- Joined
- Dec 28, 2008
- Messages
- 1,454
- Reaction score
- 33
- Location
- Wisconsin
- Vehicle Year
- 2006
- Make / Model
- Ford
- Engine Size
- 6.0L Powerstroke
- Transmission
- Automatic
First off, yes I tow and haul in overdrive... within reason of course. I picked up a scangauge and it gives plenty of reference as to what my truck is doing. Before I get all scatterbrained, here's what I have, what I do, and why I do it.
I use a 2005 ranger 4x4 with the 5R55E trans (larger cooler) 4.10:1 rear gears on 265/75R16. As for the trans, I have an SCT programmer which allows me to increase/decrease transmission line pressure upto 25%. Using the scangauge's "transmission line pressure" readout, I can in fact see the difference.
What usually do, is haul atvs and gear. The 400ex goes into the bed (400lbs) the banshee (400lbs) goes onto a small 4x6 trailer (200lbs) and the fuel + baggage might be another 100lbs. Not much wind resistance, looking at an increase of roughly 1100lbs.
Why do I tow in overdrive? Well because at interstate speeds I run at 2500rpm in overdrive and maintain 15mpg with this vs. 10-11mpg running upwards of 3700rpm. First off, similar RBVs such as the explorer weigh in at almost 1000lbs more than my ranger and run overdrive all the time every day in OD. Second, it is my belief that the Overdrive gearset/bands themselves must be somewhat stout or ford wouldn't engage it under heavy throttle to split first and third gear on the 5R55E. What I believe does kill the trans is heat and bands slipping. I monitor the line pressure and have no "drops" during extended cruising. My trans fluid reaches 150 degrees quickly (valve body has a t-stat that opens about then) and when towing in od or drive I never seen anything above 185. If the transmission stays in overdrive without "hunting" or cycling the torque converter clutch (locking and unlocking) I feel there is no harm in towing in overdrive. How can a trans build more heat than the cooler can dissipate if the torque converter is locked at 70mph? I understand that if the torque converter stays unlocked you are now multiplying the engines torque (which is then applied to the OD unit) and the slipping produces a lot heat.
My truck does not have an issue unlocking the T.C. or hunting unless I face a tough headwind or hills (which I'll just leave it in Drive). So, what's others opinions on the subject? I want to know what is fact and what is myth. What do you do? Should there be a general "don't tow/haul with od" or are their exeptions.
Also, what is your opinions about the strength of overdrive itself. If it truely is weak, why under wide open throttle will it apply all of the 4.0Ls torque (multiplied by the converter) to the overdrive set +1st gear?
I use a 2005 ranger 4x4 with the 5R55E trans (larger cooler) 4.10:1 rear gears on 265/75R16. As for the trans, I have an SCT programmer which allows me to increase/decrease transmission line pressure upto 25%. Using the scangauge's "transmission line pressure" readout, I can in fact see the difference.
What usually do, is haul atvs and gear. The 400ex goes into the bed (400lbs) the banshee (400lbs) goes onto a small 4x6 trailer (200lbs) and the fuel + baggage might be another 100lbs. Not much wind resistance, looking at an increase of roughly 1100lbs.
Why do I tow in overdrive? Well because at interstate speeds I run at 2500rpm in overdrive and maintain 15mpg with this vs. 10-11mpg running upwards of 3700rpm. First off, similar RBVs such as the explorer weigh in at almost 1000lbs more than my ranger and run overdrive all the time every day in OD. Second, it is my belief that the Overdrive gearset/bands themselves must be somewhat stout or ford wouldn't engage it under heavy throttle to split first and third gear on the 5R55E. What I believe does kill the trans is heat and bands slipping. I monitor the line pressure and have no "drops" during extended cruising. My trans fluid reaches 150 degrees quickly (valve body has a t-stat that opens about then) and when towing in od or drive I never seen anything above 185. If the transmission stays in overdrive without "hunting" or cycling the torque converter clutch (locking and unlocking) I feel there is no harm in towing in overdrive. How can a trans build more heat than the cooler can dissipate if the torque converter is locked at 70mph? I understand that if the torque converter stays unlocked you are now multiplying the engines torque (which is then applied to the OD unit) and the slipping produces a lot heat.
My truck does not have an issue unlocking the T.C. or hunting unless I face a tough headwind or hills (which I'll just leave it in Drive). So, what's others opinions on the subject? I want to know what is fact and what is myth. What do you do? Should there be a general "don't tow/haul with od" or are their exeptions.
Also, what is your opinions about the strength of overdrive itself. If it truely is weak, why under wide open throttle will it apply all of the 4.0Ls torque (multiplied by the converter) to the overdrive set +1st gear?