Which External Transmission Cooler?

[Xtreme]

Hi All,

As I am having to replace the transmission and cooling system due to a cracked transmission cooler and contamination of both I have decided to run an external transmission cooler and bypass the radiator so this does not happen again. My question is what is recommended for the transmission cooler - fan or no fan.

I am guessing the fan is great for when doing slow speed work, or from when the transmission is working hard but there is not a great deal of air moving over the cooler due to slow momentum - like sand driving.

But will a fan hinder the airflow when towing at highway speeds?

Any thoughts?

[Xtreme]

Also can someone confirm for me which thread I need to have on the cooler?

[FNQGU]

You need to suck it and see...

I ended up fitting a fan, with a switch in the cab to turn it off manually. I have twin PWR coolers fitted front to back and by monitoring the tranny temp I ended up moving the fan from behind the coolers to in front to get best results. If it was a single cooler I am sure it would have only needed a fan behind the cooler, but I was able to reduce it an average of 9 degrees by putting it in front. At Highway speeds I haven't done much testing of the difference as it was too much hassle to keep moving the fan around. I do suspect that behind the cooler would be best though, and this was recommended by NissanNewby as well.

The type of cooler you get can also make a big difference, so do your homework. There is some good reading material on the ARE website about cooler construction.

[jff45]

The ZD30 already has a good sized external trans cooler.

Typically, trans coolers don't have threads. They simply use hoses with hose clamps. There's basically no pressure in there.

[megatexture]

I got pwr cooler suited for 8cylinder cars and plumbed it in after the stock cooler. As jff45 said mine just hose clamped on.

If you want to know direction of flow just turn the car on and hold the hose in two locations and you will feel it heat up as it flows.

[jff45]

In post #41 of my turbo install thread in the DIY section, I included pics of how I moved one of the power steering coolers to the left to make room for a Davies Craig trans cooler.
You can see how I added the new cooler in series with the original.
This is on a TB45E but the ZD30 is very similar.