putt4doe

I'm trying to figure out what axle ratio I should get on my new F-150 (might get the 250 - still deciding)

Either way, I'm curious... I currently have a 3.55 non-limited slip axle, however, sometimes it binds in 4x4 (as they all do)... If I went with the 3.55 electronically locking axle ratio, would it reduce the binding when in 4x4?

What's the major difference, and why should I get one over the other? What are the pros/cons?

Thanks!

iFord

Good answers coming soon, unfortunately, no good ones from me. I don't so much. Mine is also 3:55 limited slip or some such. They'll be asking about towing, etc., but you already know about all that.

Okay boys, chime in, help old putt!

Fx4_5.0Man

iTrader: (1)

Gear ratio should not matter or make a difference in the binding situation.

Fx4_5.0Man

iTrader: (1)

I vote at least 3.73 in everything I own.

StonedGreen

yeah the 3.55's are a little slouchy as I have them also. the 3.73s make the truck feel some much lighter and zippy. If I could, I'd go 4.10 as it would make acceleration so much quicker, but the fuel consumption would be killer

RandyZie

What's the hit on fuel economy 3.55 vs 3.73

putt4doe

Is there a difference in the binding between an electronic limited slip vs. a non-limited slip axle?

rancheroracer

I wouldn't think so, the binding is caused by the different radius the front takes vs the rear, not the limit slip or not.

Also, considering 3.73 vs 3.55 for acceleration, my '12 with 3.55s ran the same 1/4 mile ETs as my '11 with 3.73s stock. These trannies have such a low 1st gear that my '12 still launches very hard & it doesn't seem to hurt the acceleration down the track either. I'm even considering 3.31s when I order a '15 if they're still available.

Curmudgeon

3.31 will be available with all engines except the NA 3.5; 3.15 will be available only with the 3.5 EB.

ClaySlayer

ugh...you shouldn't be putting the truck in 4x4 when on solid enough terrain to cause binding. As others have said it doesn't matter what ratio you have it'll bind.

Ratio depends on what motor you have. If you're 4x4 and going to put a bigger size tire on then I vote 3.73s. Only way I would go 3.55 or even 3.31 is if staying with stock size tires or not towing very much weigh...unless it's the 3.5 EB because of the low end grunt...I talked to a guy at a boat ramp one time that towed a ~25' runabout that weighed about 8,000lbs with a 3.55 EB and said it had plenty of power. I had a 2wd, 5.0, 3.31 rental for a week and it was plenty quick and would've handled a good sized trailer with no problem. Now when you do the math a 3.31 with the stock 2wd tires (~30in) is effectively the same ratio as my FX4 with 33s and 3.73s...plus mine weighs about 800lbs more for the camper shell, crap in the bed,and 4wd components so it makes since that the 3.31 truck I had felt zippy. If it weren't for having 500lbs of crap in my bed plus bigger tires I would've been fine with 3.55s or even 3.31s and when I tow my ~4,000lb boat on the weekend could just lock out 6th and run in 5th if I needed to.