I pull Sherwin Summit about 4 times a year. That grade will test any equipment, that's for sure. My TT weights about 7,000 ready to camp and I pull with a 2016 6.2 4.30. I will be in third most of the time turning about 4,000 -4,500 rpm. That gets me right at 50-55mph. I did drop to 2nd once when I got caught behind a slow moving truck and couldn't change lanes and lost my momentum. Go Gears, Gears, Gears. Not sure I can help on which one to use. I used to be in 1st when I pulled with my 08 F150 5.4. I feel your pain, been there done that. Yuck!!!!!!

 

2012 eco boost f150, 16 mpg tops empty, 8 with 6000 lb tt. i'm envious

 

I'm glad I read this! I've got almost the same situation as you had. I have an E-350 van with the 2V 5.4L that I tow my travel trailer with (6500 lbs empty). It generally does ok, but we just purchased an F-350 6.2 4.30 truck, haven't towed with it yet, and I was hoping there would be a good improvement in power.

 

My Truck is a 1999 early 7.3 diesel with 2WD 7.3 and automatic transmission. I am currently towing 9400 loaded but my last trailer was 12,300 loaded. And all though my truck is diesel and not a V10 like yours I would be in 2nd gear at 40mph in the same situation you described. I run a DP Tuner with 60HP towing tune. With that tune I also get enhanced shifting points similar to what you may see in the newer Towhaul transmission. If I wanted to better than that I would have to do a gear change like others have described.

 

My only comment is on the 210* trans temperature. That seems pretty high with the 6.0 cooler. Re-gearing will help , but what kind of shape is the trans in? Does it have any upgrades?

 

I agree on the transmission temp. I have had my 6.0 trans cooler in for several years now and have towed up to 12,000 lbs and my Trans temperature has always run 60 degrees above what ever the outside air temperature is. If it's 60 degrees outside the trans temp is 120 barley off the needle and if its 100 outside the trans temp is 160. I have never gone over 165 degrees....

 

Just scored on a cclb 2wd, and after I get ur done with fluids, parts..etc, I'm taking both trucks over to my bros shop to switch out the axles, since I'll be dumping the SC👍

 

Gearing in the dif is a multiplier.
IIRC, the v-10 2v had 430 ft-lb of torque, or there abouts. So we can see how dif gears affect thrust. We'll consider the 3.73 gears as the base starting point ...
Going from 3.73 to 4.30 gear is a 15% ratio change. Applied to 430 ft-lb from the engine adds the effect of another 65 ft-lb to be pushed down to the road. ("effect" is the correct term, as the engine output is not changed, but the force at road surface is directly affected by gearing change). Going up to 4.56 gears it a 22% change; net effect would be similar to 525 ft-lb and 3.73 base gears. (that's about as good as the old 7.3L PSD in stock form!).

Most easily understood this way ...
A stock 6.8L engine with 430 ft-lb and 4.30 gears will put down on the road the same force as stock 3.73 gears behind an engine modified to 495 ft-lb. It's far easier to add 15% effect to the gears than it is to get 15% more torque from the engine.


However, you also loose a corresponding amount of speed range for any gear of the tranny. 15% more torque multiplication also results in 15% less road speed for any given gear of the trans at a given rpm. But, you can 'hold" gears longer, and often get up one trans gear higher, with gearing reductions in the diff. Nothing comes free; there's always a trade off. However, I contend that diff gears really only make a significant effect at two places; 1st gear and top gear. Any other trans gear in between can essentially be shifted up/down to make up the torque multiplier you need. But you can never go lower than 1st, nor higher that top-gear, and so you're stuck with the multiplier effect as you only choice in those two conditions.


The v-10 is a good engine. It's just a 5.4L with two more cylinders added. But, it's an undersquare design; bore smaller than stroke. So, as much as it likes to make noise at higher rpms, it really does not like to rev. It will if you push it, but it's not really designed to be happy at high revs. It serves well in low to mid-rang rpm. And since you don't have a really wide powerband with the 6.8L, you have to make the most of gearing where the engine is happy with it's rpm.