I hit 240 F!

[sethc24]

I was shuttling mountain bikes up a local logging road and my transmission hit almost 250 F on it. Is this damaging for my transmission?

[Red '97]

sounds hot to me... how long was it like that?

[7.3Lariat]

Originally Posted by sethc24

I was shuttling mountain bikes up a local logging road and my transmission hit almost 250 F on it. Is this damaging for my transmission?

It certainly isnt good. Do you know how long you were pushing 200+? Definitely need to get either a 6uhoh cooler or an inline aftermarket one to prevent that.

[Demo250]

Shuttling bikes you say? Sorry to change the subject, just thought it was cool to see another rider in the 7.3 section. What kinda bike you got? This is my current ride.

[NCHornet]

Yeah, 230 is to hot and damage was being done. If you are lucky the only damage will be to the fluid which I would be changing or at least send a sample to Blackstone. But now you have to ask why did it spike this high? My guess is your bypass line is stuck part of the way, or all the way open. Look on the pass side of the trans, you will see two metallic lines coming out of the trans. The front line is going to the trans cooler and the rear is coming back from the cooler. You will also see a line at the trans that coneects the front and rear lines. This is your bypass line, if enough pressure is sensed on the front line the valve will open and the fluid will flow back into the trans without going through the cooler. These pressure valves can fail and your temps spike because the fluid isn't being cooled through the cooler. Easy way to tell if this is your issue is get the trans up to normal temp, grab the bypass line with your bare hand. If it is to hot to grab you have a bad bypass valve. The valve and line are easy to replace for around $60. Dieselsite also sells a kit to eliminate this line, but I don't recommend using it.
If you are wanting to have increased trans cooling most will say to use the 6.0 cooler. This is a great recommendation, my temps have dropped a solid 40 degrees after installing my 6.0 cooler many years ago before it was the " mod to do" . But before the 6.0 cooler the thing to do is use the cooler out of the V10. It is between the 7.3 cooler and the 6.0 and it provides enough cooling to work for 98% of the users. I use to get stacks of the 6.0 coolers new in the box for $60 each back in 04 when the recalss were going on and every Ford dealer had stacks of these coolers laying around. But not any more, they now fetch a tidy sum now.
If I were you I would first figure out what caused your temps to spike. My bet is bypass line, but could be a bad gauge, bad ground or other issue. Then do a complete trans fluid flush. I have posted the " how to" on here multiple times. If you can't find it any where PM me and I will send it to you. Bottom line is you should be happy you had the proper gauges to monitor these temps.
Later

[rufushusky]

Originally Posted by sethc24

I was shuttling mountain bikes up a local logging road and my transmission hit almost 250 F on it. Is this damaging for my transmission?

What fluid are you running? A dino fluid will start to fail at that point over prolonged period of time. That being said 5 minutes at 240 isn't the end of the world. Really your best bet is to do a cooler line flush, get a 6.0, V-10 or tru-cool cooler and next time you use a logging road...use a lower gear.

I have pegged my trans gauge at 250* on my dodge and it still made it 176k before giving up the ghost. My father's 4R100 has seen 325* and somehow is still going.

[sethc24]

It was at 245 F for less than 5 minutes. This is the first time its got this hot.
I was climbing in the "street tune" from tdp so maybey its too agressive for it. I will try a different tune. It usually hits 195-200F on the same logging road.
I changed the filter and trans fluid about 2000 km ago so i am not too worried about it.


As for my bike. I got a 2004? santa cruz bullet. Fifth element rear shock ( old i know.) Fox 36 talas on the front. Its an older bike but its been great.

[rufushusky]

Originally Posted by sethc24

It was at 245 F for less than 5 minutes. This is the first time its got this hot.
I was climbing in the "street tune" from tdp so maybey its too agressive for it. I will try a different tune. It usually hits 195-200F on the same logging road.
I changed the filter and trans fluid about 2000 km ago so i am not too worried about it.

Hmm...sounds a like a bigger cooler would be a good idea for you. Really I would at least do a UOA on the ATF to make sure it isn't too toasted but that my humble opinion.

[sethc24]

Mmm well i pulled the dipstick and it looks a nice pink not burnt and it doesnt smell burnt. Yes i need to get a bigger cooler. Honestly what was ford thinking.

[rufushusky]

Originally Posted by sethc24

Mmm well i pulled the dipstick and it looks a nice pink not burnt and it doesnt smell burnt. Yes i need to get a bigger cooler. Honestly what was ford thinking.

It is all about the margin to Ford on that one!

What are you running for fluid? What brand and grade(dex/merc vs. Merc V) etc etc?