Transmission Temperatures and How it Relates to Life of the Fluid

[mtbtim]

I just found some information on a website regarding transmission temperatures and how it relates to the life of the fluid. Normal driving will raise your temperatures to around 80 degrees celsius or 176 degree fahrenheit. At this temperature, the fluid could last you up to 100,000 miles. But, most transmissions will get hotter than this for various reasons (towing, driving up a steep 4x4 trail, etc.). For every 15 degree celsius above 80, the fluid's lifespan is cut in half. At 90 degrees celsius or 194 degrees fahrenheit, the fluid will last for 50,000 miles. At 110 celsius or 230 degrees fahrenheit which is commonly encountered in many transmissions, the fluid life is cut to 37,000 miles. I guess this is why it's suggested to change your ATF at 30,000 mile intervals. At 120 degree celsius or 250 degrees fahrenheit, the life of the fluid is cut to around 9300 miles.

The hottest I've seen my trans get is 232. That was from driving up a steep mountain road, carrying a bunch of gear and pulling a motorcycle trailer. I have since installed a B&M 70264 cooler in series with the radiator cooler and have seen a 20 degrees temperature drop. So, hopefully I won't be seeing anything much more than 210 in my rig now.

So, if you're regularly seeing temps above 230, you should either be doing something to get the temps down or changing your trans fluid much more often to extend the life of your transmission.

Here's the link to the website if you'd like to read more. I think you'll find it pretty interesting.
http://www.thetransmissioncentre.com.au/general-information/

 

[PCF4runner]

Thanks for sharing! [emoji1474]


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[PCF4runner]

I just found some information on a website regarding transmission temperatures and how it relates to the life of the fluid. Normal driving will raise your temperatures to around 80 degrees celsius or 176 degree fahrenheit. At this temperature, the fluid could last you up to 100,000 miles. But, most transmissions will get hotter than this for various reasons (towing, driving up a steep 4x4 trail, etc.). For every 15 degree celsius above 80, the fluid's lifespan is cut in half. At 90 degrees celsius or 194 degrees fahrenheit, the fluid will last for 50,000 miles. At 110 celsius or 230 degrees fahrenheit which is commonly encountered in many transmissions, the fluid life is cut to 37,000 miles. I guess this is why it's suggested to change your ATF at 30,000 mile intervals. At 120 degree celsius or 250 degrees fahrenheit, the life of the fluid is cut to around 9300 miles.

The hottest I've seen my trans get is 232. That was from driving up a steep mountain road, carrying a bunch of gear and pulling a motorcycle trailer. I have since installed a B&M 70264 cooler in series with the radiator cooler and have seen a 20 degrees temperature drop. So, hopefully I won't be seeing anything much more than 210 in my rig now.

So, if you're regularly seeing temps above 230, you should either be doing something to get the temps down or changing your trans fluid much more often to extend the life of your transmission.

Here's the link to the website if you'd like to read more. I think you'll find it pretty interesting.
http://www.thetransmissioncentre.com.au/general-information/

Does the same principle apply for synthetic fluid also?

 

[TXLX1]

So how many quarts are in a 4Runner? Are most people doing drain and fill or a "flush" when they trans fluid is changed?

I bought mine recently and the fluid is between red and brown. My plan is to drain and fill every 3k with an oil change until it's red and then drain and fill based on color.

 

[St Runner]

I feel that if you are pushing the high end of temperature (230) you should do a 12 quart DIY flush with a synthetic fluid. It will be much more tolerant of those higher temperatures.

 

[mtbtim]

I feel that if you are pushing the high end of temperature (230) you should do a 12 quart DIY flush with a synthetic fluid. It will be much more tolerant of those higher temperatures.

I believe anyone who uses their 3rd Gen for more than driving around town running errands and dropping their kids off for school is going to see higher temps. I drove up a steady 7 mile mountain road in my area and by the top I had reached 220 degrees and all I was carrying was myself and my girlfriend.

I'm not sure running synthetic is the answer for everyone. Using synthetic will allow your trans to run cooler but I've read there are pluses and minuses to switching over to synthetic. Since synthetic is a thinner fluid, you may see leaks in seals that weren't leaking beforehand. Also since it's thinner, your older trans might experience slipping. I'm not an expert on this subject by any means but I would recommend you do your own research before switching over to running synthetic in your trans.

 

[jgue467]

...
The hottest I've seen my trans get is 232. That was from driving up a steep mountain road, carrying a bunch of gear and pulling a motorcycle trailer. I have since installed a B&M 70264 cooler in series with the radiator cooler and have seen a 20 degrees temperature drop. So, hopefully I won't be seeing anything much more than 210 in my rig now.[/url]

When you get to these high temps are you using OD override? I use it many times when climbing hills or mountain passes, temps drop to well under 200 sometimes 180 when my ambient temps are at 105 here in central texas summers. Luck and enjoy! :cowboy:

 

[mtbtim]

So how many quarts are in a 4Runner? Are most people doing drain and fill or a "flush" when they trans fluid is changed?

I bought mine recently and the fluid is between red and brown. My plan is to drain and fill every 3k with an oil change until it's red and then drain and fill based on color.

I looked through my FSM and it doesn't tell me the total capacity, only how much you remove on a drain and refill which I found to be inaccurate. I have read on one thread that the total capacity is 12 quarts and on another 11 quarts.

What I do know is when I do a drain and refill, I remove apprx. 5 quarts. I've changed my ATF several times and this amount is very consistent.

I decided on a frequency of every 10,000 miles. Why? Well, here's my thinking. Since the recommended interval of renewing trans fluid is 30,000 miles unless you're doing a lot of towing and hard driving and then it's 15,000 miles, I figure over a 30,000 mile period, I will have removed and replaced 15 quarts which means I've renewed the total capacity of trans (actually more). Now, I know what I'm doing is a dilution process and not the same as a complete flush but this method is effective and easy for anyone to do.

Since a drain and refill is extremely easy, why not give your trans some fresh fluid at a more frequent interval to extend it's life. You could do the more involved DIY flush of the entire system, but why. If you give your trans fresh fluid on a regular basis by doing a drain and refill, you're keeping the fluid in good shape. But hey, it's your rig, so do what you think is best.

Bar none, doing regular fluid changes is the best way to extend the life of your vehicle's major components like the engine, trans, transfer case, and differentials.

 

[mtbtim]

When you get to these high temps are you using OD override? I use it many times when climbing hills or mountain passes, temps drop to well under 200 sometimes 180 when my ambient temps are at 105 here in central texas summers. Luck and enjoy! :cowboy:

I had OD off. The hill I reached this temp on is long and consistently steep and I was carrying a load. But, I reached 220 recently just driving up a 7 mile mountain road carrying no load other than one passenger. I think the temps are definitely affected by how much air flow you have. The higher temps I've seen are when driving around 30 mph. If you're driving over a mountain pass on the freeway, but you're able to maintain speeds of 50-60 mph, I would guess that the temps would be lower because you have more air moving across the radiator cooling fins.

I do wonder if the temps vary depending on the scan tool you're using. I'm using a bluetooth OBD II sensor that's sending info to my phone running the Torque Pro app. I wonder if I'd record the same temps running a Scan Gauge.

 

[St Runner]

Synthetic fluid won't make the transmission run cooler, it stays more stable and does not break down as much at higher temps. It will not solve the problem of running too hot, that needs to be fixed by more cooling. But it will extend the life of your transmission fluid if you occasionally run it on the high side. As far as more prone to leaking , I have heard the rumors but never personally seen it happen

 

[potomacduck]

I do a drain and fill ( about 4-5 quarts) each time I do an oil change, so every 10,000 miles.

I know it's not the same as a complete fluid change but the ATF is bright red and clean each time I change it.

.

 

[jstim]

I've had this crazy thought lately. We all want lower tranny temps, what if I added an additional B&M cooler? That way it's go from one cooler to the next then back to the trans?

Has anyone else heard of doing this?

 

[MountainBiker]

I've had this crazy thought lately. We all want lower tranny temps, what if I added an additional B&M cooler? That way it's go from one cooler to the next then back to the trans?

Has anyone else heard of doing this?

I'd just go with a larger cooler. Less fittings, less chance for sh&t to happen.

 

[T4R2014]

I change it every year now. These things are old and the fluid is cheap. There's some things the service schedule can't account for after 20 years.

 

[jgue467]

I've had this crazy thought lately. We all want lower tranny temps, what if I added an additional B&M cooler? That way it's go from one cooler to the next then back to the trans?

Has anyone else heard of doing this?

Or a fan for those lower speed/city stop n go situations? that is really the only situation where mine can climb a little over 200 and I have trouble controlling it cuz of the lack of sufficient air flow. Just a thought. :cowboy:

 

[mtbtim]

I've had this crazy thought lately. We all want lower tranny temps, what if I added an additional B&M cooler? That way it's go from one cooler to the next then back to the trans?

Has anyone else heard of doing this?

The thought actually crossed my mind as well to run dual coolers.

I chose to run my B&M 70264 cooler in series with the radiator cooler because I believe this setup keeps the trans fluid temps within the optimum range better than a stand-alone external cooler setup. From my own research, temps from 150-180 are the normal operating temps for our trans. The trans obviously runs cooler when you first start out driving, but it warms up fairly quickly aided by heat from the coolant surrounding the trans cooler in the radiator. You can have temp spikes when you are climbing hills/mountains, driving slow in traffic, 4wheeling up a steep trail, towing a load, etc.
[MENTION=78997]Drcoffee[/MENTION] stated that with his experience, a external trans cooler ran in-series with the radiator cooler will drop your temps around 20 degrees, which I found to be pretty accurate. It's not so much cooling that it's going to cause my trans to run too cool and it's going to help with me from running a little too hot.

When you run a stand-alone external cooler, you are going to be more prone to seeing very low temps and very high temps depending on the situation. If you're driving in sub-freezing temps, your trans is going to run cooler because it's lacking the benefit of the stock cooler in the radiator bringing up the temp from the heat of the coolant surrounding it. When you're pulling a load up a slow mountain road, 4wheeling up a steep trail going slow, you're not getting sufficient air flow over the fins of the cooler to bring the temps down effectively so your trans temp is going to spike. Now if you put the extra effort into putting electric fans over your cooler, you can combat the higher temps in those situations. But, what do you do about the colder climate situations. Maybe put some type of air dam in front of the grill? I don't know.

I realize running a cooler in-series doesn't prevent the possibility of the pink milkshake, but it's my belief this failure is pretty darn rare, and because we frequent forums like this one, we get a skewed view of how prevalent a certain problem is. For instance, I bought into the fear of the lower balljoint failure and replaced balljoints that were probably going to last me another 100,000 miles. The balljoint boots were completely intact, had plenty of grease still inside (I actually cut one of the boots off to see) and there was no detectable play that I could feel. I also replaced my radiator due to the fear of the pink milkshake. I've only replaced one radiator in my life before this and it was because it finally sprung a leak at almost 300,000 miles. But hey, maybe I'll sleep a little better knowing I have a new balljoints and a new radiator.

 

[amalik]

The thought actually crossed my mind as well to run dual coolers.

I chose to run my B&M 70264 cooler in series with the radiator cooler because I believe this setup keeps the trans fluid temps within the optimum range better than a stand-alone external cooler setup. From my own research, temps from 150-180 are the normal operating temps for our trans. The trans obviously runs cooler when you first start out driving, but it warms up fairly quickly aided by heat from the coolant surrounding the trans cooler in the radiator. You can have temp spikes when you are climbing hills/mountains, driving slow in traffic, 4wheeling up a steep trail, towing a load, etc.

[MENTION=78997]Drcoffee[/MENTION] stated that with his experience, a external trans cooler ran in-series with the radiator cooler will drop your temps around 20 degrees, which I found to be pretty accurate. It's not so much cooling that it's going to cause my trans to run too cool and it's going to help with me from running a little too hot.

When you run a stand-alone external cooler, you are going to be more prone to seeing very low temps and very high temps depending on the situation. If you're driving in sub-freezing temps, your trans is going to run cooler because it's lacking the benefit of the stock cooler in the radiator bringing up the temp from the heat of the coolant surrounding it. When you're pulling a load up a slow mountain road, 4wheeling up a steep trail going slow, you're not getting sufficient air flow over the fins of the cooler to bring the temps down effectively so your trans temp is going to spike. Now if you put the extra effort into putting electric fans over your cooler, you can combat the higher temps in those situations. But, what do you do about the colder climate situations. Maybe put some type of air dam in front of the grill? I don't know.

I realize running a cooler in-series doesn't prevent the possibility of the pink milkshake, but it's my belief this failure is pretty darn rare, and because we frequent forums like this one, we get a skewed view of how prevalent a certain problem is. For instance, I bought into the fear of the lower balljoint failure and replaced balljoints that were probably going to last me another 100,000 miles. The balljoint boots were completely intact, had plenty of grease still inside (I actually cut one of the boots off to see) and there was no detectable play that I could feel. I also replaced my radiator due to the fear of the pink milkshake. I've only replaced one radiator in my life before this and it was because it finally sprung a leak at almost 300,000 miles. But hey, maybe I'll sleep a little better knowing I have a new balljoints and a new radiator.

Don't beat yourself up too much about it... I also have a new radiator (and aux tranny cooler) and new ball joints as well, replaced at around 210k. Both jobs only because of the forum like you. I had the LBJ's checked for play at Meineke and there was 0 play according to the technician, still did them for peace of mind.

Although it may be overkill if they had no play, keep in mind on 2001/2002 3rd gen's, it is an official recall, so obviously something was wrong.

Do you plan to add an electric fan to your setup?

 

[mtbtim]

Don't beat yourself up too much about it... I also have a new radiator (and aux tranny cooler) and new ball joints as well, replaced at around 210k. Both jobs only because of the forum like you. I had the LBJ's checked for play at Meineke and there was 0 play according to the technician, still did them for peace of mind.

Although it may be overkill if they had no play, keep in mind on 2001/2002 3rd gen's, it is an official recall, so obviously something was wrong.

Do you plan to add an electric fan to your setup?

I was thinking about adding a fan. How involved is it to do? I'm electrically challenged so I'd have to learn how to do electrical without shorting out my rig and burning it up.

 

[BigFishAllDay]

I've had this crazy thought lately. We all want lower tranny temps, what if I added an additional B&M cooler? That way it's go from one cooler to the next then back to the trans?

Has anyone else heard of doing this?

That's how I'm set up. I can't break 180 degrees on my output (pre-cooler) temps if I try, and believe me I've tried. My normal running temps are 120-150 under all conditions, all seasons. I am bypassing the stock in-rad cooler. Fully armored, geared, supercharged, IPT valve body all that. I live and drive the rig in NM where summer temps are over 100, and in CO during the winter in temps as low as -30.

I (normally) don't participate in these threads (even my own write-up) because everyone thinks they have the best answer. Take it for what it's worth.

 

[BigFishAllDay]

BTW, if anyone thinks 120-150 degrees is too cool, try warming up some trans fluid in a pan on your stove to that temp, then pour it on your hand.

Come back and report your findings.