Transmission cooler questions

There are a lot of threads here on installing ATF coolers and in every one I see the cooler is mounted with the cooler passages going vertically. I was going to mount mine horizontally since the radiator passages run horizontally, it seemed like I should follow suit. I’m sure whoever designed the radiator knew more about heat transfer that I do.

Is there a reason for mounting them vertically or is that just for better fitment?

Should i be concerned about drawing air through the transmission or should I try to fill the cooler with ATF before initial startup?

Am I (typically for me) obsessing over nothing?

 

Does not matter how the cooler is oriented. Many choose to bypass the radiator trans cooler because of the fear of pink milkshake

 

I’ve seen that bypass done too but I plan on installing the cooler in series with the radiator, out from the radiator, into the external cooler then back to the transmission.

 

Also what I did, but I added a remote filter into the mix as well. My order is out from the trans into the factory radiator 'cooler', out from that into my cooler, out from that into the remote filter, and finally out from that back into the trans. Been this way for about four-five years without issue. I change the remote trans filter ~once a year. You can see the remote filter mounted on the 'cool' side of my intake heat shield.

 

If that denso radiator fails.....which I've never heard of.......it could ruin your transmission.

If anything I'd forego the rad altogether and just go little larger add on cooler.

Advance auto had em in all shapes and sizes....
they had one slim enough to sandwich between hood release mount, and ac coil...
double the size of the one when I bought the truck.......
gave me a chance to change the hoses out which are suppose to be done every 5 yrs......
Hot hydraulic fluids eat hoses from inside out......chunks of dissolving rubber floating around and what not......

 

In the end I bypassed the radiator's built-in tranny cooler altogether

 

I can't cite a specific source other than what I recall reading from @gearcruncher (in from the bottom barb, out through the top). I personally have the cooler on its 'side' and after the radiator. So flow is into the radiator cooler ---> Hayden cooler ---> out to transmission.

 

Did you relocate the horn of just delete it?

 

I had previously relocated the horn since I was going to use @zero4's location/method but ended up using the Hayden mounts because it (the cooler) was sticking out a little too far using the aluminum L bar and contacting the ARB bumper.

 

The ATF lines going into the radiator/heat exchanger is not only a cooler but it also brings the ATF temp up quicker. If you live in a cold climate area it may not be a good idea to bypass.

Ever notice how your trans shifts (harder & delayed) when it's not warmed up yet? I live in hot SoCal but even on some winter mornings it takes a while for the trans oil to get up to operating temp. I have my trans cooler after the stock heat exchanger.

 

That is an excellent point.....for those of us that have by-passed the radiatior....
It would be a good ideal to let it run for minute or two.......and longer if northerly....

I have a new engine.....it'll run forever.....its the tranny I have to baby now........

 

I think this orientation is the best way to prevent air from getting trapped in the system

 

That pump is pretty ferocious, it'll flush in any orientation....
trust me....

 

That's the thing, with the radiator bypassed the trans oil won't get up to temp just sitting idle, trans gotta be under some load. Sitting idle for long periods of time ain't good for gas engines either.

When you notice the trans having delayed shifting, just don't run it hard until it gets up to temp. I forget (doesn't get cold here much) but when my trans temp is under 100° or so that's when it shifts funny.

I thought about bypassing too when I installed mine then changed my mind even though I live in hot SoCal. It's been a few years since I've towed anything but even on hot 100°+ days my trans temp never gets over 200° (going up steep hills) but I'm also running a 76°/170° tstat (Corolla 1ZZ-FE), stock is 84°/180°.

 

Whats the trans temp number i should pullover and let idle till it cools down? 240degrees?

 

It'll heat faster than you think with that pump going full blast.....

I'm a retiree, I'm comfortable with little idle time, and drive it slow 1st couple miles.....
Further combat with keeping fresh fluid in it.

About every 6mo.....I suck two quarts out.....and two back in.....

What if your engine overheats.....does this destroy the trannsmission too...
I'm not a fan of adding more failure points to a system......

Does this mean people far north are destroying their steering racks.....

 

I believe up to 220 is still ok. If you get close to 240 should probably let it cool down a bit & if you consistently get that high plan to change your ATF sooner than usual.

 

Curious, what kind of temps are you seeing with the radiator bypassed (ATF vs ambient)?

 

Have a 98 .....will that show up on a scanner.....
I know you get coolant and air......

 

Also think its a good ideal to dump the toyota and switch to maxlife atf before its too late and tranny is too old....
And swap two quarts every other oil change....
Forget the rock catcher screen, forever....and instead do the mag in-line filter....every 30K....

In these old girls....deteriorating hoses are your no.1 source of internal contamination....

Close second is vac leak problems........again rotting hoses.....