Towing in 4th VS 5th Video

So, I see a lot of questions about towing in 4th with the auto trans.

I also see a lot of "should I get a ScanGauge?"

I took a video earlier while climbing a big hill on I80 in NJ while towing my trailer home from PA.

My trailer weighs 1800 LBS. In the trailer I had my 700 LB wood splitter. In the back of my truck I had another couple hundred LBS of chainsaws and tools.



Here's the video. http://s870.photobucket.com/user/Mi...-7670F212246B_zpsdwosv510.mp4.html?sort=3&o=0 Started up the hill in 5th, shifted down to 4th at 192*. As you'll see, the trans temp dropped quickly as soon as the torque convertor locked in 4th. This is all while maintaining roughly 65 MPH

"TF1" is the temp at the pan

"TF2" is the temp at the torque convertor

I'll let you decide by the video if you think you need a ScanGauge, or another way to monitor trans temp, or what gear you want to tow in.

 

Doesn't get much more proof positive than that. What temp does transmission fluid break down?

 

Here's a chart I just found. http://www.txchange.com/heatchrt.htm There's a better one on here somewhere... Basically, the hotter it is, the faster it breaks down.

 

yup, if you cant hold 5th lockup... downshift to 4th so you can hold lockup and keep temps down.

FYI those temps arnt bad, PAN temp is what you really have to worry about, the torque converter output temp (TF2 in this case) is going to read hot when the torque converter is unlocked by nature of the way the torque converter works (this is why the auto trans will not go into lockup when its cold to aid in heating up the trans to get it to operating temp quicker). But if the cooling system is working properly pan temps wont rise much (as you can see in this vid, pan temps only went up 10*F during the period of time the tq converter was unlocked). But constantly running unlocked pan temps (which is the majority of the trans fluid temp) will rise and rise to the point of getting real warm, and at that point you start to break things down.

 

Yeah, I should've noted that I have installed a larger trans cooler and it was only 17* this morning. Those two things, obviously, keep the pan temps lower. Like you said though, if the convertor is unlocked, the temps rise fast no matter the size of the cooler.

 

Or you could keep it in 4 like the manual says and forget about it. Why would you keep it in D? To save a couple dollars in gas?

 

I couldn't care less what gear you tow in. I just made the video to show the difference because people are always asking.

 

Good stuff OZ!