Transmission Temperature Spikes - Page 2 - Toyota 4Runner Forum

gamefreakgc · 08-12-2019, 06:30 PM

Swap out for a bigger cooler. Bigger is always better unless you live a in a climate with brutally cold winters (may not reach optimum running temp).

The Tru Cool 4490 is bigger with a BTU rating of 22,000 and has a cold bypass system to help fluid warm up quicker on cold starts. The B&M 70264 transmission cooler only has a BTU rating of 14,400, that's an increase of over 50% more cooling capacity. Your overheating issues will be over.

And use 4LO when you can.

Cree · 08-12-2019, 07:53 PM

Quote:

Originally Posted by gamefreakgc

Swap out for a bigger cooler. Bigger is always better unless you live a in a climate with brutally cold winters (may not reach optimum running temp).

The Tru Cool 4490 is bigger with a BTU rating8 of 22,000 and has a cold bypass system to help fluid warm up quicker on cold starts. The B&M 70264 transmission cooler only has a BTU rating of 14,400, that's an increase of over 50% more cooling capacity. Your overheating issues will be over.

And use 4LO when you can.

Bro I'm not sure what you're looking at and maybe I'm just looking at something different. But from what I can see the B&M is actually rated for more Towing than the TRU cool is. I do not see a BTU rating for the TRU cool just a tow rating of 22,000 lb, whereas the B&M is 14000 BTU rated for 24,000 lb. Just for conversation's sake the Hayden 679 but I'm running is rated for 30,000, although I cannot find a BTU rating for it anywhere.

gamefreakgc · 08-12-2019, 10:01 PM

Quote:

Originally Posted by Cree

Bro I'm not sure what you're looking at and maybe I'm just looking at something different. But from what I can see the B&M is actually rated for more Towing than the TRU cool is. I do not see a BTU rating for the TRU cool just a tow rating of 22,000 lb, whereas the B&M is 14000 BTU rated for 24,000 lb. Just for conversation's sake the Hayden 679 but I'm running is rated for 30,000, although I cannot find a BTU rating for it anywhere.

Sorry for the typo. It's rated at 20,000 BTU's so it has a 39% larger cooling capacity than the B&M 70264's 14,400. The OP will notice cooler temperatures for longer if he switches them out.

The dimensions for the Hayden is almost identical to the Tru Cool 4490's so it is probably also rated at 20,000 BTU's. Interesting that Hayden doesn't post the BTU ratings though, they must not be that much different or they would have them more visible.

Cree · 08-12-2019, 10:23 PM

Quote:

Originally Posted by gamefreakgc

Sorry for the typo. It's rated at 20,000 BTU's so it has a 39% larger cooling capacity than the B&M 70264's 14,400. The OP will notice cooler temperatures for longer if he switches them out.

The dimensions for the Hayden is almost identical to the Tru Cool 4490's so it is probably also rated at 20,000 BTU's. Interesting that Hayden doesn't post the BTU ratings though, they must not be that much different or they would have them more visible.

Interesting. Well, all I know is I'm happy with it. Im getting set up for boost so trying to figure out all the supporting stuff first. I haven't towed yet but now I'm tempted to see what it does.

OP, keep us in the loop. Curious to see what your solution is.

4runnerfiend · 08-13-2019, 10:31 AM

I installed a Hayden 679 bypass. only time i saw it get close to 200 was when I was wheeling slow steep grade in 4 high. Normally I would be in 4 lo for that. I wanted to see How it handled it. even when it got that high it quickly came down to 170-180 ish.

mtbtim · 08-13-2019, 11:26 AM

Quote:

Originally Posted by 4runnerfiend

I installed a Hayden 679 bypass. only time i saw it get close to 200 was when I was wheeling slow steep grade in 4 high. Normally I would be in 4 lo for that. I wanted to see How it handled it. even when it got that high it quickly came down to 170-180 ish.

With that big cooler and bypassing the radiator cooler, what kind of temps are you running in colder weather? Now, I know San Diego doesn't get all that cold but I'm curious what kind of numbers you're seeing in the winter. I know these coolers have a thermal bypass which lets the thicker cold fluid run straight through the cooler and back to the transmission until the fluid warms up and thins out to run through the cooling channels of the cooler. But, I wonder how effective the thermal bypass is.

Running a cooler in-series helps in colder weather bring the fluid to an optimum temp because the radiator trans cooler is bathed in the radiator coolant which is at 180-190 degrees. ATF has an optimum operating temp around 170 degrees. It actually isn't good to run way under the optimum temp range all the time. The reason why you feel hard shifts when the trans is cold is because the fluid is thick and not lubricating as well as it would when it's at operating temps. Also, low consistent temps in the trans can allow moisture to accumulate in the trans which isn't good.

Even with my smaller B&M 70264 cooler ran in-series with the radiator cooler, I quite often see relatively low temps, 130s-140s doing mellow around town driving. It's not until I get on the highway for a longer trip or drive in the mountains that I see my trans temp get into a more optimum temp range. So, I'm really curious what temps you're running with your set-up. If you've driven your rig to the mountains with snow on the ground, what kind of temps have you seen then? I'd like to hear from @Cree too since he's running the same set-up.

4runnerfiend · 08-13-2019, 12:01 PM

Quote:

Originally Posted by mtbtim

With that big cooler and bypassing the radiator cooler, what kind of temps are you running in colder weather? Now, I know San Diego doesn't get all that cold but I'm curious what kind of numbers you're seeing in the winter. I know these coolers have a thermal bypass which lets the thicker cold fluid run straight through the cooler and back to the transmission until the fluid warms up and thins out to run through the cooling channels of the cooler. But, I wonder how effective the thermal bypass is.

Running a cooler in-series helps in colder weather bring the fluid to an optimum temp because the radiator trans cooler is bathed in the radiator coolant which is at 180-190 degrees. ATF has an optimum operating temp around 170 degrees. It actually isn't good to run way under the optimum temp range all the time. The reason why you feel hard shifts when the trans is cold is because the fluid is thick and not lubricating as well as it would when it's at operating temps. Also, low consistent temps in the trans can allow moisture to accumulate in the trans which isn't good.

Even with my smaller B&M 70264 cooler ran in-series with the radiator cooler, I quite often see relatively low temps, 130s-140s doing mellow around town driving. It's not until I get on the highway for a longer trip or drive in the mountains that I see my trans temp get into a more optimum temp range. So, I'm really curious what temps you're running with your set-up. If you've driven your rig to the mountains with snow on the ground, what kind of temps have you seen then? I'd like to hear from @Cree too since he's running the same set-up.

I have not been up to colder climates with it yet, or the snow.

Initially when I installed it I ran it in series, did a ton of research on it and thought it was the better way to go.
After install I had the truck into a shop for major engine work (Toytoa specialist), the ran it in bypass when putting the engine back together. Said it was leaking from the fitting. I asked about it running too cold and they said we don't live in a cold enough climate to worry about it.

All the points you bring up make alot of sense. I agree and have the same temps.. quick around town it really doesn't warm up 130-140 ish. even with freeway driving/non demanding it will be 150-165.
I don't have hard shifts, actually way better than before the cooler.

Really I only go to the mountains/snow 1 time a year if I'm lucky. that may change in the future as my kids get older.

you think having thicker/colder fluid will effect MPG?

4runnerfiend · 08-13-2019, 12:15 PM

Quote:

Originally Posted by mtbtim

With that big cooler and bypassing the radiator cooler, what kind of temps are you running in colder weather? Now, I know San Diego doesn't get all that cold but I'm curious what kind of numbers you're seeing in the winter. I know these coolers have a thermal bypass which lets the thicker cold fluid run straight through the cooler and back to the transmission until the fluid warms up and thins out to run through the cooling channels of the cooler. But, I wonder how effective the thermal bypass is.

Running a cooler in-series helps in colder weather bring the fluid to an optimum temp because the radiator trans cooler is bathed in the radiator coolant which is at 180-190 degrees. ATF has an optimum operating temp around 170 degrees. It actually isn't good to run way under the optimum temp range all the time. The reason why you feel hard shifts when the trans is cold is because the fluid is thick and not lubricating as well as it would when it's at operating temps. Also, low consistent temps in the trans can allow moisture to accumulate in the trans which isn't good.

Even with my smaller B&M 70264 cooler ran in-series with the radiator cooler, I quite often see relatively low temps, 130s-140s doing mellow around town driving. It's not until I get on the highway for a longer trip or drive in the mountains that I see my trans temp get into a more optimum temp range. So, I'm really curious what temps you're running with your set-up. If you've driven your rig to the mountains with snow on the ground, what kind of temps have you seen then? I'd like to hear from @Cree too since he's running the same set-up.

I wonder if Toyota has published Min and Max operating temps for the Transmission.

I was reading up on a Jeep forum and for the JK they are saying the min operating temp is 80.
Obviously each vehicle is different. and Toyota wants it higher than that if it comes from the factory connected to the radiator.

phattyduck · 08-13-2019, 12:45 PM

Quote:

Originally Posted by 4runnerfiend

I wonder if Toyota has published Min and Max operating temps for the Transmission.

They may, but easily accessed information says this (checking trans fluid level in the FSM):

Code:

10. AUTOMATIC TRANSMISSION FLUID LEVEL
(a) Park the vehicle on a level surface.
(b) With the engine idling and the parking brake applied, shift the selector
into all positions from ”P” to ”L”, and then shift into ”P” position.
(c) Pull out the dipstick and wipe off the fluid with a clean rag. 
Re−insert the dipstick and check that the fluid level is in the HOT range.
(d) Do this check with the fluid at normal driving temperature (70−80°C, 158−176°F).

HINT:
Wait until the engine cools down (approx. 30 min.) before 
checking the fluid level after extended driving at high speeds, 
in hot weather, in heavy traffic or pulling a trailer.

So, normal (I'd read that as 'ideal') operating temperatures are 70-80*C / 158-176*F.

Also of note - the coolant temperatures at the bottom of the radiator should be well below normal operating temps of the engine. I'd guess generally ~20*F or more cooler than the engine. Otherwise, the thermostat wouldn't have any 'cool' water to use to cool the engine - and the thermostat generally isn't open all the way.

-Charlie

mtbtim · 08-13-2019, 12:45 PM

Quote:

Originally Posted by 4runnerfiend

I have not been up to colder climates with it yet, or the snow.

Initially when I installed it I ran it in series, did a ton of research on it and thought it was the better way to go.
After install I had the truck into a shop for major engine work (Toytoa specialist), the ran it in bypass when putting the engine back together. Said it was leaking from the fitting. I asked about it running too cold and they said we don't live in a cold enough climate to worry about it.

All the points you bring up make alot of sense. I agree and have the same temps.. quick around town it really doesn't warm up 130-140 ish. even with freeway driving/non demanding it will be 150-165.
I don't have hard shifts, actually way better than before the cooler.

Really I only go to the mountains/snow 1 time a year if I'm lucky. that may change in the future as my kids get older.

you think having thicker/colder fluid will effect MPG?

Would thicker fluid affect gas mileage? Maybe I guess. I'm not so much worried about gas mileage as much as having the trans fluid at an ideal temp to properly lubricate the trans.

nevada · 08-13-2019, 12:48 PM

Quote:

Originally Posted by Toy2play

Yeah I know it's off for sure. When towing it very easy to tell if its on or off. Tranny temps go up fast if OD is on, dash light is showing. RPM's are high, 3000-3500 and sometimes past 4000 when I'm struggling on the really steep inclines. This is even with my supercharger. I hate how much I have to push the engine to maintain any respectable speed on the roads when towing. I've started to look at 4th gen 4.7 V8, but I can't bring myself to buying another vehicle for the soul purpose of towing. I can't bare to get rid of my 3rd gen since I've dumped so much money into it. Other than the slow crawling high tranny temps and crappy towing, I love this runner.

if you're going to be towing that weight consistently, get the v8 4runner. save your 3rd gen for playing.

just for reference sake, this is the cooler I ended up putting on my v8 truck. its HUGE, but keeps the trans cool in all conditions. its rated at 45,000 BTU's, and 40,000 GVW. I installed mine with the thermal bypass, since I use the truck quite often for snow wheeling. could be an upgrade for you, if you insist on making the 3rd gen work for towing...

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

Cree · 08-13-2019, 01:05 PM

Quote:

Originally Posted by mtbtim

With that big cooler and bypassing the radiator cooler, what kind of temps are you running in colder weather? Now, I know San Diego doesn't get all that cold but I'm curious what kind of numbers you're seeing in the winter. I know these coolers have a thermal bypass which lets the thicker cold fluid run straight through the cooler and back to the transmission until the fluid warms up and thins out to run through the cooling channels of the cooler. But, I wonder how effective the thermal bypass is.

Running a cooler in-series helps in colder weather bring the fluid to an optimum temp because the radiator trans cooler is bathed in the radiator coolant which is at 180-190 degrees. ATF has an optimum operating temp around 170 degrees. It actually isn't good to run way under the optimum temp range all the time. The reason why you feel hard shifts when the trans is cold is because the fluid is thick and not lubricating as well as it would when it's at operating temps. Also, low consistent temps in the trans can allow moisture to accumulate in the trans which isn't good.

Even with my smaller B&M 70264 cooler ran in-series with the radiator cooler, I quite often see relatively low temps, 130s-140s doing mellow around town driving. It's not until I get on the highway for a longer trip or drive in the mountains that I see my trans temp get into a more optimum temp range. So, I'm really curious what temps you're running with your set-up. If you've driven your rig to the mountains with snow on the ground, what kind of temps have you seen then? I'd like to hear from @Cree too since he's running the same set-up.

I don't have that data yet. We've had a few 60 degree mornings since install. It popped up to 120/130 fairly quick and topped out around 140 on my 10 mile drive to work. 2 stop lights, no hills.

Im going to bet that I'll have to do the old cardboard trick in the winter here. BUT. I would much rather do that then have it hot. I've thought about making a bypass back to the radiator for the winter time, but more likely is if it's that big of a problem I'll swap to the 699 since it's internally bypassed. Had I known Id see the drops I did I might've done that from the start.

I also think it drives and shifts better than before the install.

Toy2play · 08-13-2019, 06:47 PM

Quote:

Originally Posted by gamefreakgc

Swap out for a bigger cooler. Bigger is always better unless you live a in a climate with brutally cold winters (may not reach optimum running temp).

The Tru Cool 4490 is bigger with a BTU rating of 22,000 and has a cold bypass system to help fluid warm up quicker on cold starts. The B&M 70264 transmission cooler only has a BTU rating of 14,400, that's an increase of over 50% more cooling capacity. Your overheating issues will be over.

And use 4LO when you can.

Yeah that's what I'm thinking, go up in size or get another one that will double my capacity.

Quote:

Originally Posted by nevada

if you're going to be towing that weight consistently, get the v8 4runner. save your 3rd gen for playing.

just for reference sake, this is the cooler I ended up putting on my v8 truck. its HUGE, but keeps the trans cool in all conditions. its rated at 45,000 BTU's, and 40,000 GVW. I installed mine with the thermal bypass, since I use the truck quite often for snow wheeling. could be an upgrade for you, if you insist on making the 3rd gen work for towing...

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

I'm seriously considering the 4.7 4th gen and keeping it basically bone stock. I dont think my 3rd gen will ever tow comfortably. I never really intended to tow anything with it so I set it up for more of an overland vehicle. The pop-up trailer is great to have for trips that the fam doesn't venture too far from the pavement. In the mean time, maybe I'll make a few adjustments to see if I can get my temperatures down a bit.

Thanks for the link, I'm thinking regardless I need to go up in size or get another one like I have already.

gamefreakgc · 08-13-2019, 07:03 PM

Quote:

Originally Posted by mtbtim

Would thicker fluid affect gas mileage? Maybe I guess. I'm not so much worried about gas mileage as much as having the trans fluid at an ideal temp to properly lubricate the trans.

I can answer the opposite question, does any thinner fluid increase gas mileage on a 4Runner? The definitive answer to that is no, been there done that. I can't imagine thicker would affect it much the other direction, if at all.

I honestly think that 3rd Gen's just were not made to tow anything of significant weight. Yeah, it has a tow rating of up to 5,000 lbs depending on the year and engine size but with a narrow wheelbase and only weighing 3950 dry (Toyota's published number anyway) it's just not that great at it. A V8 4Runner not only have more power but also more weight which makes a difference when towing but even that can't compare to a Tundra of similar year or something entirely different like an F-150. If you find yourself towing more than a utility trailer on a consistent basis, it might be time for a more dedicated vehicle that does it well.

Toy2play · 08-13-2019, 09:12 PM

Quote:

Originally Posted by gamefreakgc

I honestly think that 3rd Gen's just were not made to tow anything of significant weight. Yeah, it has a tow rating of up to 5,000 lbs depending on the year and engine size but with a narrow wheelbase and only weighing 3950 dry (Toyota's published number anyway) it's just not that great at it. A V8 4Runner not only have more power but also more weight which makes a difference when towing but even that can't compare to a Tundra of similar year or something entirely different like an F-150. If you find yourself towing more than a utility trailer on a consistent basis, it might be time for a more dedicated vehicle that does it well.

I'm looking at the 05-09 4.7 runners right now. I'm wondering how much the difference will be with my 3rd gen supercharged runner with 2.2 pulley vs the stock 4.7 v8? I know that my tires and extra weight certainly kill some power. I would hope there is a significant difference, especially if I kept the 4th gen completely stock. Like I said in the past, this popup loaded shouldn't be more than 3000-3300 pounds. Thankfully the popup has electric brakes and I'll installed a brake controller. Really helps with braking. The 3rd gen doesn't feel like it gets thrown around too much with this load, just lack of power on steeper inclines.

Maybe I'll install a bigger cooler for the 3rd gen and see if that helps with slow speed off roading in combination with using 4lo more.

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