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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47267
Experience:  16 years experience
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2002 ford explorer: auto trans..Tranmission oil..speed sensor..cooler

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2002 ford explorer 4 speed auto trans . Tranmission oil getting so hot melting turbin speed sensor. Replaced trans cooler and filter.

Hello, I'm Chris.
I will do my best to answer your question fast and accurate using the info you have provided. Thanks for visiting Just Answer.


The TSS and ISS and OSS can withstand temps over 350 degrees. Transmissions operate at 200 degrees, transmission seals fail at 250 degrees. If the transmission is not ruined and totaled then its not getting hot enough to melt a seal. To melt a seal you must a external heat concern from the exhaust or the tone ring inside the transmission is hitting the sensor and grinding the head off the sensor.

Customer: replied 6 years ago.
graphicgraphicIll start from the begining O/D light started to flicker. Checked under the SUV . Spotted a small oil leak from the tranmission cooler. Dropped trans oil pan,oil was dark, no burnt smell,found metal peice from the turbine sensor no plastic peices. Replaced sensor,cooler,filter,oil. This is the third sensor i installed with the same result. The sensor does look like it been hit,but it looks like theres some melting going on to?. What would cause the tone ring to move and start hitting the sensor. After installing a new sensor trans works fine for about 100 km, then O/D starts to flicker.Then trans has shifting problems. What is the tone ring made out of? Could the tone ring warp from over heating. From being low on oil?. The plastic peices from the first sensor that i have`nt been able to find , might be causing a oil flow problem. Sealed unit trans are a pain. If there was a dip stick, problem would of been spotted sooner

There is something else going on here, there is no way a transmission could survive after getting hot enough to melt sensors. much less its only affecting the TSS when the OSS and ISS are the exact same material. Have you actually hooked up a scan tool and watched the fluid temp sensor to see if the temp is actually high or not.


For the Carrier - planetary gear overdrive (with trigger wheel) to wobble and hit the sensor the center support has to have bushing damage or the front carriers worn out and wobbling.


Customer: replied 6 years ago.
There must be one hex of a wobble to damage the tss sensor , there was`nt much left of the first tss sensor. You would think a person could feel it or hear it. Runs pretty smooth for the first 100 km ,then the tss sensor gets damaged and fails. Then the shifting problems start. By the location of the damage on the tss sensor " top-front" the front carriers worn out and wobbling. Bushing worn out or carrier is rubbing on something and creating heat and melting part of the sensor .Do you have any pictures of this area of the trans? I have not hook it up to a scan tool.I have a backyard code reader. Would`nt the engine light come on if the trans oil temp got to high?

If the trans gets over 240 F the dash will warn you. Its gonna take over 300F to melt plastic. Regardless of what you decide getting to hot or the sensor being hit, its gonna need to come out and get overhauled, Below are some pictures.


Disassembled view down loadable here

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