ajb0812

What are you towing? It could be a problem with the truck or if its something really heavy maybe you're just expecting too much. Hard to tell without knowing more details.

Triton_tom

I'm towing a 20' gooseneck loaded with scrap metal, there is nothing wrong with the truck I just got it tuned up by the dealership. When pulling the trailer the truck seems to have no low end torque.

4x4angel

You got problem some where else . My stock setup fx4 3:73. 5.4 can tow my 6000lbs. Trailer up to a 100 mph like nothing

nagata

I'm not trying to drag your thread off-topic, but have you by chance had your loaded gooseneck weighed? I'm asking because I believe that set up could easily be pushing 10k pounds or more, which would be right at or above your truck's towing capacity. If the loaded trailer does weigh that much, and you're towing that load on a regular basis, in MY opinion, I think you're looking in the wrong place for a solution. Regearing your 1/2 ton to try to give it the capability of a 3/4 or 1 ton is like trying to use a framing hammer in place of a sledge: the framing hammer might get the job done, but it's gonna be harder, and the framing hammer just might break.

That being said, I speak from experience when I say that regearing differentials is expensive, and it's a job that REQUIRES an experienced mechanic, one who's performed the job numerous times. If you go cheap, there's a good chance the installation won't be correct and you'll have major issues in the future. I believe you know that both differentials have to be regeared simulateously. Lastly, I think 4.10s would help some, but I agree that for the amount of money you'll spend, you would be better suited to go with lower gears...assuming that you can accept the decrease in fuel mileage.

05F150XLT

I have a 5.4 4x4, and my pinion is 10.75 I think. Way bigger then I though...

thump

@Triton_tom - regearing won't be your answer. I'm running 4.56's and towing in the mountains still sucks. It's the lack of O2. According to one of the best performance/dyno shops in Denver, you're looking at 30% less power from sea level just to Denver altitude for an NA vehicle. Add in a 10K+ mountain pass and 6%+ grades and your towing power drops to hell. The only real answer is add an SC, or buy turbo-diesel.

Triton_tom

I really wish I could upgrade to a different truck and or supercharge but those options are out the window. I talked to a gear shop and they told me the 4.10 gears would help out. What if I found a wrecked heavy duty f150 and swapped the running gear into my truck?

BassAckwards

You could but now you'll have 7-lug wheels in the back and you still need to regear your front.

Triton_tom

What I meant was swapping both the front and rear.

thump

I think it would work, but not sure if you'll find those parts for any less than doing a gear swap.

Still, I think you'll find the difference between 3.73s and 4.10s to be a pretty minimal gain for the price. Running a programmer with premium fuel would be a much cheaper start.