Transmission Temperature - 2009 T&C

Well I think we're good. Transmission Temp was 150-175 normal driving and only hit 190 after 10 minutes of steep up hills. Feeling pretty good about that.

Thomson7 wrote:
I wish I'd gone that route now. Would have been cheaper in the long run!

If you're talking about the Scangauge2, don't fret - it may not work for your vehicle, so you may have gone the correct route.

There are a limited number of Chrysler products it will read. I tested the codes for them, and mine is one that it does indeed work with.

Turtle n Peeps wrote:

jrw1550 wrote:
Goldstalker and Mark you both gave an answer but did not provide anything to support it. Why was it comical and why does it not apply for modern transmissions. I am under the impression that heat is the number one enemy of transmissions. do the modern ones do something different in that regards. A little more information would be most helpful. Thank you.

#1. ATF is night and day difference from what it was in the 60's.

#2. Seals are made out of waaaaaaaaaaaaaaaay better material than years ago.

#3. Coolers are huge now days.

#4. Tranny's lock up 1 to 1 now days to keep heat down.

#5. It is just some chart apparently made by someone selling transmission coolers!

Refer to your owners manual for what is acceptable for your vehicle, not some chart made by some guy on the internet trying to sell you something!

BTW, thanks for the insight as you your engineering experiences, Mark. Very informative!

I wish I'd gone that route now. Would have been cheaper in the long run!

jrw1550 wrote:
Goldstalker and Mark you both gave an answer but did not provide anything to support it. Why was it comical and why does it not apply for modern transmissions. I am under the impression that heat is the number one enemy of transmissions. do the modern ones do something different in that regards. A little more information would be most helpful. Thank you.

Materials used to construct automatic transmissions have been greatly improved since the 60's when that chart may have been somewhat accurate. ATFs especially only resemble their predecessors in that both are red. Modern ATFs can run as hot as 220°F all day and all night long and still last longer than earlier fluids that stayed at 150°F. I've tested modern ATFs over 300°F and they didn't burn up like that chart implies. That doesn't mean I recommend running your trans that hot, but doing it won't kill it.

I've seen a test transmission that ran VERY hot, but didn't fail. The gauge we had only went to 320°F, but solder melted out of the solenoids. The solder that was used to construct those solenoids had a melting point of 450°F. So we know it got at least that hot, maybe hotter. The trans still worked and the fluid was not destroyed, but definitely showed some discoloration from the heat.

jrw1550 wrote:
Goldstalker and Mark you both gave an answer but did not provide anything to support it. Why was it comical and why does it not apply for modern transmissions. I am under the impression that heat is the number one enemy of transmissions. do the modern ones do something different in that regards. A little more information would be most helpful. Thank you.

Read Mark's signature. "Former transmission engineer". From reading his posts over the years, he clearly knows what he is talking about when it comes to transmissions. I'd take what he says at face value, though I'll agree more of an explanation would be helpful to educate the rest of us. :B

Thomson7 wrote:
ib516, when you plug the scan gauge in, does it not put the computer in a sort of diagnostic mode? I thought that was part of the problem with using those sorts of systems to monitor performance... the vehicle doesn't enter a "normal" condition.

Nope, the ecm has that data in the can bus data stream anytime the truck is running. All the Scangauge does is passively read it.

Typically 100 degrees above ambient temperature is normal operation.

jrw1550 wrote:
Goldstalker and Mark you both gave an answer but did not provide anything to support it. Why was it comical and why does it not apply for modern transmissions. I am under the impression that heat is the number one enemy of transmissions. do the modern ones do something different in that regards. A little more information would be most helpful. Thank you.

#1. ATF is night and day difference from what it was in the 60's.

#2. Seals are made out of waaaaaaaaaaaaaaaay better material than years ago.

#3. Coolers are huge now days.

#4. Tranny's lock up 1 to 1 now days to keep heat down.

ib516, when you plug the scan gauge in, does it not put the computer in a sort of diagnostic mode? I thought that was part of the problem with using those sorts of systems to monitor performance... the vehicle doesn't enter a "normal" condition.