I have 06 titan 4x4 crew cab w/towing package. I have used it to tow my toy hauler for the last 2 years, in NY, NH, Vermont, WV, Tn mt's without a problem. On my way home last week from West Va. on fairly level ground the Transmission heat gauge would go up rapidly when the truck was going up a very slight incline(even I could ride a bycycle up this sort of like on-ramp). As soon as I got to level the temp would drop back to the center of the guage fairly rapidly. At its hi point it was between the top line and the red. That same day I had been on extended 9% and 7% grades with no problem. I checked the fluid and it looks good and it is also full. I have not changed driving styles over the years and this is the first time it has happened. The ambient temp, was not as hi as on other occasions. I have gotten feedback about not useing OD and staying in 4th. I do not believe that is the problem because I have not changed driing styles and I sure did not on the day it happened. Also when I attemted to replicate without toy hauler on same road I could not get temp anywhere but normal. Help or suggestions would be greatly appreciated.

The advices to stay out of Cruise Control and out of 5th gear are valid. They are included in the owner's manual. Its a matter of the electronics keeping the engine/transmission in proper power range.

You mention that you are unable to duplicate the conditions without your toy-hauler in tow.

I suggest you check the brake wiring to you trailer's electric brakes. Check the wiring harness from end -to -end to insure no possible worn wires are shorting out and applying the brakes. Look in the area of the hitch and harness plug. Does your emergency Break-Away harness and connections look good? Check the brakes. Does one or more look like it has been dragging?

Also check your brake controller in the cab. Any changes there?

All of these checks are because I suspect there is something that has increased the towing load at some point causing the rise in temperature in the transmission. Whatever is causing the transmission to work extra hard is the source of the increased temperature in the transmission.

Also take a look at the transmission fluid coolers to see if they are obstructed.

Keep us informed as we want to know what you find out and what caused the temperature rise.

Red

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2005 Titan KC SE, Helwig, True-Track, ARE MX Canopy

Red: Thanks, This however is a question, if I had used 5th which I do on level ground could I have damaged something that is now showing up? I also now have some other good hypotheses to work on. I have dual axle on the toy hauler, how best to check the breaks on them? Should I jack it up and see if they spin freely? Also good idea on the plug, perhaps there is something that happened to the connection that has caused draging that is much worse up inclines versus level. I was also thinking about going to the beach and driving on the sand which puts a strain on the tranny and see if the same heating issues emerge?

One way to do a brake check is to drive normally around town some. Then pull into a parking lot and quickly get out and carefully touch each wheel of the trailer to see if any one (or more) of the four feels overly warm in comparison to the others. That one is much hotter would indicate that during normal driving it is dragging. Time to adjust the brakes.

I also forgot to mention getting the codes checked to see if your truck is storing fault codes. Most auto service shops as well as all Nissan dealerships can pull the codes to see what is what.

Red

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2005 Titan KC SE, Helwig, True-Track, ARE MX Canopy

im new on this so heres my question , when i tow like a small trailer or a car, i should go on 4 all the time and not use cruise control rigth? thanks