Trans overheating???

[Former_Jeeper]

Not to ressurect the same topic, but a little different.....

So I have a 99 4runner, lifted (toytec ultimate) 265/75/16 tires, and shockworks bumper with 2 7" PIAA lights on the bumper (yes kind of blocking the grill) I also have on top a whitson rack with a spare tire mounted up there, and 4 kc lights on the front of it. NOt armored outside of rocksliders, roofrack, and bumper.

I live in Indianapolis and the weather has been around the 50's lately...

Ok so now the problem..

I recently bypassed my radiator and installed the BM 70268 based on other guys' opinions and what has worked for them.....I recently added a ScanGauge II so i can monitor my tranny temps.....and just driving on the highway i was fluctuating between 185-235!!! WTF around 85mph it was wanting to stay above 225. and it's not even hot out yet???

Does anyone else have this problem?? Thinking it might be an airflow issue, but unless i want to remove that light i guess my options are to go back to routing it through the radiator, or possibly adding a second trans cooler (Not sure if there is enough pressure or how good of an idea that is??)

ANyways I figure i would rather take a chance with a pink milkshake then, certain death with temps that at 50 degree ambient are shooting to 235 no doubt on 90 degree days will be 250 +.

Now in fairness when going 70 or below it was around 185. it was mostly uphill or when i got 80+ that it sky rocketed to 235.

And yes for sake of wondering it is properly placed and routed correctly (send in bottow, return at the top).

Don't want to resurrect bypass or not to bypass thread, but wanted to know if anyone else had this problem.

Thanks for any input

 

[shouldbeasy]

did you get the input and output outlets switched? I think I did that the first time... Ended up with higher than expected trans temps. Switched to a larger cooler (and switched the inlet and outlet) and temps went WAY down.

I'm closer to 160°F cruising, might hit 180°F on hills.

 

[fourwd1]

There's no way the stock in-radiator cooler will work better than a larger aftermarket one. It sounds like it doesn't have proper air flow through it. Get rid of some of the junk blocking it and see if it doesn't work better.
Also, do you know what the normal operating Temps of the trans should be?

 

[SpidermanGeek]

WTF around 85mph it was wanting to stay above 225. and it's not even hot out yet???

Now in fairness when going 70 or below it was around 185. it was mostly uphill or when i got 80+ that it sky rocketed to 235.

To me this is like saying "I sprinted a half-mile and I'm out of breath and sweating!!?? WTF!?"

I didn't even know 3rd gens could do 85MPH, lol... let alone one with bumpers and added wind resistance on the roof.

Did you try driving with the OD off, I heard that when the Torque Converter locks up, tranny temps shoot right up.

 

[Former_Jeeper]

yeah i was getting after it driving so I hope that is part of the problem....I do think it is an airflow issue I just didn't know if anyone else saw the same issue or if taking off the lights on a bumper would alleivate that?

I am not a trans specialist but I can say with a fair amount of confidence that around 180-200 is probably average/ideal, but that 235 at 50 degree ambient temp is way too hot.

And yes I have it routed so it goes from the trans to the bottom of the cooler and the top of the cooler spits is back into the trans......(which is debated, but according to BM is the proper way). Just from a guesstimate from an eyeball it is half blocked due to aftermarket bumper/lights.

Are any of you guys using a trans gauge and what are you guys seeing if running at 70268?

Is putting another cooler on and running two separate coolers a no no?

thanks for the input?

 

[Former_Jeeper]

and no i haven't tried driving with OD off.....I'm just curious what it will do with another 40 or 50 degree ambient temp increase in a couple months....

 

[jeremyc74]

I am not a trans specialist but I can say with a fair amount of confidence that around 180-200 is probably average/ideal, but that 235 at 50 degree ambient temp is way too hot.

You're absolutely right. I have a gauge installed in my RV and it rarely ever gets up to 190 degrees, and that's only at high altitude in high ambient temperatures. BUT! I found this old thread that might be good news:

http://www.toyota-4runner.org/3rd-gen-t4rs/126317-transmission-temp.html

I had a very similar experience while running Engineers pass in May. Mine was up around 270 with a new external cooler and the stock one. I worried the whole trip because it was 220-250 consistently the whole according to the scan gauge. I have since installed a mechanical gauge and it reads from 30 to 50 degrees cooler than the scan gauge, even reading right at the transmission output line. Long story short, I wouldn't trust the scan gauge.

 

[LittleCaesar]

Make sure that your 70268 is mounted right up against the condenser, right in front of the pathway of the fan. If not, temps can climb fast.

Also check the operation of the fan clutch as well.

 

[4eigner]

To me this is like saying "I sprinted a half-mile and I'm out of breath and sweating!!?? WTF!?"

I didn't even know 3rd gens could do 85MPH, lol... let alone one with bumpers and added wind resistance on the roof.

Did you try driving with the OD off, I heard that when the Torque Converter locks up, tranny temps shoot right up.

Think you have that last part mixed up. When the torque converter is slipping it creates more heat from all the friction, as opposed to when it's locked up.

Going uphill at 85mph is strenuous on these motors. I've done it while running the larger b&m cooler and temps ran somewhere in the 230-240 range. Needless to say, I quit doing that really quick. OP, you'll either need to do some serious trans cooler upgrades, or keep the climbing speeds down to something more manageable for these trucks if you want to give your transmission any decent lifespan. With overdrive off, you should have the torque converter lock up and trans temps decrease, but at the expense of higher engine rpms, gas mileage, and engine wear.

 

[Former_Jeeper]

Little Caesar yes it is mounted correctly exactly as you described......I guess what I'll take away is if I don't want to reroute it through the radiator I just can't drive it like I stole it

Does anyone who has it stock through the radiator see any temps above 185???

 

[slides]

I have the 70268 Trans cooler and it's too damn small. Even on my commute home which is 4 miles the Trans gets up to 130f. I'm upgrading to a 20000btu cooler, the worst I had it was 210 fwhile messing around on a lake when it was 15deg out.

Get a bigger cooler and u will be good

 

[19963.4lsr5]

Driving with the trans out of lock up (TCC) will put all kinds of heat in it.

 

[Former_Jeeper]

So you have an idea of the airflow this is what i was talking about

 

[SpidermanGeek]

Think you have that last part mixed up. When the torque converter is slipping it creates more heat from all the friction, as opposed to when it's locked up.

Going uphill at 85mph is strenuous on these motors. I've done it while running the larger b&m cooler and temps ran somewhere in the 230-240 range. Needless to say, I quit doing that really quick. OP, you'll either need to do some serious trans cooler upgrades, or keep the climbing speeds down to something more manageable for these trucks if you want to give your transmission any decent lifespan. With overdrive off, you should have the torque converter lock up and trans temps decrease, but at the expense of higher engine rpms, gas mileage, and engine wear.

Yeah, sorry, my bad. I just knew that driving with OD off reduces temp, but I got the TCC lock-up effect reversed.

 

[Brveagle]

I am running the same as you. 99 Sr5. Auto tranny. Scangauge II. B&M cooler. (NO LIGHTS THO)

Yesterday during driving through the kansas flint hills with a small 5x8 flatbed trailer and dirtbike on it with all my gear i was running around 170 degrees at 80 mph. Ambient temperature was 75. I'd hit 200 degrees when going up a hill in overdrive, but it'd cool right down once the hill climb was over.

I really think your lights are blocking the necessary windflow.

 

[jgue467]

There's no way the stock in-radiator cooler will work better than a larger aftermarket one....
Also, do you know what the normal operating Temps of the trans should be?

Actually it will work better. Because it is a liquid to metal to liquid cooling mechanism vs. liquid to metal to air. The latter has far less BTU cooling ability. The runners engine radiator temps won't allow the trans fluid to heat up much beyond the normal 194-199 engine water temps, will allow it to warm up faster and keep in the 'zone' better too. Adding in the extra trans cooler is the best on top of new(er) stock radiator. Temps s/b same as the engine - how Toyo designed it. :cowboy:

 

[the great him]

so you have two options, either remove the lights, or get a bigger cooler, i used the 70264 cooler and found that even that one was not enough so i ended up buying a second cooler with an electric fan on it. idk why people buy that pathetic 268 cooler, its anemic, and for a friggin car. B&M rates those at optimal conditions, meaning there is a big fan directly behind the cooler, and nothing in front of it with perfect airflow and probably around 70* ambient temps. -the bigger cooler(of you could even run both of them i guess) is much cheaper than taking the hit on the lights, i think that 264 was like $60, those PIAAs are like $3-400, you do the math.

you could always remove the lights and just do the same again and see what the temps are and then go from there, but im sure you are gonna want a bigger cooler. and you really cant go too cool -you can but as long as you are over the 130* mark you are fine basically if the trans will shift into overdrive you are warm enough and it will do that at just under 120*

 

[SpidermanGeek]

so you have two options, either remove the lights, or get a bigger cooler, i used the 70264 cooler and found that even that one was not enough so i ended up buying a second cooler with an electric fan on it. idk why people buy that pathetic 268 cooler, its anemic, and for a friggin car. B&M rates those at optimal conditions, meaning there is a big fan directly behind the cooler, and nothing in front of it with perfect airflow and probably around 70* ambient temps. -the bigger cooler(of you could even run both of them i guess) is much cheaper than taking the hit on the lights, i think that 264 was like $60, those PIAAs are like $3-400, you do the math.

you could always remove the lights and just do the same again and see what the temps are and then go from there, but im sure you are gonna want a bigger cooler. and you really cant go too cool -you can but as long as you are over the 130* mark you are fine basically if the trans will shift into overdrive you are warm enough and it will do that at just under 120*

My 70268 just got shipped! lol.

Although I'm in Canadian Climate and don't tow. I'm bypassing the stock rad/cooler until I replace the rad, then I will hook-up in series.

I'm more concerned about overcooling on cold days which is why I didn't go for the 264.

I also drive like a grandpa. Going over 65MPH on 33's with dynabeads, 3" lift and no sway bars is a little nerve racking IMO.

 

[the great him]

My 70268 just got shipped! lol.

Although I'm in Canadian Climate and don't tow. I'm bypassing the stock rad/cooler until I replace the rad, then I will hook-up in series.

I'm more concerned about overcooling on cold days which is why I didn't go for the 264.

I also drive like a grandpa. Going over 65MPH on 33's with dynabeads, 3" lift and no sway bars is a little nerve racking IMO.

the main point for doing the after makret cooler on these is to by-pass the radiator to eliminate the risk of the "pink milkshake", running them in series completely negates that. not to mention the factory "cooler" is not a cooler, its a temp regulator, it keeps the temps at the same temp as the coolant, it is not a cooler at all. if you overheat you heat the trans fluid, if you overheat the trans fluid you will then raise the coolant temps... you said it yourself, you dont tow and you drive like a grandpa, so why get the aftermarket cooler? over cooling? yeah not going to happen unless you are running at like 80 on the fwy with wide open air space and sub zero temps. i was running dual coolers and even days with temps in the teens and doing 60+ on the fwy i was still at like 135*+. again if your trans will shift into overdrive you are fine. the trans will not shift into overdrive if the temps are too cold. if you are running bigger tires, on stock gearing i will guaranty you will make plenty of heat.

running them in series will not do anything, the radiator will just reheat the fluid muting any cooling you possibly gained using your cooler. your only option for that would be to run the cooler after the radiator, but even then you are just fighting yourself. these coolers are meant to be stand alone units. vehicles that come with transmission coolers, do not have the transmission fluid running the the radiator first or even after the cooler. its always stand alone.

 

[SpidermanGeek]

So the debate rages on then...lol.

I've read so many threads on here about the trans cooler - to bypass or not - and I'm still conflicted.

the main point for doing the after makret cooler on these is to by-pass the radiator to eliminate the risk of the "pink milkshake"

For me, the plan right now is to bypass for this exact reason. I guess that if I don't see any trans temp issues after 4 seasons, it's a safe bet I can just leave that setup the way it is, but I still have a lot of people telling me that the cooler itself won't be enough or will keep the trans from going to temp in the winter.

Pulling my hair out now, lol.