snap-on

For those of us that actually have real temp guages please post up.

Ive had a autometer trans temp on my 4runner for about a year now. most of which it sat on the side in the "driveway" while i was doing the rebuild on it.

(to the point)

Im running an aftermarket cooler upfront AFTER the radiator. My gauge is plumbed in the rubber hose leading FROM the trans BEFOR the radiator. (ie hotest temp)

my trans temp is ALLLLLL Over the gauge.... some days i dont break 210... others i can peg out the gauge at 250.... Ive seen the gauge jump from 180-210 in 3 min and vise versa....

for those that know the acutall temps, post your setup and some temps.

slosurfer

My temp guage is in the same place as yours and I have an aftermarket cooler in front of the radiator. Mine seems to fluctuate alot also. The hottest I got it was 230 although I could have pushed it hotter. While accelerating up an on ramp you can see the temp rise, but once I get into overdrive it goes down or if I hit the overdrive off button while climbing I can watch the temp go back down. Generally around town mine runs from 125 to 180 Climbing hills it will get alot hotter than that. One reason it seems to dance around so fast is that the extra cooler is working and cools it off much quicker than with just the stock cooler. oh yeah, mine is a Phaze gauge.

Since I got the temp gauge, I drive a little more conservative. When you jump on the gas you can watch the temp rise almost as fast as the speedo. These trannies are better at making heat than anything else.

timw.

What's up man. I installed an auto guage tranny temp guage in my 92 4runner approximately 3 months ago. My setup is identical to yours (aftermarket cooler after stock) My temp guage sending unit is also installed on the rubber hose before fluid goes to radiator. I can honestly say that I see the same results that you and slosurfer see. What i have found out is that when you see the fluid cooling off it is because your torque converter has locked up (which occurs with both o/d on or off). It's amazing how conservative I began to drive once I started monitoring this guage. About 2 weeks ago i was driving home from phoenix, and my guage got up to 250. (t/c not locking up like it should) I need some new solenoids!

Remember that the temp youre seeing is the fluid as it leaves the torque converter. It doesn't necessarily reflect oil temp in the pan which should be roughly 30-40 deg cooler after going through stock and aftermarket cooler. (Info i found on an engineering site)

snap-on

Ya i know its the converter temp, and the temp going back in should be a good 50deg cooler (especially because of the aftermarket cooler) still makes me nervious....

BTW about the TC lockup... the other day comming home from work i couldnt get mine to lockup like it should. made driveing the truck a lot easyer because the motor floated in its 3K rmp sweetspot instead of the luggin 2.5K or screeming 4K (I HATE the valving on the A340H) I could run no OD but then im screaming at 4K trying to do 65 in 75 mph traffic. temp durring that time was 250 like you said. I had 5 more min of interstate so i just gritted it out IN OD.

ive considered revalveing it as that would fix my hatetred with the thing. Overall its ok not hauling anything in town. (other than just being short on power but hey its a 3.slow )

the other thing ive noticed... if "babying" it to kept temps in check... you get decent gass millage... 16-17mph (shocker i know) when before i got as low as 12 and avg 14.... (i really need some man hubs)

anyone else out there? at least im not the only one with this "issue" so that makes me feel better.

timw.

modifying that valve body is supposed to make a world of difference according to some, if you do it, let us know how it goes. To rich for my blood @ this time however.

Robinhood150

I have an aftermarket cooler plumbed in after the radiator and the gauge sender is plumbed in the rubber hose before the radiator.

I see the same temperatures. On flat freeway I can cruise for 20-30 miles and the temp stays around 180 or less. But on the hills or a stiff head wind, as soon as the torque converter unlocks it skyrockets up to 230 or higher. I don't let it go up to 250, I hit the OD button which seems to lock up the TC and the temps go down.

Bumper to bumper traffic on hot days is the worst. It'll easily stay up near 230 until I get some speed going and some wind through the cooler. I'd really like to find a e-fan for it, but in my unique location I need a 6 inch fan to fit.

Edit: I'm pretty sure my tranny has a problem though. The temp light has come on more frequently in the past few years than it did in the previous 10 years.

thefallman

think you guys need to install some oil thermostats and bigger aftermarket coolers

Robinhood150

But that would be fixing the symptom and not the cause.

thefallman

The cause is the automatic tranny. I'm not bashing automatics cause i love mine. You cant fix it. you can help it by keeping it cool.

You could help it some more by getting that AWS shift kit, to shift it manually.

But as long as you have an automatic transmission your going to have these issues. Its just part of the game.

The reason you see the spike when you step on the accelerator or are going up a hill is because the TC unlocks and that causes all kinds of heat to be generated.

I almost never drive around in O/D for one thing with 33 and 4.88s i just didnt have enough power with my 3.slow to do it. I could with the 3.4, but its one of the harder things to do to the tranny im not sure on exactly why it generates heat but i do know if you use O/D and pull or haul much wieght you will burn up your tranny in a hurry. The only time i put it in O/D even with the 3.4's power is when im on the highway and will be cruising at speed for awhile

The reason the valve body modification works is because it increases hydralic pressure in the transmission which increases clamping forces on the clutch packs. Which inturn decreases slippage and which causes less friction generated heat.

Robinhood150

There is one fundamental question that needs answering though. Is the temperature fluxation within normal operating conditions. If it is, then there's no need for additional cooling. Sure, better cooling is always better, but at some point you get diminishing returns.

If it's not running within specifications, then there must be another cause and additional cooling will only mask the cause.

thefallman

I cant say i disagree, because the reasoning is sound.

But i think your missing something. The reason for the tempature fluctions is because you are cooling oil with a medium that is at the same temperature if not higher then your optimal oil temperature. so there fore everytime you put a load to the transmission, you are increasing friction and dont have enough of a temperature differential in your coolant to keep the oil at a optimal tempature so it spikes.

The reason for this is that in stock aplications the manufacture was able to get by with using the engine coolant as a buffer, without using a oil thermostat, and keep the oil temperatures in a reasonable range, as long as you are using it in a manner that is consistant with the manufactures recomendations.

the problem with this is that you can get better effeciancy out of your engine if it is opperated at higher tempatures but if you operate at higher temperatures with the integrated cooling system, you will overheat your oils and they will not work properly.

I didnt advocate more cooling, i advocated differnt cooling. If you use a seperate cooler AND use a oil thermostat it will only allow the oil into the cooler when it is hot enough. therby reducing warm up times and the resultant wear on your drivetrain. but also if you use a thermostat and a seperate cooler you will have a greater temperature differential and your oil temps wont spike AS MUCH. They will still spike because of the nature of an Automatic Transmission. but it will round the spikes out more.

Quite a few differnt studies have shown that up to 80% of drivetrain wear is happens before oil reaches 170degrees.


No stock vehicle, that i know of, comes with oil thermostats. manufactures instead rely on the correct sized cooler to provide the correct amount of cooling for the application. the problem with this is spikes and dips. the reason for a thermostat is to provide a balance.

mt_goat

I found in the 2003 Tacoma FSM the oil temp idiot light comes on when the ATF hits 302 deg F and will go off when it hits 248 deg F.

My 2001 tranny has been reading around 160-180 just before the radiator cooler. I have an IPT valve body modification and these two extra coolers mounted between the radiator and AC condensor though.

trythis

Wow, two tranny coolers? Man I am feeling out done. I have one like yours for my 22re. Hauling a trailer, I never saw the at temp light go on, but I never used OD and kept ECT on.

thefallman

what size are your coolers goat, been meaning to ask you that for along time

slosurfer

It would be interesting to see if someone has the temp gauge but no aftermarket cooler, I wonder what kind of temps they are seeing. Just to clarify, I have never had an overheating problem, I just added the cooler as a preventative for bigger tires (33's w/ 4.88's) and hauling a small trailer. The highest I have got was 230 when I was going up highway 18 to Big Bear, which for those who don't know is really steep and windy. I am pretty sure my cooler is doing a good job, when I am on trails and it is almost 100 degrees out, my temp is usually at 150. I mainly see the spikes when o/d is on and I am on the freeway and it kicks down to go up a hill (which with 33's and factory 4.88's it doesn't take much) I usually just turn o/d off for the hills.

I have noticed that if I am on the freeway and turn o/d off for every little hill that makes the auto kick down, I can keep my temps really low. BUT, gas mileage will suck. Now I try to just turn o/d off for the longer hills on the freeway and will let the temp creep up a little bit, it cools off right away and I will get decent mileage. Unfortunately not too many flat places here, so I still have to turn o/d off alot.

timw.

i apologize in advance for the stupid question, but where would on install an oil thermostat? How about a cooler that would be up to the task of cooling the ATF w/o the use of the stock radiator cooler?

slosurfer

Also, I was talking to the pres. of the local 4wheel club about this. He is a tech for jeep dealership. He was telling me that the tranny in his cherokee is pretty much the same as mine except for the valve body. Anyways he saw my temp gauge at the dunes and I told him how I was amazed how hot it could get. I told him I could spike it to 230 and he said that that wasn't bad. He said when it starts spiking at 270-280 is when it gets bad. I know he's a jeep guy but I just thought it was interesting.

thefallman

a oil thermostat goes in the oil cooler out and return lines right as they exit the transmission or engine.

yes the jeep transmission is also an A340.

here are a few oil thermostats from summit
http://store.summitracing.com/egnsea...17&D=%2D124017

timw.

thanks for the info, much appreciated

mt_goat

IIRC they were the model 4454 here:
http://www.importperformancetrans.co...ers.shtml#main