Trans overheated!

As far as I know , the oxidization tests that were performed used 1 hour of heat time for their study . The source of the study came from Empire Lubricants
Transmission coolers are an inexpensive fix to a serious problem . As others have mentioned , consider a larger after cooler in place of the tiny factory cooler
With this said , are you continuously monitoring your fluid temp with a gauge ?
If you hit 215 for half a minute , the fluid life would depend on how many times your transmission reached that temperature and for how long .
It would be far too difficult for you to add up the times and duration your transmission operated at 215 degrees .
For you guys who live in colder climates , your engine needs to warm the transmission up and this is where a quality cooler comes into play because a quality transmission cooler has a thermostat . Fluid bypasses the after cooler until the transmission reaches 180 degrees

 

I do have a scan guage to monitor temps.

 

Just trying to feel out upgrading my cooler or if more maintenance is necessary

 

I am new to towing with automatic transmissions so I was wondering if I could get a few questions answered from gearcruncher about after market tranny coolers. I have looked at all of the installs in these TW treads I can find and I like the

$185 Derale 52506 25 Row Core Stacked Plate Cooler Kit , Black

Derale 52506 for it's size and cooling capacity. While looking at the B&M 70264 they had a note about Low Pressure Drop (LPD) bypass which prevents the fluid from running thru the cooler until it heats up to a certain temp. Is the 52506 specified as a tranny cooler or is it a general purpose cooler and does it have the LPD bypass too? When these larger coolers are installed do they tell you how much additional tranny fluid to add or do we add by trial and error? Do these coolers keep the fluid in them when the truck is shut off or does it drain back into the tranny pan. If it drains back into the pan is the system overfilled until the LPD opens to allow it to flow thru the cooler? Will the tranny run too cool in the winter time? Any help would be greatly appreciated. Thanks in advance.

 

Lets have a peek at what transmission coolers do
TRANSMISSION COOLERS
If you do not have a transmission cooler on your truck and you plan to tow or haul heavy loads or you are in heavy stop and go traffic and use 4X4 low a lot , consider purchasing a cooler . The cooler thats built into your rad is designed to cool the transmission with the weight of just the truck by itself .When you are in 4x4 low , your torque converter is usually in the stall stage and creates a tonne of additional heat .You dont have much air flow going through your rad when you are in low range 4x4 .
160 - 200 are considered normal temps providing your engine radiator is functioning properly . If your engine overheats , your transmission will also overheat
Normal fluid temperature in transmission to be 175 deg. F.

Rate of oxidation to double for each temperature increase of 20 deg F above normal (175 deg F). As oxidation rate doubles, useful life of fluid is cut in half.

At 175 deg F life is 100,000 miles
At 195 deg F (20 deg above 175) life is 50k miles
At 215 life is 25k miles
At 235 life is 12k
At 255 life is 6,250
At 275 life is 3,000
At 295 life is 1500
At 315 life is 750

At temperatures much above 300 deg F the metals in the transmission will tend to warp, twist etc. high temperatures causes the formation of varnish deposits which impair or pre vent transmission operation.

At a fluid temperature of 415 deg F fluid life is 30 minutes!

Source: Empire Lubricants Inc.
Consider a scan guage http://www.amazon.com/ScanGauge-Comp.../dp/B000AAMY86
Here is the best information for the scan guage http://www.tacomaworld.com/forum/2nd...-pressure.html

Ultraguage is now offering transmission temps http://www.tacomaworld.com/forum/2nd-gen-tacomas/318340-ultragauge-transmission-temp.html

You could also use the Torque app with an Android phone as a cheap alternative to watch your temps http://www.tacomaworld.com/forum/per...d2-reader.html


A picture heavy write up showing a manual gauge install
https://www.tacomaworld.com/threads/trans-temp-sensor.456998/#post-13594000

$84 B&M 80212 Transmission Temperature Gauge Kit

https://www.amazon.ca/80212-Transmission-Temperature-Gauge-Kit/dp/B0002A596I


This is how Low Pressure Drop technology works::
When Automatic Transmission Fluid (ATF) is cold it is viscous. The unique Tru-Cool design allows the colder, thicker ATF to flow more efficiently through two open bypass channels positioned at the top of the cooler. As operating temperatures increase, the ATF becomes hotter and thinner, It's then directed through the core where it is cooled. Tru-Cool's highly efficient cooling technology combines improved protection against lube failure with optimal heat transfer.
http://www.amazon.com/Long-Tru-Cool-.../dp/B005XZXB1M
Long Tru-Cool Oil Coolers offer advanced cooling protection for many towing applications. The advanced technology out performs TUBE & FIN Designs, Delivers up to 15 times less flow restrictions, 30% more cooling delivers maximum heat transfer, Self-Regulating for maximum lube flow protection through start-up, varied temperatures and driving conditions, heavy loads and towing.
Here is Toyotas fluid flow guide ...Look at page 8 on this PDF http://www.toyotatundraforum.com/pdf/A750E.pdf
And here is a guy who recently installed a cooler correctly http://www.tacomaworld.com/forum/1st...agram-pic.html

cooler and fan install http://www.tacomaworld.com/forum/2nd...n-install.html

HERE is the Tacoma World Towing Bible https://www.tacomaworld.com/threads/the-tacoma-towing-bible.4031/


Here is a write up I put together for your 5 speed automatic
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

Source? As far as I know all 2nd gen V6's came with 3.73's

 

I've add a trans cooler and by passed the radiator to avoid adding heat.
Switched to amsoil full synthetic.
Doesn't get hot any more.

 

Gearcruncher, Thanks for the quick reply and all of the info. I read some of those threads starting with "The Towing Bible" prior to asking my questions. I eagerly read most of the threads you put in your answer as I felt they applied to me. You helped me decide on buying a Long Tru-Cool LPD 4590 cooler instead of the Derale. The 4590 is 11x11. I still have a lingering question about the amount of ATF that will flow thru it. If that cooler is full will it take too much out of the tranny pan and cause it to slip or something. I don't know if I am being overly careful or not. I will be doing a lot of towing in a year or so when I retire and want to set up the truck right prior to doing so. Thanks again for your help.

 

Install the cooler , re-fill the transmission . Take the truck for a good hot drive and then re-check the fluid level . This will guarantee all additional hosing as well as all cooling fins in the aftermarket cooler have been filled . The transmission fluid running through the transmission cooling system is a loop that goes back to the transmission pan once the fluid has been cooled

 

What temps are you seeing now?

 

I need to get a meter but I have a good guess.

The truck runs at 185 and the stock trans cooler would get way hotter than the radiator, so well over 200 degrees.
And now it never gets hotter than the radiator, I guess 150-175 max..

I think under normal cruising around 150 which is a little cool but drives fine.
On the dunes it never gets hotter than the radiator.

Just do some towing or off roading open the hood and see how hot it gets, it is crazy hot hot it gets.

One year at the dunes I burnt the trans fluid, that's when I changed to amsoil and added the cooler.
After a few years with the cooler I did a 3 qt change and the fluid looked like new.

 

You should look at the ultragauge mx. That's what I have, I love it. I have it reading pan and TC temps. I still have WS in mine, running between 100° and 150° With ambient temps around 75°. Highest I've seen is 200° at the TC towing heavy.

 

And it has trans temps? I have to ck it out. That would be nice for checking fluid levels.

Yeah it's hard to know the exact temps but it's way cooler, I can hold the trans cooler after running the dunes and before it would burn your hand just to touch it. I guessing by comparing to the engine temp and I know that is 185.

 

Check out post #46 from gearcruncher, there's a link to the ultragauge thread.
It's worth noting that I have a remote filter mount and spin on filter plumbed in in front of the condenser, so my temps are probably running a slightly cooler than other people's.

 

Yeah your engine temp is 10 degrees cooler.

 

It wasn't up to operating temp when I took that pic, I had just got back from a road trip, I turned my truck off and let it sit for a few minutes... then came back and started it a few minutes later to take that pic for TW. My remote filter mount and filter are for the tranny btw.

 

Ok I have some more accurate numbers.. Just bought a cheap infrared thermometer. Works good, only 30 bucks..

So I know my engine runs at 185.
Radiator cap was 150 degrees.
Trans radiator 80 degrees.

So at 45 degrees my trans runs about 110-115 degrees...

I still think it stays about a max of 165 under heavy use, but now I can ck it this year.

 

The ultragauge mx is only $90. Watch for a group buy, sometimes you can get them pretty cheap. Or you can get a obd dongle and use an app to monitor temps if you have an old smartphone you can repurpose.

 

@shr133 also note that the aux trans cooler is after radiator cooler, so isn't an accurate representation of the outlet temp of the fluid from the transmission.