Hey Guys,

Just a quick question. My Auto Transmission is pretty modded, VB, DR mod, working on a shift_quick mod (paddle shifter style) (yes I will do a right up on the push up/push down shifting)

An Ive noticed that when I do a good run you can smell the tranny fluid and it gets HOT!!. I have a small tranny cooler on right now but Im going to get a bigger one. also Im getting a tranny temperature gauge so I can watch how hot the fluid gets.

In doing this I jsut realized I have no clue what is normal operating temperature or what is too hot for the 96 maxima auto trans. So I was wondering If anyone knows these numbers, what temp I should try to keep it in and what i should avoiding.

Also I dont want any "get a 5-speed" comments, I want a 5-speed but cant afford it. Just waiting until mine just blows and stops putting up with my driving. then I have the excuse for a swap.

 

WHY ATF WEARS OUT
An automatic transmission creates a lot of internal heat through friction: the friction of the fluid churning inside the torque converter, friction created when the clutch plates engage, and the normal friction created by gears and bearings carrying their loads.


It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the usual temperature range at which most fluids are designed to operate. If fluid temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins to plummet. The problem is even normal driving can push fluid temperatures well beyond safe limits. And once that happens, the trouble begins.


At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, varnish begins to form on internal parts (such as the valve body) which interferes with the operation of the transmission. If the temperature gets above 250 degrees F., rubber seals begin to harden, which leads to leaks and pressure losses. At higher temperatures the transmission begins to slip, which only aggravates overheating even more. Eventually the clutches burn out and the transmission calls it quits. The only way to repair the damage is with an overhaul. As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees F. cuts the life of the fluid in half!


At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, which is commonly encountered in many transmissions, the fluid is only good for about 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and 1,000 to 1,500 miles is about all you'll get before the transmission burns up.

 

I try to keep mine under 200. What really raises the temp is brake torquing if held any longer than 2 or 3 seconds. I launch now at about 1500 RPM which gives me the best 60' times and also keeps the temps down.

I bought the largest B&M cooler I could find and use it only, no connection to the rad at all. The rad may warm the fluid a bit quicker in cold weather but sure doesn't help when its warm until the trans fluid gets hotter than the coolant. Having the trans connected to the rad will also take away from its engine cooling ability. You will get the argument that its better to have the stock cooler in series with the aftermarket one but my experience proves otherwise.

My fluid usually stays below 170 at the track.