trans temp
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Mountain Pass
Joined: Mar 2006
Posts: 101
Likes: 1
From: Dayton
trans temp
I am asking this for my grandfather he has a 2000 f-250 with the 5.3L diesel and I am not sure what trans gets paired up with it, but he is wanting to know what the trans temp should be running normally. Thanks for the help.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,696
Likes: 2,618
From: SE Florida
Yes, that's right, and there's nothing wrong with that.
The maximum short term (less than 1/2 hour) temp is 250F. The maximum sustained temp is 220F.
If the trans goes over 220F for more than 1/2 hour, or ever hits 250F, find a safe place to stop and idle the truck in park or neutral. NEVER shut the engine off when the trans is really hot.
The maximum short term (less than 1/2 hour) temp is 250F. The maximum sustained temp is 220F.
If the trans goes over 220F for more than 1/2 hour, or ever hits 250F, find a safe place to stop and idle the truck in park or neutral. NEVER shut the engine off when the trans is really hot.
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Elder User
Joined: Feb 2004
Posts: 772
Likes: 3
From: Mount Airy, MD
Yes, that's right, and there's nothing wrong with that.
The maximum short term (less than 1/2 hour) temp is 250F. The maximum sustained temp is 220F.
If the trans goes over 220F for more than 1/2 hour, or ever hits 250F, find a safe place to stop and idle the truck in park or neutral. NEVER shut the engine off when the trans is really hot.
The maximum short term (less than 1/2 hour) temp is 250F. The maximum sustained temp is 220F.
If the trans goes over 220F for more than 1/2 hour, or ever hits 250F, find a safe place to stop and idle the truck in park or neutral. NEVER shut the engine off when the trans is really hot.
Does the same hold true for the 4R100 and other trannies as well? I've been told in the past that once you start hitting the 190-195 degrees, that's the danger zone.
Also, what is your opinion about bypassing the in-radiator tranny cooler? Could I get my tranny to run cooler if I bypass it and just run my auxillary cooler (pictured below)? It just seems like that if my coolant is running at between 180-190 degrees and the trans fluid is being routed through the radiator, then my trans fluid is being heated to whatever the coolant temp is.
One last thing. Is one gallon of trans fluid flow per minute normal for a 4R100?
The reason I ask these questions are because my tranny temp has been getting up to 190-200 degrees on a hot day just with normal highway and a little stop-and-go (traffic) driving. That doesn't seem right to me.
Thanks,
Will
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Joined: Dec 2003
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From: iowa
Will I can answer a couple of your questions, first this thread is about a 4R100 (thats what trans would be in a 2000 F250 PSD)
Next the 190-195 is often used as the safe limit but it's an old school number based on the old type F fluids, the newer fluids are a lot less prone to damage by the extra 20 degrees. IF you can keep the trans temp below 190 you are better off of coarse (ideally 170-180 is actually about perfect trans temp, but ideal and reality are different issues many times)
As to the aux cooler question, yes you can bypass the radiator adn in hotter climates I recommend it but I would suggest a bigger aux cooler then the one you have if it's your only trans cooler and your in a hot area.
Next the 190-195 is often used as the safe limit but it's an old school number based on the old type F fluids, the newer fluids are a lot less prone to damage by the extra 20 degrees. IF you can keep the trans temp below 190 you are better off of coarse (ideally 170-180 is actually about perfect trans temp, but ideal and reality are different issues many times)
As to the aux cooler question, yes you can bypass the radiator adn in hotter climates I recommend it but I would suggest a bigger aux cooler then the one you have if it's your only trans cooler and your in a hot area.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,696
Likes: 2,618
From: SE Florida
Your coolant runs about 190F, then is cooled in the radiator, then passes over the trans cooler. The coolant is anywhere from 15-100F cooler after the radiator than 190F. That's why there is a radiator, to remove heat from the coolant. The in tank cooler is a VERY effective way to ALWAYS cool the ATF. I've tested this from -40F to +120F and the ATF is ALWAYS cooler coming out of the radiator than it was going in. Even with a warmed up engine at -40F, the radiator is sucking heat out of the ATF.
With some stop and go driving that seems right to me, depending on what ambient you're in. Anywhere from 60-100F above ambient is normal.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
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From: Long Island USA
Mark, not to question anything you say, but ...
My '01's tranny runs at 150 degrees, even when it's over 90 degrees outside, regardless of whether I am doing stop-and-go or pulling any load or on the highway. Which is right at that 60 degree difference.
If it's going up to 190-200 without a load and just cruising around normally, that is usually the sign that the 4R100 is going to lose it soon. So many people have had that happen, I can't even begin to count the number after all the years of being on this site.
Again, not to question anything you say, but so many people have reported that they lost their 4R100 after running around for years at 150 degrees, and then suddenly going up into the 190-200 range.
kenneBF250V10, didn't you just change the fluid? Does your tranny have one of those funky cooler-bypass valves in the lines?
My '01's tranny runs at 150 degrees, even when it's over 90 degrees outside, regardless of whether I am doing stop-and-go or pulling any load or on the highway. Which is right at that 60 degree difference.
If it's going up to 190-200 without a load and just cruising around normally, that is usually the sign that the 4R100 is going to lose it soon. So many people have had that happen, I can't even begin to count the number after all the years of being on this site.
Again, not to question anything you say, but so many people have reported that they lost their 4R100 after running around for years at 150 degrees, and then suddenly going up into the 190-200 range.
kenneBF250V10, didn't you just change the fluid? Does your tranny have one of those funky cooler-bypass valves in the lines?
Elder User
Joined: Feb 2004
Posts: 772
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From: Mount Airy, MD
If you are talking about the bypass line that is physically mounted to the passenger side of the tranny, then yes I still have it on there.
Speaking of the tranny flush. In the week since I've had it done I have noticed a difference in shifting firmness. The Monster Box that I have is designed to have firm shifts and shift firmly it does. I've always ran MERCON but since I've had it flushed and filled with MERCON V, the shifting seems to be less firm, especially under full throttle. Does anyone know if this is normal?
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
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From: Long Island USA
Without really knowing, I'd say it's somewhat normal - why? Because Mercon V when I first switched one of my MN12's (t-bird/cougar 96/97) over, I smelled it, and it smelled of limited-slip friction-modifier.
The intention was to reduce the torque converter lockup shudder, and it certainly cured that in both the t-bird and the cougar.
So yeah, I'd expect it to let the clutches slip a little more, and not "chatter" or bang into gear as much.
Maybe the bypass line is stuck slightly open? But how to tell? Point-and-shoot thermometer?
The intention was to reduce the torque converter lockup shudder, and it certainly cured that in both the t-bird and the cougar.
So yeah, I'd expect it to let the clutches slip a little more, and not "chatter" or bang into gear as much.
Maybe the bypass line is stuck slightly open? But how to tell? Point-and-shoot thermometer?