Transmission cooler: to by-pass the radiator or not to by-pass it

[Mint]

Im sorry, by "bigger cooler" I simply meant bigger than if you put a cooler in series with your rad.



Yeah, some of the B&M models have that.



Thats the thing, I spent a stupid amount of time searching through forums for which cooler will provide sufficient cooling on its own but I didnt get any straight forward answers. Eventually I gave up and decided to go with the biggest rad I could fit(hayden 679) with a bypass thermostat(derale 13011) to prevent over-cooling.

So you just bypassed then with that setup? Did you replace the radiator too though or still have the stock one? Do you tow?

 

[redstar]

So you just bypassed then with that setup? Did you replace the radiator too though or still have the stock one? Do you tow?

Ya, I bypassed.
Didnt replace the rad, just flushed it and sealed it.
Havent towed yet.

 

[slides]

I live in cold minneapolis, i use to drive on the highway all the way to work which was 20 miles with trans temps starting out at 60 and slowly crawl to 90 by the time i got to work. All highway so its not changing gears or anything. I have read that as long and your not towing those temps are fine. Im not worried im actually going to throw a bigger cooler in this summer since my current one gets a little too warmn during the summer.

 

[ajonesnv]

I live in cold minneapolis, i use to drive on the highway all the way to work which was 20 miles with trans temps starting out at 60 and slowly crawl to 90 by the time i got to work. All highway so its not changing gears or anything. I have read that as long and your not towing those temps are fine. Im not worried im actually going to throw a bigger cooler in this summer since my current one gets a little too warmn during the summer.

Do you have a thermal bypass on the lines?

If not I would recommend one. It may never be an issue, but some of the ports in the tranny are very small and may have a hard time getting fluid that cool. In addition if you plan on a larger cooler in the summer then consider it will be even colder in the winter.

 

[Rifter]

Im planning on adding a cooler and bypassing the factory one, to avoid the issue of it leaking coolant into the trans.

It doesn't get cold enough here for me to worry about warming up the transmission fluid.

Whats a good size?

 

[runner823]

No disagreement here.^ My only point is don't delete the radiator in hopes that a small air to liquid cooler will be sufficient.


Of course you need an extra cooler when hauling a load. Thats why dealers call it a tow PACKAGE because its more than just a hitch install. We agree here too ^



Wow. Nice build but it looks like you went to a lot of trouble and expense to bypass the radiator. I'm guessing your truck would have been better served to use the radiator and then that monster B&M with a fan mounted to it. I would bet dollars to dough nuts that it would work better than what you have now. The key is to lower the fluid temp with the coolant and then bring it lower from there. If you get mud on those two front coolers they will offer little cooling, if at all. Think if you had left the radiator circuit, the 220 would have been more like 180. When your fluid temp rises above 180, the fluid begins to degrade. 220 will certainly be too hot if run for prolonged periods, like offroading.


Not so. Your dual coolers would have lowered the temp an additional 20 degrees each from whatever the radiator was sending through them.




Are you really serious here?? There are millions of cars and trucks on the road using in-radiator trans coolers that are not leaking or failing thru their entire life cycle. I don't agree with you at all. Just buy a better radiator that's not made by toyota. Problem solved. This is the hysteria I've touched on before. The benefits of an in radiator cooler far outweigh the internet hyped fears of strawberry milkshake.




I bet you sleep with the lights on. Don't you?

One last comment here. Look at the trouble you went through to bypass your radiator. I would guess that the average person deleting their radiator cooler isn't as sophisticated as you and simply buy a $60 B&M and call it a day. Let's be honest here. Your setup is probably about a $300+ modification as a DIY. The twin huge coolers, the fan, the inline temp switch, gauge/pod and extras I can't see in the pictures. Again, I would say this. Buy a new Koyo radiator on ebay for $120 shipped and add a $^0 B&M cooler and you will never have to worry about it again.

My only concern here as a new member on T4r.org (now I question why I even give a crap, for all the heat I'm taking) is that people first understand what they are risking before they go off half-cocked. From what I have noticed from spending some time here, is that more guys than not are tight on money and a major transmission repair would not be in their budget. That's all.

OP, their is no point to this thread. If you and I started a thread titled "coolant in oil due to failing oil cooler". Ever dumbass on this forum will by pass that cooler too.
Think about this.. you're trying to convince a group of people who reads and throws hundreds of dollars in parts to fix their car problems.
How many times have you read, "misfire help!!". Then follow it with I replaced wires, plugs and coils and still did not fix it. Right there they just spend over 100 hundred. Then they update with, replaced fuel filter and clear MAF, still not fixed.
To me that is dumbass move to keep throwing parts. Why not just spend the money and take to a dealer or good aftermarket shop to diagnose it.

My co-worker I gets a kick out these dumdass that do stupid things. Duel trans cooler, WTF!!! He should just put a second radiator for his transmission that's bigger than engine one.

Dumbass why did I joint T4R???
There are a Small % in there like OP that actually knows what they doing; and, those are the ones I like reading. But there are those I look at and just:lmao::lmao::lmao::lmao::lmao:

 

[LeeMajors]

So, in mild climate with no towing, an external trans cooler should be fine right?

 

[Spanky_11]

I have a question, and forgive me if this has been answered earlier in this thread. I live in Kansas, it gets hellacious hot in the summer and COLD in the winter. I want to put an external trans cooler in my 4Runner to avoid the rad failure/milkshake, is there any type of in-line thermostat that would only allow the fluid into the cooler after it has reached the temp that it actually needs cooling at? I'm just worried the fluid would take forever to warm up in the winter months and possibly damage the trans. Thanks.

 

[allwheeldrive]

Been running mine with no issues for 3 years now, consistently seeing sub zero temps throughout winter.

 

[zdfhh]

Second, it cools the transmission better than just an air-cooled aux cooler can do. A liquid to liquid cooler is far more efficient than an air to liquid cooler.

 

[Brveagle]

13 pages of beating a dead horse...

If you wanna run a cooler, run a cooler.
If you wanna stay stock, make sure you are proactive in regards to replacing your radiator.

 

[ajonesnv]

I have a question, and forgive me if this has been answered earlier in this thread. I live in Kansas, it gets hellacious hot in the summer and COLD in the winter. I want to put an external trans cooler in my 4Runner to avoid the rad failure/milkshake, is there any type of in-line thermostat that would only allow the fluid into the cooler after it has reached the temp that it actually needs cooling at? I'm just worried the fluid would take forever to warm up in the winter months and possibly damage the trans. Thanks.

Yes, google Thermal Bypass, it is covered in many places. I use one due to my trips to Idaho.

 

[amalik]

[MENTION=121191]Mint[/MENTION], the bypass technology based on the fluid is called LPD.

You can read about it here

transmissioncoolers.us: Tru-cool thin coolers

 

[Mgyver1]

I have a question, and forgive me if this has been answered earlier in this thread. I live in Kansas, it gets hellacious hot in the summer and COLD in the winter. I want to put an external trans cooler in my 4Runner to avoid the rad failure/milkshake, is there any type of in-line thermostat that would only allow the fluid into the cooler after it has reached the temp that it actually needs cooling at? I'm just worried the fluid would take forever to warm up in the winter months and possibly damage the trans. Thanks.

The TruCool and B&M coolers with the built in barbs have a low pressure drop which allows the fluid to bypass the main part of the cooler until the fluid warms up. Some people insist on also adding an external thermal bypass insisting it keeps their temps more consistent, and some say the external bypasses cause overheating problems. There's threads for and against. Best thing to do is start out with just the cooler with the built in LPD and have a gauge. If your temps consistently don't get warm enough then add an external bypass. You also need to do your own research on what temp is cool enough as there's also differing opinions on that. Some say there's no such thing as too cool and some say your temps should never get below 180.

 

[Drcoffee]

Holy crap! This horse has been beaten so hard and for so long it looks like a stain on the ground.

Its all about thermal efficiency. If you go cheap and put a single thin cooler on the truck and bypass the radiator, you are going to have trouble. If you spend some money and get the right setup, whether its two coolers or one giant cooler and fans and all the gimmicks to go with it ($$$$$), you will be just fine.

I started this thread because a few on here were telling others that its okay to put anything on the tranny and the world will be safe from all strife. Nobody ever reads beyond the headline. Evidence all the STUPID questions 13 pages later.

Look, if you don't want transmission failure, keep your trans fluid cool. If you live in Utopia where every day is just perfect and all you do is drive down hill, then use a single cooler. If you can can be assured that you will NEVER EVER EVER tow, climb, drive in the desert or moderate heat, or nothing below 40*, then you will be fine. If you CAN NOT PREDICT THE UNPREDICTABLE, then do it right. And doing it right means spending more than $30 on ebay for a fin and tube cooler designed for an electric golf cart.

Why is this so difficult??

Where's my coffee at? :zoom:

 

[Scramble]

Why did I just read through this entire thread when I have a manual? :bump2:

 

[infamousRNR]

[MENTION=78997]Drcoffee[/MENTION]

when bypassing the RAD with a B&M trans cooler, would it be appropriate to purchase a MANUAL RADIATOR for an AUTO 4runner since you won't be using that line>?

or should you just leave it plugged and get an Auto one?...



. . . . .

 

[MikeOregon]

WOW, this was an interesting thread to read. Thanks all... I learned a lot.

I have a 2000 T4R ltd with S/C that I am starting to tow a R-Pod 171 TT with. Total tow weight is probably a bit over 3k fully loaded with everything and ready to camp. The 4R does pretty well overall if we don't get in a hurry and stay out of overdrive (4th). I knew I should have an auxiliary tranny cooler in this situation, hence finding this thread.

I find it interesting how divided people are on this subject considering I think they are all right to some degree because of varying situations and needs. I found the following info on the Hayden site after reading this and think it states this indirectly and wanted to share the second half of that page for what it's worth:

Transmission Oil Coolers
Q. The trans cooler in the radiator is leaking and is expensive to repair. Can I use a Hayden transmission cooler to eliminate it?
A. Yes. Always choose one of the larger Hayden coolers when eliminating the radiator cooler to compensate for the loss of cooling from the radiator. In most installations we recommend use of the radiator tank cooler to provide maximum cooling and to comply with most manufacturers warranties.
Q. Should the cooler be installed before or after the radiator?
A. Hayden recommends installing the auxiliary cooler after the radiator to return the coolest fluid directly to the transmission. Installing the cooler before the radiator will still provide additional cooling and may be necessary in some difficult access applications.
Q. Can you over cool the transmission fluid?
A. Transmissions are not highly sensitive to cool operating temperatures. However, in sub-zero (20-30° F) weather conditions transmission fluid can actually gel up in an external cooler and cease to flow, causing damage. Use of the radiator cooler actually helps warm the fluid under these conditions. It is critical in extreme cold conditions to use the original equipment cooler in series with the auxiliary cooler and allow the vehicle to warm up before driving.

So as I interpret this....... NOPE! I'm not even going to go there :wink2:

Cheers!

 

[Nelsonmd]

Holy crap! This horse has been beaten so hard and for so long it looks like a stain on the ground.

Its all about thermal efficiency. If you go cheap and put a single thin cooler on the truck and bypass the radiator, you are going to have trouble. If you spend some money and get the right setup, whether its two coolers or one giant cooler and fans and all the gimmicks to go with it ($$$$$), you will be just fine.

I started this thread because a few on here were telling others that its okay to put anything on the tranny and the world will be safe from all strife. Nobody ever reads beyond the headline. Evidence all the STUPID questions 13 pages later.

Look, if you don't want transmission failure, keep your trans fluid cool. If you live in Utopia where every day is just perfect and all you do is drive down hill, then use a single cooler. If you can can be assured that you will NEVER EVER EVER tow, climb, drive in the desert or moderate heat, or nothing below 40*, then you will be fine. If you CAN NOT PREDICT THE UNPREDICTABLE, then do it right. And doing it right means spending more than $30 on ebay for a fin and tube cooler designed for an electric golf cart.

Why is this so difficult??

Where's my coffee at? :zoom:

Agreed that this has been beating to a horsey pulp, but -10 pts for not using the tailor made emoji... :deadhorse:

Just to clarify, I think your point was to use an APPROPRIATE single cooler if you decide to go the bypass route. There are of course conditions where a single external cooler will not be sufficient, but many of us have been running a single B&M or tru-cool cooler and from texas heat to Canadian freeze, the tranny temps have been fine. Still not a scientific study, but there are so many of us with single coolers that I think it is alot better than any of us just stating that it is or isn't ok because of our personal experience.

Overall though, yeah, the horse is dead and mutilated. There is more than enough info in this thread and in others if you search to make the decision. And using a cheapo ebay cooler is a dumb idea. There are ample affordable options with a good reputation out there. Don't try to get cute with it, it is your tranny after all, it's important and expensive, so treat it well.

 

[Nelsonmd]

[MENTION=78997]Drcoffee[/MENTION]

when bypassing the RAD with a B&M trans cooler, would it be appropriate to purchase a MANUAL RADIATOR for an AUTO 4runner since you won't be using that line>?

or should you just leave it plugged and get an Auto one?...



. . . . .

Assuming they have the same mounting points, it wouldn't matter either way. Why bother getting a manual one though? If you plug the tranny cooler ports, there's really no difference, so you aren't gaining anything, and the auto one is probably alot more common.

I would stick with the auto one anyway in case you decide to change it to running the external in series down the road. I can't imagine the cost difference for not having the tranny cooler on the rad is worth it to box yourself out of the option...