dgz32

I installed a transmission cooler (bypassing the OE heat exchanger) last year along with a trans temp gauge to monitor temps. Last summer, climbing prolonged steep grades in the North Georgia mountains, I saw temp readings of 210˚+ on two occasions. Trans temps are fine during normal everyday driving. I'm planning an expedition-type trip out west this summer and have no desire to see 210˚ on the journey.

So...I'm looking at replacing my Tru-Cool 4454 (which is 11"x7.5"x.75") with a B&M unit (70264) that is 1.5" shorter but twice as thick (11"x6"x1.5"). I could also go with their universal cooler (70266) at 11"x8"x1.5", which looks like a great option, but does not have the bypass.

Another option would be to install a fan on my existing cooler but would need to mount it elsewhere to fit the fan as a puller type. Not sure if this is a better idea than just going with a thicker cooler.

Any help or advice with any of this is greatly appreciated.
|dg

kball

You didn't mention the temp but I would think summer heat in Georgia is well.. hot. To me, seeing 210 in prolonged uphill climbing during summer doesn't seem "that" bad. Knowing that Toyota designed these using a skimpy little cooler in the radiator that probably never saw a temp less than IDK, 140? I'm sure during the summer the bottom of the radiator doesn't even get close to that low but I could be totally talking out of my rear. I'm just saying it seems like Toyota didn't put a lot of emphasis on cooling. These transmissions still last for hundreds of thousands of miles. My .02, put synthetic in the trans and call it good. According to the chart Mt. Goat posted in the "bypass" thread, the synthetic can handle way over 210.

dgz32

Thanks. I saw that chart, too. I've been wanting to go synthetic for all gear oils, but it's had conventional in it it's entire life. Guess I could get a 'mix-friendly' synthetic and do several drain and refills.

On another thread FOG brought up that it could also be the fan clutch. Mine's due, so I'm gonna start with that...

|dg

85 PICKUP

Arent all syn's mix friendly? I went with the Valvoline Maxlife ATF when I did my drain and fill and didnt realize until later that it was a syn fluid. Posted a similar question on Bob is the Oil Guy forum and was told that mixing the Maxlife fluid was just fine.

J2F42C

I've been fishing in the Chattahoochee National Forest near the Fairgrounds and it can get hot there. If you do not want to go the way of buying another radiator and using the radiator cooler in-line with the 4454, I'd say you have two options:

Keep the 4454 and buy an external puller fan plus a fan harness kit. I would imagine a 6.5" fan would fit just fine, you may be able to squeeze a 7.5 on the cooler. Check out www.spalusa.com as well as models from flex a lite and derale. Wiring instuctions are provided in pdf format if wiring is not your thing.
I think Mt. Goat has used/is using a Spal on his so use the search engine to see if you can locate his pics of it.

Buy another cooler such as the B&M 70264 or check out the Tru Cool 4544 or 4589. A friend has the 4544 and while it does cool well, IMHO, it blocks too much of the A/C condensor.

Also check the clutch like Fog said and put in some good ATF like Valvoline MaxLife ATF.

dgz32

Thanks, good to know!

Thanks. Yeah, it can get very hot here in late July - August. I don't remember the exact temps but it was in the 90's. It'll get much hotter than that in AZ.

I saw Mt. Goat's set up with the Spal, but am not too keen on relocating the cooler for a puller fan right now...not that it's a huge deal. I've pretty much decided to do synthetic for transmission (and front/rear diffs), along with fan clutch replacement, and the thicker B&M cooler.

|dg

LINY4Runner

I've read that most of the B&M coolers have bypasses, but a different method than the TruCool uses. I just ordered a B&M 70255.

http://www.bmracing.com/SPECIALS/Aut...U-11x5-3-4x3-4

BajaRunner

Any room for mounting a smaller unit in series with the current True Flow?