Transmission Cooler

[Nick V]

I recently had the ATF temp light come on when towing, and having just had the chance to get under the truck I know why.

The only transmission cooling I have is from an auxillary cooler which was installed before I had the truck, as the bottom of the rad has no inlet/outlets for this ( I assume a manual rad!). The other issue is that the trans cooler is almost lying on the bash plate therefore getting next to no air flow!!!!

I need to sort this so my question is, that if I use the stand alone cooler and just reposition it into the airflow, will I cause any problems to the box by over cooling - if that's possible?

I've done a search but opinions have varied in the past! I personally don't see how I can cause damage, but there are people on here with better knowledge of these boxes than I have.

Cheers, Nick

[tweak'e]

fit a thermostat on the trans lines. that will let the trans warm up.
otherwise you can get it to cold if its snowing etc.

if you can't get a thermostat then pack the cooler out a bit so it gets some airflow (but not a lot) and use a thermo fan. so fan only come on when trans starts getting hot.

[Bogus]

You could fit a 3/8th thermostat if overcooling is a concern,

http://www.flexolite.co.uk/pdf/Oil%2...components.pdf

I have one fitted in my stand alone tranny cooler set up. I,ll let others answer if overcooling is a concern as I'm really not sure.
I do know that when the transmission is in lock up and your whistling along at 60ish or more on a balmy Scottish day,( 16-17deg) even with a stat and nothing passing through the cooler, tranny temps are low ( 40 ish) Thats probably why Mr Toyota put the heat exchanger that we call the tranny cooler in the rad.
I don't do a whole lot of that kind of driving however so the odd occasion when temps are low don't cause me concern.

[Nick V]

Thanks for the info chaps, very helpful

Cheers, Nick

[TonyN]

I've never needed a stat, its a little overkill in the UK IMHO, but by all means fit one.

Mount the cooler behind the bumper, so you get airflow from the vents under the metal top part, fitting a square number plate makes things better too.

You may need a bigger cooler if you don't use the in rad cooler at all.

I've always used an average size B&M Supercooler, and no in-rad one, and never had a AT Temp light on even when towing silly heavy trailers. The usual aux coolers might not cut it, especially where you have it mounted. Try it behind the bumper and see what happens next time.

[Nick V]

Thanks Tony, that's reassuring. I'm gonna move the cooler tomorrow to that position. As I said, it's laid on the bash plate and it's fairly large almost covering the bash plate! (I never fitted it, but it's been there since I purchased the truck 6 years ago). Should be towing again Saturday, so will see what happens.

Cheers, Nick