Trans temp issue

[E2360]

Just had the trans fluild and filter change(not a flush) 30,000 miles. second drain/filter change. After the change, I noticed fluid temps are higher than usual from before change. Temp measured in outflow coolant line. Prior to change temps would almost always be below 150 around town, on xway even lower. Since change temps are consistantly in the 180 range.



I am under the impression that there is a valve associated with the filter.



Question is: are these temps in line with what others are seeing. Is there a restriction in flow with new filter or was there an issue with prior filter set up.



Thanks for your input.

 

[AH64ID]

If your seeing higher temps for the same driving... dont forget about outside air temp increases. . then its possible they goofed the filter install.

 

[E2360]

Ambient temp here have been unseasonably COOL. Thought about that, does not seem to be a variable. Can not locate "Normal" operating temp data to see if before I was running "Too Cool"???

 

[GaryOwen]

Could wrong fluid have been used? I know it is a different beast, but my 95 runs about 165 normally when empty.

 

[AH64ID]

I don't know if you can run too cool...

 

[cerberusiam]

The prior temps were too low, what you are seeing now is about right.



Somewhere around 180 driving around town and 10-20 cooler at steady hiway speeds.



First thing to check is between CAC and radiator to make sure there are leaves, bugs, etc, stuck in there.



The only valve in the cooling system is the anti-drainback valve located at the front of the truck where the coolant line enters the cooler. It is possible it has collected garbage that will slow flow.



What gauge do you have and how many wires on the sender? If it is a 1 wire sender you need an extra ground wire to make it work correctly. If not check your grounding point connections.

 

[ScottLewis]

I had my transmission serviced at the dealer recently and also found temp to run higher afterward. They did the "full fluid flush".

Normal driving isn't much different but slow towing up a grade reached over 230* and it never had gotten that high before. It was pretty hot outside and the hill was fairly steep w/ a 20 MPH limit. The dealer tech checked it out and said that fluid was good and that temp wasn't excessive. He said to bring it back if I noticed further problems. Only one towing trip since and I didn't see a repeat.



Dan

 

[E2360]

Thanks for the input. Running dipricol guages, single wire but excellect ground through the tubing. (0 ohms resistance sender housing to Battery)



Work order lists parts as filter valve thus my thinking it contained a valve. Must mean filter for valve body?????

 

[cerberusiam]

Thanks for the input. Running dipricol guages, single wire but excellect ground through the tubing. (0 ohms resistance sender housing to Battery)

Doubtful it is consistent connection though as its common problem with single wire gauges and you cannot rely on the tubing ground.



If the control box is grounded to chassis, ground the sender unit to a chassis ground also. Backfeeding the ground thru the battery generally will cause incorrect readings.

 

[RonD]

I have the same trans temp setup on my 48RE trans, why would you have to run a ground from the frame to the probe housing ?, mine is screwed into the trans pan, the pane is bolted to the engine, the engine is grounded, am I missing something?, just making sure.

 

[cerberusiam]

I have the same trans temp setup on my 48RE trans, why would you have to run a ground from the frame to the probe housing ?, mine is screwed into the trans pan, the pane is bolted to the engine, the engine is grounded, am I missing something?, just making sure.

Consider the electrical conductivity of aluminum and its alloys is about 60% of copper, what happens to the signal? That and the warmer it gets the lower the conductivity goes.



Depending on how sensitive the box is that reads the signal, you can have invalid readings and not know it due to the way the the circuit was tested and built.



Relying on good circuit thru aluminum is not a good idea as it changes with the heat. That and most of the gauges that are one wire run consistently low until grounded with copper to a chassis ground like the box.



That said, not all exhibit this trait and it can be the box's sensitivity that is off, but, when in doubt or questioning the readings, ground it.