I have a 2003 F350 crew cab "King Ranch" 4x2 V10 Auto trans with trailer towing option. Also has air bag suspension added to rear axle. Has been used by PO to haul 5th wheel RV and we will be doing the same.

I checked with Ford specs to see what max GVWR would be for 5th wheel and all they show is ratings for 3.73 and 4.30 gears.

3.73 = 10,600 5th wheel GVWR
4.30 = 13,600 5th wheel GVWR

Does anyone have any idea what the tow rating would be with 4.10 gears??

The truck currently has a 4.10 gear set.

 

If I use the following calculations, would I be fairly accurate?

The difference between 10,600 and 13,600 = 3,000 lbs

430-373=57
410-373=47

47/57*3000=2473

Therefore, 10600 + 2473 = 13073 Lbs towing capacity with 4.10 gears

 

No, you would not. It would be in the 11,500 to 12,000 range. You calculations approx the 4.30 gear when the 4.10 is only slightly over 50% difference between 3.73 and 4.30.

3.73 --- 4.10
------ * ----- = 11,651
10,600 --- X

4.30 --- 4.10
----- * ------ = 12,872
13,500 --- X

I would take and average of the two. I would use 12,261 as a WAG (Wild A$$ Guess)

 

Sounds good to me.

I realized I made a simple math error.... 410-373 is 37, not 47

Therefore, 37/57*3000=1948

10,600 + 1,948 = 12,548 so between you and I, I think I'm good as the max GVWR of my 5er is 12,400 and it's unlikely I'll hit that as it has a 3,000 Lb ccc.

 

How did that truck get 4.10's? Pretty sure 3.73 and 4.30 were the only option with V10's. Probably why Ford doesn't show towing weights. 4.10 were avail with the 5.4L. 4.30's would be the best choice for towing.

 

While 3.73 and 4.30 is factory options, 4.10 gears will also fit.

 

Yes they will but Ford didn't use them on the V10 till 2005. Someone else installed them.

 

Right, but the OP didn't say the truck came from the factory that way. I re-geared my 06 Powerstroke from 3.73 to 4.10. Worked great for carrying a truck camper high in the mountains.

 

Agreed don't waste your money of 4:10 go to 4:30.

 

Random question - but howcome Ford didn't offer the 5.4 with 4.30 gears? Seems like it could use them.

 

They did not a lot of dealers ordered them with 4.30s though so if you wanted one you had to special order it for the most part or get lucky on the lot.

 

I can understand needing 4.30 gears behind a 5.4 engine but I believe 4.10 gears behind a V10 will be just fine with my trailer.

That said, I haven't pulled it with the 4.10 gears yet but I did with the 3.73 and while it dragged some on hills, it was fine on the flats.

 

In my opinion the cost to have 4.10 installed does not make it worth the little gain you will get as it wont act much different than your 3.73s. If I did it again I would have went with 4.56 on my 5.4.

 

I ordered my 2007 f350 ccsb 4x4 v10 with 4.10 axles. I have towed my 14,500 lb 5th wheel across North America 5 times and have never wanted for more. I understand the desire for more power but can say I have not felt lacking once. I also hauled a goose neck from Nova Scotia to Calgary and grossed out at 27500 lbs. The truck handled it very well and did not struggle at any time. I kept the speed to 60-70 mph and relaxed.


When I put my 35" tires on you can feel a difference in the pulling power but with the 33" tires it is a very competent puller. If you pull the majority of the time you will find 4.30 or more a benefit but for the most part 4.10 is just fine with me. Sometimes I think we talk ourselves into things that don't really matter. But hey, do what makes you happy. If you don't want to spend the money I'm sure you will be ok at 4.10 or even 3.73. Turn up the tunes, have a coffee and relax. You might get there 15 minutes later with 3.73's than 4.56's.


Cheers...

 

I disagree ... but that's my opinion.

With the 5.4 you probably needed 4.56 considering what you were hauling and where.

Thing is, I didn't come here to seek opinions on what is better, what I should do or not do, nor am I interested in getting into a debate over it ... I wanted to find a realistic towing capacity for a 4.10 gear set and that has been answered and I thank those who assisted in that.