Which aux tranny cooler for my tacoma?

[sixstringsteve]

Slow rockcrawling isn't easy on a stock transmission, especially when you're pushing a heavy rig with bigger tires. I'm also worried about the strawberry milkshake issue when the trans fluid mixes with the antifreeze (not common, but very costly when it happens).

I'm looking for an aux tranny cooler so I can bypass the stock one.

Here are my concers:

1) an aux cooler may keep the trans fluid too cool initially. The stock design uses the radiator to heat the trans fluid right off the bat. That keeps it warm enough to be in operating temp in the winter.

2) do I need a line temp gauge?

3) do I need a fan in front of it?

4) how big do I need if I bypass the stock one?


I found these two.

http://www.partsgeek.com/lqly59b-to...ma+Automatic+Transmission+Oil+Cooler+-+Hayden

http://www.partsgeek.com/ld9bzdv-toyota-tacoma-automatic-transmission-oil-cooler.html


Anyone have any experience with an aux tranny cooler?

 

[dutchman]

I've got this one on my 01 4runner:http://www.amazon.com/70268-SuperCooler-Automatic-Transmission-Cooler/dp/B000CIGE9G

I hadn't had any issues the last 2 winters with it on there. I know on the later 3rd gen 4runners you can monitor tranny temps with a scan gauge or similar device. A fan in front on your aux cooler might be over kill, the factor fan pull enough air through. There are some guys on t4r.org that have gone with a bigger cooler, but the 70268 is the most popular. The bigger you go, the more space it takes on the radiator. Installing isn't overly difficult either.

Does your truck still have the factory radiator? If the radiator has been replaced recently you may not need the cooler, unless you just want to prevent the dreaded milkshake.

 

[Gravy]

Just slap an aux cooler from an explorer on there for $5 from junkyard and call it good.

 

[TurboMinivan]

I'm looking for an aux tranny cooler so I can bypass the stock one.

You may need to re-think this strategy (see below).

an aux cooler may keep the trans fluid too cool initially.

It may keep the fluid too cool at other times, also... and this can be undesirable on a computer-controlled transmission.

Back in the Good Old Days (tm), transmissions were hydraulically controlled. No fancy computers for us! As a result, low fluid temperature wasn't critical to their function. Back when I used to drag race my turbo minivan with its 3-spd hydraulic automatic, I ran the biggest trans fluid cooler I could find for sale--the chart on the back of the box said it was designed for big block V8 full-size RVs towing large trailers in the mountains (I am dead serious). In my van's case, my fluid could not be too cool thanks to how I abused the converter at the track, and this cooler helped the trans live a long life.

Nowadays, most slushboxes are computer controlled. Among other parameters, the computer monitors the fluid temperature; if the fluid is below a minimum desired temperature, the shifting logic can be affected. One example: before you get up to a certain temp, the converter will not lock and instead remains unlocked at all times. Because of this, most modern heavy duty vehicles with factory-installed auxiliary coolers will route the fluid as follows:

(transmission) --> (aux cooler) --> (integrated cooler) --> (transmission)

By routing the fluid through the cooler that is integrated into the radiator after it runs through the aux cooler, this ensures the fluid does not drop below the minimum temperature threshold. This allows the transmission to perform as it was designed, while the aux cooler helps make sure all excess heat is rejected. If your Tacoma transmission is computer controlled, I'd suggest you route your cooler in this manner (unless you find/have information from Toyota that says it is okay to do otherwise).

do I need a fan in front of it?

Quite unlikely, assuming your engine has a mechanical radiator fan. I'd just mount the aux cooler in the path of this fan and be done with it.

The cooler linked above is a good choice because it is a stacked plate design. This type of cooler is more durable and more thermally efficient than a tube and fin design, plus it typically has less flow drag through its core (which means it minimizes ambient air flow losses through the radiator that sits behind it). I would strongly urge you to avoid a tube and fin design. Photos for clarification:

Stacked plate:

Tube and fin:

HTH

 

[sixstringsteve]

I've got this one on my 01 4runner:http://www.amazon.com/70268-SuperCooler-Automatic-Transmission-Cooler/dp/B000CIGE9G

I hadn't had any issues the last 2 winters with it on there. I know on the later 3rd gen 4runners you can monitor tranny temps with a scan gauge or similar device. A fan in front on your aux cooler might be over kill, the factor fan pull enough air through. There are some guys on t4r.org that have gone with a bigger cooler, but the 70268 is the most popular. The bigger you go, the more space it takes on the radiator. Installing isn't overly difficult either.

Does your truck still have the factory radiator? If the radiator has been replaced recently you may not need the cooler, unless you just want to prevent the dreaded milkshake.

Sweet. My truck still has the factory radiator. I want to prevent the milkshake. With 220k on the vehicle, I don't want to push it. The tranny is working just fine, and I want to keep it that way. I imagine a replacement radiator isn't going to be cheap, so the aux cooler sounds great.

 

[SLC97SR5]

I have had great luck with Long, Tru-cool LPD coolers. I have one in my 97 4Runner with a gauge on the transmission output.

My Ford is running 2 of these coolers and they handle the heat.

http://www.amazon.com/gp/aw/d/B005XZXB1M

I have bypassed the radiator on the Toyota altogether to eliminate the possibility of a milkshake.

You definetly want a stacked plate style cooler and you do not need an auxillary fan.

 

[sixstringsteve]

Jon, does your 4runner run cold in the winter? did you bypass the stock cooler?

 

[Marsh99]

Subscribed

 

[jentzschman]

Subscribed

x2, good to know for my next rig. I want an auto, at lest I think I do

 

[sixstringsteve]

I'd trade my auto for a 5-speed and duals in a heartbeat.

 

[jentzschman]

I'd trade my auto for a 5-speed and duals in a heartbeat.

Having the duals is the key though.... Without them, 5spd is kind of pain... Sometimes.

 

[Marsh99]

I'd trade my auto for a 5-speed and duals in a heartbeat.

You should start looking 220k is a lot for a tranny... You might as well fix it before it leaves you stranded.

 

[TurboMinivan]

I'd trade my auto for a 5-speed and duals in a heartbeat.

And I would swap my Jeep's 5-speed for an automatic in that same heartbeat.

 

[Vonski]

Last fall, I installed a stacked plate type (approx. 11"x11") cooler on my '02 Taco and kept it running throught the factory radiator cooler. I have seen no issues, but when its really cold it takes a bit longer to shift for the first mile or so. From my research, a fan on the cooler is overkill.

I also installed a gauge pod pillar recently and will be installing my trans. temp. gauge (finally) in the next month or so, then I'll know what kind fo benefits I'm really getting.

 

[sixstringsteve]

You should start looking 220k is a lot for a tranny... You might as well fix it before it leaves you stranded.

Its not showing any signs of age, I'm going to keep it till it gives me trouble.

 

[Rot Box]

Yes on the gauge. To their credit the stock coolers do a good job of regulating temperature and getting the temp up to an operating level when cold. They also do a good job of failing and causing major damage like you already mentioned :-\ Transmissions don't have a t-stat that I know of so for that reason I would add a gauge. Cheap insurance if nothing else.

 

[Vonski]

Yes on the gauge. To their credit the stock coolers do a good job of regulating temperature and getting the temp up to an operating level when cold. They also do a good job of failing and causing major damage like you already mentioned :-\ Transmissions don't have a t-stat that I know of so for that reason I would add a gauge. Cheap insurance if nothing else.

BTW, unless you're gonna get fancy with a weld-in tranny pan bung for the gauge probe, you'll wanna locate it in-line between the tranny and the inlet to the stock cooler. This will give you the most accurate reading.

FWIW, when weighing factors of cost, quality, and matching the stock gauges, the elec. Autometer Phantom II is the best option I've found.

 

[SLC97SR5]

JoHn, does your 4runner run cold in the winter? did you bypass the stock cooler?

Yes, my 4Runner's transmission will run cold in the winter, I trimmed up a piece of old mudflap to cover the cooler when the temps drop. With the cover in place the transmission will warm up like normal and stabilize around 130-150*.

Initially I ran with an aux cooler and temp gauge plumbed through the radiator and it worked great but I got nervous about the milkshake syndrome. I ran it this way for 5 years.

The benefit of bypassing the radiator is the reduced heat load in the summer. Prior to bypassing it, I saw temps in the 205-215 when pulling Parleys with the A/C on at 75ish mph. Now, the Truck is rock solid at 200-205*f when being worked. Regular driving shows 186-190*f.

I have not observed any drivability or odd shifting from my setup.

The gauge Tee's directly into the output line from the transmission to the cooler so the hottest fluid temps can be monitored.

Another reason I use the Long Tru-Cool LPD line of coolers is this; they are very durable and they have a special "warm up" circuit/passage way built into them. When the fluid is cold and thick it only travels along the upper row of plates, as the fluid warms it is able to travel the entire area of the cooler.

 

[sixstringsteve]

that's great news about the warm-up circuit. I had head about those but I didn't know how they worked. If you ran it without the mudflap in cold temps, would it be cold enough to damage to the tranny?

 

[SLC97SR5]

Also, we are lucky to have a drain plug installed on the Transmission pan. I drain the ATF in the pan every other oil change and my fluid is bright red and smells like new. It is total overkill and you could easily just do it yearly but the transmission holds about 15qts and the pan holds 3qts so you are helping to replensish the friction additives and drain out any heavy particles.

There is only a coarse screen on the VB and a large magnet in the pan. My first fluid change at 76k had lots of fuzzies on the magnet, I have not seen much since then.