Transmission Overheating
#1
Transmission Overheating
I have looked at so many transmission posts and can't seem to find an answer so here we go
2002 F 350 7.3 4x4
Aftermarket gauge will climb to 250° after around town driving of an hour or so or multiple trips within the hour. Not towing. 160,000 miles on odometer. Changed trans fluid at 40,000 mile intervals. Most recently about 1500 miles ago. Most recent change using Mark K's method. Was getting fluid from rear port when I changed fluid. Blew out oil cooler and there did not seem to be a blockage as flow was sufficient. Still overheating according to autometer trans gauge in test port. No codes retreived using autoenginuity also O/ D light is not flashing. Would like to run torque converter slip test using AE according to woodnthings method but TC slip desired and transmission gear ratio is not available under that name in live data meter. AE just updated to most recent version.
I purchased a new tranny oil bypass and will install soon. Also purchased a new 6.0 cooler to replace stocker but am hesitant to install if tranny is failing because I am concerned that the new cooler will just get some blockage from a potentially failing transmission and I will be buying a new cooler along with a BTS rebuild. Any help is appreciated.
Mike
2002 F 350 7.3 4x4
Aftermarket gauge will climb to 250° after around town driving of an hour or so or multiple trips within the hour. Not towing. 160,000 miles on odometer. Changed trans fluid at 40,000 mile intervals. Most recently about 1500 miles ago. Most recent change using Mark K's method. Was getting fluid from rear port when I changed fluid. Blew out oil cooler and there did not seem to be a blockage as flow was sufficient. Still overheating according to autometer trans gauge in test port. No codes retreived using autoenginuity also O/ D light is not flashing. Would like to run torque converter slip test using AE according to woodnthings method but TC slip desired and transmission gear ratio is not available under that name in live data meter. AE just updated to most recent version.
I purchased a new tranny oil bypass and will install soon. Also purchased a new 6.0 cooler to replace stocker but am hesitant to install if tranny is failing because I am concerned that the new cooler will just get some blockage from a potentially failing transmission and I will be buying a new cooler along with a BTS rebuild. Any help is appreciated.
Mike
#2
First off are you sure that you temp. readings are accurate? Thermocouples can go bad. The old cooler may be plugged/contaminated. I am running a Magnafine filter on mine post cooler as I bought a used one but have zero issues. You could install one ahead of the cooler just in case, but don't use two of them. Many question the use of a filter at all.
Unfortunately heat is generated by slipping parts in most cases.
Unfortunately heat is generated by slipping parts in most cases.
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#9
Clearly I'm AE deficient. Thanks for the reminder about checking the temps using AE. I checked them twice today and both times they were spot on with the gauge so I guess that rules out the cheap option.
#10
#11
Thanks Mark. I was hoping that you would chime in. I did run AE for a live session without the missing paramaters that Ken suggested (TC slip desired and gear ratio). Am I right in understanding that there will be significant torque converter slip until TC lockup? At 75 MPH on cruise control today the the TC slip actual was mostly less than 3.0 but there were times when I would see it jump above that 5.0 threshold. The terrain was mostly flat but there were some very mild up and down where I think the truck was adjusting to maintain speed. Would that reflect in TC slippage?
#12
#13
The converter clutch can release in this condition, which will cause the slip to go from nearly zero to a few hundred RPM.
#15
Also AE indicated that TC slip before lockup would be as high as 675. It even registered 1227 accelerating on to the highway then it leveled off to below 5 RPM difference. Is that what I should expect or is that as bad as I am hoping it is not?