SO, I got a little carried away hauling oak firwood up out of this river canyon. My trans temp gague pegged at 250*+ for 2-3 minutes measured from the output line to the cooler. I have a second sensor in the pan that never got above 180*. Double deep pan on a 2001 w/120k miles.

Should I dump the fluid or are those reading no big deal? I tend to baby my tranny. I have seen trucks with a cab-over and horse trailer pull that same grade. God only know what that would do to a stock auto...


Thanks for any advice.

 

I have seen the same temps for about the same length of time.... backing a camper up a steep driveway.
I kept a close watch on my fluid for two weeks (on the dipstick). Looking for dark color or burnt smell. Found none.

I just bumped up my routine change interval a bit, when the time came.

If you didn't get CEL..... I'd say no worries, mate!

RJ

 

Change it. Fluid is cheap!

You can have fluid that is sheared and ineffective without any discoloration or scent. These are not accurate ways to determine if you need a change!!

Dave

 

If by sheared, you mean split long chain carbon molecules.... it's unlikely. Don't really see how shearing can apply.
And heat is not a primary cause of shearing... at least not 250*
Actually, ATF is one product that will show any deterioration by feel and smell. I agree with you on the color, though.
I meant to say wipe the dip stick off with your fingers and feel for anything less than good clean oil feel.
If 'Kayak' did damage, it will show up in near time and on the dipstick.

Above is just my professional opinion from working last 20 yrs in a company that blends high grade lubricants, including ATF.

Of course, changing the fluid is always an option. Not a cheap one in my book, but compared to replacing a tranny, I get your meaning.

RJ

 

If temp light never came on, it is still good to go. If still bright red is not damaged and only suggestion is shorten your normal service interval some.
Shearing - I don't think so.

 

Shearing is very real in trans fluid.

But to each their own.

Dave

 

Thanks for the advice! I run Mopar ATF 4+ with the double deep pan, your talking $60 or more to change it. I change it once a year even though 4+ has a "fill and forget" long life rating. I would not be suprised if the fluid I'm running only has 20k miles on it.

I have read a ton on the subject over the years and never know what to take of the tempature limits. I know the fluid leaving the TC was over 250* for less than 5 minutes while the fluid in the pan never got above 180*. So take the below quote - do you read this as saying if the fluid ever reaches 220 the life is reduced to 25k miles... or.. you can run the fluid for 25k miles at 220*?

"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 have also hear many times "if the idiot trans over heat light ever comes on you have already destroyed the tranny".

 

I like your sig, lets see some pics of that truck

 

Not mush to see. Just a garden variety truck!

Here's a couple of shot's from forever ago.

Third Gen brakes


Third Gen brakes inside 3rd Gen wheels


Rear shot


Twin install


Cam install


Monkey butt




Dave

 

Those general figures are arrived at by sustained testing at higher temps and then analysing the fluid. It's sustained wear and tear.
So, short burst at high temps, while not great, are not what they are talking about. if you ran 250* for 1 hr+, I'd be concerned.
To repeat myself.... if it feels close to new, and no bad (burnt) smells, your OK, IMPO.

RJ

 

Gerat information, thanks! I checked the fluid and it looks new, checked my log book and I have 4,000 miles since the last change back in Oct. of 2008. I will rest easy, no way I will change it with that few miles on it.

4,000 miles in 10 months. Had no idea I was driving it that little. All due to taking up motorcycle commuting when diesel prices peaked.

 

Corrrect decision. At sustained 220 degrees the life is 25K miles. When +4 was introcuced, the engineers used new technology additives that were engineered to survive 350 degrees. The additives have proved effective in extending fluid change intervals on "normal" service uses to 'lifetime fluid" in some cases.