Automatic transmission fluid cooler

Hey everyone, i'm looking to be doing some towing with my ATX protege5. I've got a hitch coming in and i'm going to be renting a uhaul 4x7 flat trailer to tow a dirt bike, so not too much weight and i won't be going more than a 100km's 1 way. After doing a bit of reading, i know that the atx pros have a fluid cooler stock. I am just wondering now if i should get an aftermarket cooler as well to help with cooling. also, to my knowledge that car still hasn't had a fluid change done. it's at 150,000km's and i've had it since 100,000. my mech said the last time i was in (at 145,000) that the fluid is still good and shouldn't worry about changing yet.

What are your thoughts one this, should i worry about getting a cooler and changing fluid, or keep going stock? Any suggestions would be greatly appreciated.

I changed my radiator awhile back. If I recall, there are two small hose barbs at the bottom of the radiator which were the input and output connections to cool the ATX fluid. If you get an aftermarket cooler. it would be relatively easy to disconnect the radiator connections and put them into the ATX cooler.

Transmission fluid usually does look good till it's long past time to change it. (I've often seen cars with 30k mile fluid change intervals look nice and red at 90k). Appearance doesn't denote chemistry.

Yes, the in-radiator cooler is stock. They're usually on the cold-side of the radiator to cool the fluid without over-cooling it. If you want to go with an aftermarket cooler, plumb it in line with and before the factory cooler. You don't want the ATF too cold (standalone- or post-factory-installed) or it doesn't work right (viscosity, cook off water, etc).

With that many miles on the fluid you're as likely to find problems from changing it as you are to roast the trans towing. Just keep the speed and acceleration low. That size trailer and little dirt bike aren't much more drag than a few friends and a weekend of luggage except tire and wind resistance.

Make sure the trailer tires are aired up!!! I rented the biggest enclosed trailer for my little toyota pickup to pull (and loaded it to the tits and beyond...~6klbs pulled by my little 2800lb 115hp truck ) and they had the tires at like 35 psi (rated for 65)

If the trailer has attached ramps, fold them flat somehow. Even if they're mesh or crossbars, they might as well be a canvas sail at speed.