Radiator have effect on ATF warming??

[4xt4r]

Trying to decide whether to bypass radiator & run external ATF cooler or replace radiator to prevent pink milkshake on my '98 runner 240k mi.
Does the radiator help the ATF warm up faster when starting cold in the morning?
My transmission will not shift from 2nd to 3rd gear until it has warmed up & I am reluctant to bypass the radiator if it will slow down the warm up process.
Thanks!!!

 

[Antman]

Trying to decide whether to bypass radiator & run external ATF cooler or replace radiator to prevent pink milkshake on my '98 runner 240k mi.
Does the radiator help the ATF warm up faster when starting cold in the morning?
My transmission will not shift from 2nd to 3rd gear until it has warmed up & I am reluctant to bypass the radiator if it will slow down the warm up process.
Thanks!!!

Short answer = YES, it does help warn up the ATF as well as keep the temp in check.

 

[BlackCat914]

Trying to decide whether to bypass radiator & run external ATF cooler or replace radiator to prevent pink milkshake on my '98 runner 240k mi.
Does the radiator help the ATF warm up faster when starting cold in the morning?
My transmission will not shift from 2nd to 3rd gear until it has warmed up & I am reluctant to bypass the radiator if it will slow down the warm up process.
Thanks!!!

The shifting issue is normal. They all do it. The B&M coolers have a thermal bypass that keeps the fluid from going through the cooler when it's cold. I had one on my 97 and it warmed up exactly the same as when the cooler in the radiator wasn't bypassed.

 

[tx_shooter]

If you wanted to add peace-of-mind you could install a 160 degree thermostat between the transmission and the cooler. That way the transmission would have to come up to 160 degrees (low end of optimal temp) before the cooler would become a factor. I am planning on doing this to my 4R this weekend.

 

[IsaiahC]

You shouldn't have any problems with it warming up in Texas. Just get a B&M with a bypass then use the zip-tie mounts to mount it to your radiator/condenser. Here's one: http://www.amazon.com/70264-SuperCooler-Automatic-Transmission-Cooler/dp/B000CIIDZE

 

[nissanh]

Question

If you wanted to add peace-of-mind you could install a 160 degree thermostat between the transmission and the cooler. That way the transmission would have to come up to 160 degrees (low end of optimal temp) before the cooler would become a factor. I am planning on doing this to my 4R this weekend.

Isn't the trans fluid supposed to circulate every time the engine is running?
If the thermostat is closed the pressure builds up in the fluid and may damage the transmission.

Buy the trans cooler that has a by-pass valve at low temperatures.

 

[4xt4r]

Isn't the trans fluid supposed to circulate every time the engine is running?
If the thermostat is closed the pressure builds up in the fluid and may damage the transmission.

Buy the trans cooler that has a by-pass valve at low temperatures.

Good point.
Thanks everyone for your input!!!

 

[tx_shooter]

Isn't the trans fluid supposed to circulate every time the engine is running?
If the thermostat is closed the pressure builds up in the fluid and may damage the transmission.

Buy the trans cooler that has a by-pass valve at low temperatures.

You do not understand how the thermostat works -

Good point.
Thanks everyone for your input!!!

Only a "good point" if he knew what he was talking about. This is why the Internet is dangerous.

It receives the fluid in and flows it past a thermostat. If the thermostat is not up to temperature it is "closed" and loops the fluid back out a port to return to whatever the source was. So at this point we have a loop coming out of the trans through the thermostat and returning to the trans that is less than 160 degrees.

Once the fluid reaches 160 degrees the thermostat begins to slowly open up allowing fluid to pass to the external cooler before returning to the transmission. This way the fluid stays at slightly above 160 degrees. At this point the cooler comes into play in managing the temperature of the fluid as long as it is above 160 degrees.

There is not a pressure issue or flow issue.

 

[nissanh]

If you are teaching

You do not understand how the thermostat works -



Only a "good point" if he knew what he was talking about. This is why the Internet is dangerous.

It receives the fluid in and flows it past a thermostat. If the thermostat is not up to temperature it is "closed" and loops the fluid back out a port to return to whatever the source was. So at this point we have a loop coming out of the trans through the thermostat and returning to the trans that is less than 160 degrees.

Once the fluid reaches 160 degrees the thermostat begins to slowly open up allowing fluid to pass to the external cooler before returning to the transmission. This way the fluid stays at slightly above 160 degrees. At this point the cooler comes into play in managing the temperature of the fluid as long as it is above 160 degrees.

There is not a pressure issue or flow issue.

OP is new and your answer does not help him, because he do not know about how a thermostat works. Your second reply is well explained!

 

[4xt4r]

You do not understand how the thermostat works -



Only a "good point" if he knew what he was talking about. This is why the Internet is dangerous.

It receives the fluid in and flows it past a thermostat. If the thermostat is not up to temperature it is "closed" and loops the fluid back out a port to return to whatever the source was. So at this point we have a loop coming out of the trans through the thermostat and returning to the trans that is less than 160 degrees.

Once the fluid reaches 160 degrees the thermostat begins to slowly open up allowing fluid to pass to the external cooler before returning to the transmission. This way the fluid stays at slightly above 160 degrees. At this point the cooler comes into play in managing the temperature of the fluid as long as it is above 160 degrees.


There is not a pressure issue or flow issue.[/QUOTE

Ok,gotcha,I did not know the transmission had a dedicated t-stat that had ATF Flowing through it.
Thanks for enlightening me!!!
At that point, the external transmission cooler would not inhibit the warming process,right??

 

[4xt4r]

OP is new and your answer does not help him, because he do not know about how a thermostat works. Your second reply is well explained!

Ok,thanks.
I was not aware that the transmission had a dedicated thermostat solely for warming & limiting ATF temp.

According to this fact, the ATF would warm at the same rate whether it was running through the radiator "stock" or only running through an external cooler right??
Thanks !!

 

[kball]

um wow. well I might be waaay behind in tech these days but I've never heard of a thermostat built into a transmission. Some new trucks and maybe cars have trans fluid warmers which basically run the trans fluid through something similar to our radiator cooler setups but these are normally mounted right to the block like our engine oil coolers are.

And your trans taking a while to shift when cold has nothing to do with warming the trans and everything to do with warming the engine.

 

[tx_shooter]

The thermostat is not built into the transmission. I am adding it to the cooling loop. Let me get to a computer later and I will find/make a diagram of what is happening g.

 

[Arnezie]

If you wanted to add peace-of-mind you could install a 160 degree thermostat between the transmission and the cooler. That way the transmission would have to come up to 160 degrees (low end of optimal temp) before the cooler would become a factor. I am planning on doing this to my 4R this weekend.

Why do this the B&M basically has this built in its a thermal bypass.:der:

 

[tx_shooter]

Why do this the B&M basically has this built in its a thermal bypass.:der:

I went the larger B&M that does not have the thermal bypass for multiple reasons. Please see below for better explanation.

1st - the B&M I am running now is not keeping up in +100 degree weather in Texas when driving in the city. I average 35k miles a year for work and a good bit of that is city driving.

2nd - the larger cooler will be more effective for cooling when I am taking my 4R off in the dirt and crawling with it. High RPMs/ low-no MPH and the regular B&M did not look promising.

3rd- my 4R is supercharged and I had found other examples where the s/c trucks have issues with higher transmission temps. I do have plans to put a "shift kit" in it but cannot afford to do so at this moment.

I checked with a few transmission shops - local and web - and continually was told that 160 is the preferred low end operating temp. After a few conversations with different transmission shops regarding off road/daily driving use they all said to get the transmission fluid to 160 degrees for proper operation. Then keep it at 160 degrees for long life and proper operation.

Considering +100 degree weather is not rare in Texas I decided to go with a slight overkill method (Marine Infantry habit) and worked out a setup that gets the transmission fluid to 160 degrees and then will keep it at 160 degrees in all but the most extreme cases.

______

As for your crazy smiley -

Yes - some B&M coolers do have the Low Pressure Drop system (LPD) built into the cooler. Those coolers are the #70255, #70264, and #70268. Pretty much all of their transmission designed coolers with the 3/8s nipple already attached to the cooler. The #70266 that I have decided to go with does not have the LPD system build into it as it is designed for heavier cooling use. It comes with 1/2" NPT female fittings read to connect to whatever I screw into the NPT fitting. Since the #70266 does have the cooling capacity I want but does not have the LPD design I found a solution that still allows for proper transmission temps and cooling.

 

[tx_shooter]

As for the getting back to the transmission cooler and thermostat for controlling the temps.

First - The standard way people install auxiliary coolers. From the trans to the stock radiator based cooler; then to the aux cooler before going back to the transmission.



Second - The item in the middle with "Endcap" pointing at it is the thermostat that opens at 160 degrees fluid temp. This is one acceptable way to install the thermostat and is commonly recommended so as the aux cooler only adds cooling capacity when the fluid really needs to be cooled back down to preferred temps. When temps exceed 160 degrees the thermostat sends fluid through the cooler to cool it back down. When the fluid reaching the thermostat is -/= 160 degrees the thermostat closes so as to route the fluid back to the transmission.



Since we have 3rd gen 4Runners we have the pink milkshake issue and commonly bypass the stock radiator so as to avoid this issue. Hence I will run this setup. Out of the trans to the thermostat where the fluid will be routed back to the transmission as long as it is under 160 degrees. Once fluid temps are =/+ 160 degrees the thermostat will open up and send the trans fluid to the external cooler and make use of the B&M 70266 larger cooling capabilities. (I am trying to find where I found that the NPT fitting B&M coolers do not have the internal cool fluid bypasses build in.)




Sorry about the MS Paint skills - it is early and I need to go pick up my supercharger housing so I can finish rebuilding it today. I'll try to check back asap.

 

[jgue467]

...
Does the radiator help the ATF warm up faster when starting cold in the morning?
My transmission will not shift from 2nd to 3rd gear until it has warmed up...

Much faster. I live in Austin too and my bypassed trans cooler causes the trans to need to be driven 30-45 miles before i finally reaches 'normal' operating temps in our 'winters' - it makes it to 145-150 in 5 miles. Before the bypass, it would reach normal temps in 5 miles. Not sure what that means for efficiency or longevity. Thoughts anyone?

Your trans should still shift up, just not at the normal speed for the given amount of pedal pressure, when initially started for the day (stone cold) the ecu makes the shift point for 2-3 higher to allow the engine to warm up faster than without the delayed shift.

I'm thinking of going back to the original toyo trans cooler design - maybe. :cowboy:

 

[tx_shooter]

Which Hayden cooler did you go with? If it has the built in 3/8" nipple if should have the Low Pressure Drop system in it. How effective this system is I do not know.

 

[4xt4r]

As for the getting back to the transmission cooler and thermostat for controlling the temps.

First - The standard way people install auxiliary coolers. From the trans to the stock radiator based cooler; then to the aux cooler before going back to the transmission.



Second - The item in the middle with "Endcap" pointing at it is the thermostat that opens at 160 degrees fluid temp. This is one acceptable way to install the thermostat and is commonly recommended so as the aux cooler only adds




cooling capacity when the fluid really needs to be cooled back down to preferred temps. When temps exceed 160 degrees the thermostat sends fluid through the cooler to cool it back down. When the fluid reaching the thermostat is -/= 160 degrees the thermostat closes so as to route the fluid back to the transmission.



Since we have 3rd gen 4Runners we have the pink milkshake issue and commonly bypass the stock radiator so as to avoid this issue. Hence I will run this setup. Out of the trans to the thermostat where the fluid will be routed back to the transmission as long as it is under 160 degrees. Once fluid temps are =/+ 160 degrees the thermostat will open up and send the
trans fluid to the external cooler and make use of the B&M 70266 larger cooling capabilities. (I am trying to find where I found that the NPT fitting B&M coolers do not have the internal cool fluid bypasses build in.)




Sorry about the MS Paint skills - it is early and I need to go pick up my supercharger housing so I can finish rebuilding it today. I'll try to check back asap.

Thanks Tx shooter for the drawings & description, it all makes good sense now.
I thought you were saying the transmission had a t-stat , which I had never heard of.
Thanks again!!!

 

[StreetCreeper]

Thermostats fail. It would suck if it failed while closed. I wonder how long it would take before damage was done.