avengermike

hey everyone i wa woundering what the norm temp is on a auto trans in a 4x4 96' drw 12v? and whats the hotest i want it to get?
thanks for any help

jrs_dodge_diesel

My tranny, while cruising with ambient temps @ 85°F, usually sees temps ~150-160°F. My sensor is in the hot fluid line coming from the tranny going to the cooler. Highest I've seen it go was in stop and go traffic and it went up to 195°.

As far as critical temps go, you should start getting worried at 210°. At that point you should pull off the road, shift to NEUTRAL and increase engine RPMs to 1200-1500 RPMs to pump more fluid through the tranny coolers. 220° and above can start the additives breaking down, reducing the fluid capability to protect the tranny. Above 250° and you'll start having problems with increased wear, especially on clutch paks. Above 275° your fluid will have a severely degraded service life and will smell burnt.

Hope this helps you.

macattack_ga

Thanks jrs_dodge_diesel,

So if I'm in the 200+ range just lightly tooling around town w/ no load (kinda hilly town) what kind of problem do I have?

It seems to shift fine for an unmodified auto...

TIA

Don Baggett

Do you have the sensor probe in the hot line? Have you checked your fluid level?

jrs_dodge_diesel

If your sensor is in the hot line, that could indicate that your tranny coolers are not working up to snuff. Or low fluid too.

macattack_ga

probe is in the hot line.
I've checked the fluid... but I'll double check it... could this be an indication that the bands need adjustment?

kd460

Probably normal. Maybe slightly higher. Most the heat is generated from th torque converter. What does it do when you get it on the open road?

Lots of shifting/downshifting and stop and go will get the heat up there. KD

jrs_dodge_diesel

Check the tranny cooler up front and see if its plugged with dirt/mud/oily gunk, and for bent fins.

Crimedog

I used to see hight temps when I plowed snow, 250 was hit a couple of times, but only for short intervals. When I got my new tranny I asked Dave about tranny temps. He said with a probe in the hot line that you don't have to worry until about 250, then you want to alter the driving to cool things down. I remember doing a steep hill driveway in 4HI and by the time I was done my gauge was well past 250, after I got home that night I looked at the fluid and smelled it. It was still nice and pink and smelled normal. You don't want to continuously sustain 250, but it is Ok to hit once in a while IMO, because by the time it gets back through the cooler it is cooled quite a bit. Since you are in a hilly environment your torque converter is going to be making a lot of heat, that is why you are seeing high temps. If you can run with overdrive locked out so that the torque converter will lock up you will see your temps drop substantially. I see about 150 running around town, with the TC locked on the highway I am barely over 100.

macattack_ga

on the road it's just under 180. it cools off quick when the TC locks.
Thanks

kd460

I've always been told/read that a good general guide is 100 degrees OVER outside temps is considered "bout right". KD

jrs_dodge_diesel

60-80° above ambient air temp is more accurate if your sensor is in the hot line. It depends on how hard you're working it and how well / clean your tranny cooler is.