The reason i have a question about this I have a cooler now that has the steering cooler and engine oil cooler all in one. If I do away with the steering cooler i can put a larger oil cooler in. Space limit.

if you're having oil temp issues then change it out to a single cooler, if not Id just leave it alone

On a long wide open oil temp will go to 260* +. I have never let it get any higher. I am thinking about installing a larger cooler.

I didnt want the interruptions in engine cooling or potential blockages. You can use a small transmission cooler with an electric fan and put it off to the side under the gunwhale. At that point you can put it on a switch or do a thermostatic heat switch (Derale inline fan thermostat)

Not saying anyone need or doesn’t need a ps cooler. Just adding more info below:

Mercruiser’s small blocks have no engine oil coolers but have ps coolers. They are short and wide open inside. Nothing can get stuck in the water passage. Ie: can’t block water flow.

i’ve relaced a ton of Chevrolet pick up and Suburban ps coolers. Things corrode up here in the land if overly salted roads.

Below is merc style ps cooler.

175 to 220 degrees
The optimal temperature range for transmission fluid is 175 to 220 degrees. Above that, for every 20 degrees bad things happen, starting with formation of varnish at 240 degrees, followed by seals hardening, plates slipping, seals and clutches burn out, carbon is formed, and, ultimately, failure.

Mine never gets hotter than 170-175*

oh oh I`m not evaporating the moisture, I better get a power steering heater

I have a used small ps cooler if you want to go that route

I was wondering this same thing about the need for a PS cooler. If you have hydraulic steering (rams outside the boat) I would think they almost act as a cooler themselves???

I think the heat build up is from long straight running minimal turning. Not sure on the rams as there out of the water while on plane. People thought I was nuts when I ran twins without oil coolers but never needed them and did not come on the boat originally. Although did have power steering cooler. Not to say it was necessary though.

when the boats running and not turning the fluid goes from the pump to the helm then back to the reservoir, only when turning is the helm sending fluid to and from the rams, the helm is a valve that directs fluid........I think I got that right........