This is more of a drivetrain question (but I didn't know where to post this topic in the forum)...

I've seen kits for transmission coolers and differential coolers. These kits usually include your basic "cooler", an oil pump, hoses and fittings, a relay, etc.

My question is this. How would you determine the ideal operating temperature for your transmission and differential (or at least, the ideal FLUID temperature)?

We all know that if the fluid gets too "hot",...this is a problem. (Lack of lubrication, etc.)

Also, if the fluid gets too "cold",...this is also a problem. (Lack of proper fluid flow, decreased transmission life, etc.)

In the stock condition for RX-7s (and most cars), there are no tranny or differential coolers. So, technically speaking,...all cars tend to run in the "hot" side. I'm sure all of these cars can benefit w/ some sort of cooling.

And while adding a thicker/heavier weight fluid may be ONE answer,...I would also like to be able to figure out a way to calculate the "ideal" operating temperature for the fluid in a transmission or a differential.

I mean, in endurance racing,...ASSUMING that you are not able to change out the fluids in your vehicle,...you must rely on the transmission and differential coolers to keep the fluids operating at their "ideal" temperatures. In this type of environment, you are testing the ability of the fluid to lubricate while also testing the "life" of the fluid itself. If either one of these were to "fail",...you would be screwed.

So my question remains,...how would you determine the "ideal" operating temperature for the fluid in your transmission and differential?

 

Ask the manufacturer...............

 

Wow, that thread ended quickly

 

Seriously. I thought I would get some sort of response from this thread.

 

I for one can't say what the answer is. I would go the route of speaking with the fluid manufacturer though. The coolers aren't there to cool the gears and metal, they're there to keep the fluid from overheating. The fluid manufacturer will know what the operating temps are, and the operating temps of the fluid are what's important regardless of what it is lubricating.