speed winding mountain roads, watch your temps if towing.

Hope this is helpful.

I'm installing a transmission cooloer next week while I have the front bumper pulled for another project. Will be interested to see what effect it has on the temps when the trans is unlocked.

 

[flyrv9]

Filling tires with Nitrogen came from the aircraft industry. It's done because Nitrogen doesn't support combustion like Oxygen does; not so much because it's more pressure stable. The last thing you want is gear up in the well with a hot brake stack with a tire (filled with 160 psi of air) ready to blow and support a fire.

For cars it's more of a cool factor than a function factor. Race cars might see some benefit but you are better off saving your $ for mods!

Same with messages to the driver / pilot. Lots of info / status messages that used to be provided by gauges or messages are no longer relayed to the user; because they could be misinterpreted as problems and the fact that the last thing they would do is read the manual! That info, however, is stored and available by maint/engineering.

 

[dieck]

Agree on the nitrogen in tires.

But I wish we didn't just get dummy gauges.

Filling tires with Nitrogen came from the aircraft industry. It's done because Nitrogen doesn't support combustion like Oxygen does; not so much because it's more pressure stable. The last thing you want is gear up in the well with a hot brake stack with a tire (filled with 160 psi of air) ready to blow and support a fire.

For cars it's more of a cool factor than a function factor. Race cars might see some benefit but you are better off saving your $ for mods!

Same with messages to the driver / pilot. Lots of info / status messages that used to be provided by gauges or messages are no longer relayed to the user; because they could be misinterpreted as problems and the fact that the last thing they would do is read the manual! That info, however, is stored and available by maint/engineering.

 

[catrains]

my experience with nitrogen gas in the tires is stability of tire pressures as well as the alloy rims appear to have less corrosion inside the rim.

synthetic tranny fluids now used in most all vehicles now manufactured can take greater heat . adding a huge external tranny cooler will cause HVAC heat to be poor in the cold weather I had to remove the cooler in winter because of that effect.

towing up hills and you see the tranny temps rise above 210 F just slow down and put in a lower gear until the grade is gone saves the engine and tranny .

there are tranny cooler temp controlled systems so that when you need max fluid cooling it is then flowing thru the external cooler .. temp drops down to normal no external cooler flow ...many use this on towing with bigger more powerful trucks.

 

[dieck]

That's interesting about the HVAC heat in the winter. But I don't think I'll have the same issue in the south (I'm in Texas).

In my experience i'm trying to feather the throttle to keep the tranny from unlocking. The truck is happiest between 60 and 70 mph depending on the grade. Go much below 60 and it doesn't have enough RPM power to stay in 5th. If I run it in 4th all the time the RPM's stay too high. I like to tow around 65 ish. Sometimes on the long hauls in texas though it's unerving to have 18 wheelers passing you at 75/80 and in the metro areas it can create unsafe driving situations.

The cooler I got doesn't kick on until the temps are over 170 so it shouldn't over cool the engine coolant. We will see shortly.

my experience with nitrogen gas in the tires is stability of tire pressures as well as the alloy rims appear to have less corrosion inside the rim.

synthetic tranny fluids now used in most all vehicles now manufactured can take greater heat . adding a huge external tranny cooler will cause HVAC heat to be poor in the cold weather I had to remove the cooler in winter because of that effect.

towing up hills and you see the tranny temps rise above 210 F just slow down and put in a lower gear until the grade is gone saves the engine and tranny .

there are tranny cooler temp controlled systems so that when you need max fluid cooling it is then flowing thru the external cooler .. temp drops down to normal no external cooler flow ...many use this on towing with bigger more powerful trucks.

 

[catrains]

since you have the tranny cooler temp controlled type in cold weather you will not have any heat problems or also the engine not getting up to the designed operating temp which is very important. engine too cold is not good for various reasons.

some of these tranny coolers are adjustable I would set it @190 F. up to 210F is safe zone .

I tow @65MPH max and use the next lower gear. 4KLBS boat..mostly level ground. I do have a cooler but not the huge one .
my 1984 I had the huge sized one it did cool everything down ..too much though.

I also have to say you do not want to operate with the tranny shifting all the time towing , that is not good .
sounds like your trying to prevent the tranny from setting the OD lock up to engage ..

 

[meltdown]

[MENTION=124409]dieck[/MENTION] - Do you mind sharing the PID information you are using to get Transmission Temps? I'm using OBDFusion, but I don't think the numbers I'm seeing are accurate. When I checked it the other morning, ambient temp was 80, yet it was reading 113 even before starting the 4Runner. I'm using a PID I found here on t4r.org. Thanks.

 

[dieck]

[MENTION=124409]dieck[/MENTION] - Do you mind sharing the PID information you are using to get Transmission Temps? I'm using OBDFusion, but I don't think the numbers I'm seeing are accurate. When I checked it the other morning, ambient temp was 80, yet it was reading 113 even before starting the 4Runner. I'm using a PID I found here on t4r.org. Thanks.

Obd mode 21
PID 82

Converter
((((C * 256) + D ) * (7/100)-400)/10)

Pan
((((A * 256) + B ) * (7/100)-400)/10)

Hope that helps!

 

[dieck]

Also, to wrap up the whole transmission cooler install observations.

1. Recommend confirming the direction of transmission fluid flow by unplugging one of the hoses and seeing which way transmission fluid actually comes out. Its messy but difficult to mess up. I found conflicting information about the direction of flow in the stock radiator cooler and hoses.

Everything else went smoothly with the install.

2. The transmission runs significantly cooler than before. When not towing, the pan runs about 145, and when towing it runs about 170. I'm talking about long haul towing for several hours when the fluid is fully heat soaked, not around town. This is in the south (Texas) in high humidity and temps 95+.

3. Even when not towing the engine coolant temp gets to its standard temp quickly within about 1 min slower than before the cooler install, and engine temp stays pretty rock solid both around town and on long hauls both with and without the trailer.

4. No more big spikes in trans fluid temp on uphill grades or when pulling the trailer in rolling hills at 35-45 like before. The highest I've seen the pan get is 185 on an extended uphill pull with the trailer.

5. No differences in shifting that I can tell around town when not towing and the trans fluid is around 145ish.

I'm feeling pretty solid about this install for 4-Runners in the south that regularly tow long distances moderate to heavy trailers.

 

[meltdown]

Obd mode 21

PID 82



Converter

((((C * 256) + D ) * (7/100)-400)/10)



Pan

((((A * 256) + B ) * (7/100)-400)/10)



Hope that helps!

Thanks. That helps a little. That's the formula I have, but it looks like I'm having an issue with the metric to English conversion. I'll have to do some more research.

 

[dieck]

Thanks. That helps a little. That's the formula I have, but it looks like I'm having an issue with the metric to English conversion. I'll have to do some more research.

I had a little trouble with that too. In my app there is a separate location where you set F or C and then you cal also adjust it by calculation in the custom PID. Initially I was doing both and had a similar issue.

 

[meltdown]

Thanks [MENTION=124409]dieck[/MENTION]. I had some free time at work and tried some different things. I ended up having to figure the conversion in my formula. No matter how I had my settings, it always displayed something wrong. I'll play with it more when I get a chance, but it seems to be reading correctly for now.

 

[WallyT4R]

I am one that will try anything if I have detailed instructions. I have searched more than a few times and I must be doing something wrong because I can't find anything. There has to be a detailed write up or four on how to install a trans cooler on the 5th gen somewhere in this forum. Part numbers, hose routing, how to refill sealed trans, cooler mounts, etc...any help is appreciated..Thanks!

 

[dieck]

I am one that will try anything if I have detailed instructions. I have searched more than a few times and I must be doing something wrong because I can't find anything. There has to be a detailed write up or four on how to install a trans cooler on the 5th gen somewhere in this forum. Part numbers, hose routing, how to refill sealed trans, cooler mounts, etc...any help is appreciated..Thanks!

After monitoring my trans temps for more than a year my advice is.... if you tow with a 4r get one, if you dont tow, trany temp isnt an issue.

I found pretty comprehensive instructions and a video on etrailer although they had the inlet outlet hoses reversed. Install is really simple. Took an hour max

Any hayden or B&M cooler will be fine. I have a medium capacity cooler and i could have installed a smaller one and been ok. The design is simple. No real advantage to anything fancy..

 

[WallyT4R]

After monitoring my trans temps for more than a year my advice is.... if you tow with a 4r get one, if you dont tow, trany temp isnt an issue.

I found pretty comprehensive instructions and a video on etrailer although they had the inlet outlet hoses reversed. Install is really simple. Took an hour max

Any hayden or B&M cooler will be fine. I have a medium capacity cooler and i could have installed a smaller one and been ok. The design is simple. No real advantage to anything fancy..

Thanks for the reply, I will check out etrailer. The hose routing is the most important and I have never had a sealed transmission. I have put a trans cooler on a Tacoma before but there was a detailed write up with pics that I followed. Takes the guess work and potential problems out of the equation. Anyway thanks for helping me.