I'm planning to do some towing, and in my past (non-Subaru) cars I always added an auxiliary transmission oil cooler, preferrably one offered by the manufacturer.

I've found that Subaru offers one, p/n D551SXA000, but it's listed only for the Tribeca. It's claimed to increase towing capacity from 3,000 to 3,500 lbs.

 

I don't plan to exceed the 3.6 Outback's towing limit of 3,000 lbs, but for the sake of transmission longevity (because I tow a camper on vacation, and because I will live in the Cascade Mtns which itself is hard on transmissions), I want to know what I can do to prolong the lifespan of the drivetrain. So has anyone adapted this Tribeca cooler to their 3.6/6-cyl Outback? The engine and transmission is basically the same, isn't it?

 

And regardless of whether you installed that particular cooler, have any of you installed any auxiliary cooler?

 

Thanks, in advance.

Edited September 9, 201213 yr by Ken C

It's done all the time. Change AT fluid every 30,000 miles and install a cooler.

 

I would get an aftermarket cooler, they are very simplistic, there is nothing to them that warrants getting it from Subaru. Though I can see the attraction if it offers installing aids given that it's for a Subaru, though I doubt that's the case. The aftermarket solutions are fine if installed properly.

 

What you should be considering if you are really serious about adding value and protection over the long term are ATF temperature gauge and/or thermostat/bypass set ups. The ATF gauge will be the only thing that verifies your fluid isn't cooking your trans. Proper operating temperatures can be googled but 180-200 i think is somewhere close. And too much cooling can result in poor cold weather performance depending how much it's cooling and how cold it gets where you live...though I don't suspect NJ to be too cool that it'll give you poor shifting in the winter due to fluid not reaching nominal operating temperatures. The bypass/thermostat allows it to maintain a temperature (just like your engine) rather than get too hot or too cool.

you can opt for the u-haul heavy duty model. generally you have the fluid coming back from the trans go to the cooler first, then through the radiator and it enters the trans at mean operating temp.