Advice for buying a transmission cooler

[tcbarnard70]

Hi all! I'm very happy to be a newbie here on this site.

I recently bought a 2001 4Runner SR5 with 152,000 miles on it, primarily for the purpose of towing our pop-up camper (a 2006 Forest River Flagstaff). We live in Colorado and so mountain towing will be in the plans. In doing research, I've learned that a transmission cooler for this type of towing is a must so I will be installing one soon. I've found in my research, however, that there seem to be a couple different ways people install the coolers:

1) Running the lines directly to and from the transmission to the cooler;
2) Disconnecting only the radiator line returning to the tranny and tapping into that line with the tranny cooler.

I have two questions:

1) Which of the above is correct?
2) Do tranny coolers have ratings to tell what size I should buy based on my towing weight? So far, I haven't seen any differences in specs, at least without digging further.

Thanks for your help!

Terry
Westminster, CO

 

[Jon]

The purpose of the external trans cooler on this truck is to separate the trans cooling system from the engine cooling system. If radiator failure occurs (like mine did) you end up with a trans full of boiling antifreeze.:ybrick: Hence why I now have a 5spd!

But back on track, for a short period after the pink milkshake and a few flushes, I ran the B&M 70264 cooler. Good product with a good price.

Here ya go http://www.toyota-4runner.org/3rd-gen-t4rs/88642-sweet-strawberry-milkshake-fml.html

 

[Moves2Music]

I have mine hooked up completely separate. Trans to cooler, cooler to trans.
Everyone will have a different view on how to hook this up.

Most people will say b&m, trd or trucool. I have a trucool. There are several threads on trans coolers and how people have hooked them up.
If you search this forum or even throw it into a google search, tons will come up.

 

[tcbarnard70]

What confused me was that I couldn't see how to avoid the pink milkshake while running the trans cooler in series with the radiator. I would prefer to just bypass the rad altogether. Do you have any issues with the tranny taking longer to warm up (and affecting the shifting) using only the trans cooler?

:hello:

 

[Drcoffee]

you live in Colorado so because you will be running up and down the mountain roads, consider using two coolers in series because one trans cooler won't be sufficient. Plan on an extra gauge to monitor the trans temps and be willing to sit on the roadside if the temps rise too high. Plan on covering one of the coolers in the winter to prevent overcooling when temps drop below freezing.

Or just buy a new radiator $120 and add the cooler $60 in series and forget about it.

:redbrick:

fun reading. you decide

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

 

[Steve240]

^ haha I was just thinking here we go again...

 

[4ever4running]

Definitely go with option 1 and run the transmission lines to and from the external transmission cooler to avoid the pink milkshake.

I am running B&M 70268 transmission cooler which has slightly more cooling power than the other models that most guys are running. I decided on the 70268 because I was going to be towing a full Uhaul trailer from Albuquerque, New Mexico to Washington, D.C. and I wanted to make sure that I had enough cooling power to keep everything in functioning properly during the 3 long days of driving. I must say that I am very impressed with the 70268 and I never had any issues with overheating at all. The temperature remained between 180 and 210 degrees for most of the road trip. There were times that the temperature spiked to around 240 degrees when going up through the mountain pass leaving Albuquerque and heading up the Shenandoah valley, but even that isn't too bad considering that the stock transmission temperature warning light doesn't come on until the temperature is over 300 degrees (or so I've heard...).

I was was also worried that the 70268 would be too much cooling power when the weather is cold so I added a thermal bypass. The thermal bypass senses the temperature of the transmission fluid leaving the transmission and has a valve that automatically adjusts and either returns the fluid to the transmission without passing through the cooler or sends fluid through the cooler. This allows the transmission to warm up much faster in cold weather because either a small amount of fluid or none at all is acutally passing through the cooler. The valve adjusts automatically and is not fully open until the transmission reaches an optimum operating temperature of 180 degrees. Here is a link to the thermal bypass that I went with: Transmission Parts Cooler Service Products Remote external thermal bypass. I hope this helps!

 

[tcbarnard70]

Thank you all for the advice and ideas. I have several options, it seems. I appreciate it!

I like the thermal by-pass idea. I thought about installing a valve that I could switch in the winter to allow the trans fluid to pass through the radiator and back in the summer to by-pass it. But this would do it automatically. I haven't decided exactly what I'm going to do yet but I still have some time.

 

[tcbarnard70]

So I just went and read through the 9 pages of thread regarding this topic that occurred earlier. It pretty much answered any question I ever had about the topic. Thanks again for passing it along.