# Tranmission temp bouncing from normal to completely HOT



## RamirezOrchards (Jan 13, 2010)

Whenever I start driving the transmission temp starts out fine and then once it starts climbing to the normal tranny operating temp, it shoots completely up for a few seconds and then climbs back down instantly to normal only to do it all over again all the time. I had autozone pull the code and it read hot transmission temp gauge. I check the fluid and it seems fine. The truck drives fine as well. Is there anything that usually makes the transmission sensor act up? It seems to be the sensor. Are they difficult to swap out? Thanks in advance for the input

Forgot to mention I have a 2003 Ford F350 6.0L diesel supercab auto


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## EGLC (Nov 8, 2007)

Make sure your fan shroud isn't tweaked and causing the fan to stop blowing in air. I know it sounds stupid, BUT when that fan isn't going the truck will overheat.

I had this problem on my 03 chevy 2500 gasser.....


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## veggin psd (Feb 8, 2007)

When it happens, crawl under the truck and look at the passenger side of the trans. Follow the cooler lines back and feel the Trans cooler bypass. It is the tubing linking the return and output to the cooler. Check by "feel". If the trans line is a lot cooler than the tube between the ports, you likey had your bypass valve fail. Cheap easy fix.

I strongly recommend anyone plowing with a ford make the minimal investment into a transmission temp gauge. Isspro is about the best, IMHO, just dont buy a cheap one. 

IIRC the temp gauge on the dash is just like an idiot light. No real accuracy there. By the time it reads warm, its hot, and too late. Bye Bye torque converter.


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## Ford555 (Jan 30, 2010)

The guy who works for me has an 03 F350 sc 6.0/Torqueshift. It was the transmission temp sending unit. I installed it for him last year. It was under $20 from Ford. You have to drop the pan to get at the sending unit. I had to use a little pick to get it out. Make sure you have enough Mercon SP ATF on hand (aprox 8 quarts) and change the filter inside the pan at the same time.


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## RamirezOrchards (Jan 13, 2010)

Ford555;980454 said:


> The guy who works for me has an 03 F350 sc 6.0/Torqueshift. It was the transmission temp sending unit. I installed it for him last year. It was under $20 from Ford. You have to drop the pan to get at the sending unit. I had to use a little pick to get it out. Make sure you have enough Mercon SP ATF on hand (aprox 8 quarts) and change the filter inside the pan at the same time.


Thanks!!! I will get it in the shop ASAP and have it swapped out. Cheers :waving:


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