Ok so I have been thinking about purchasing a 4 inch Rancho kit for my 09 FX4 Supercrew and then adding some 35 Trail Grapplers. Probably 295/65/20. My stock gears are 3.73 and I won't have the money to re-gear. Will that tire to gear ratio be fine? I may get a programmer later down the road to help with the lost power but will have to save up for a while after doing all of this.

But anyway I was talking with a friend today and he said that he knows a couple of guys that had 35s on an F150 and the tranny blew after a while. He said they couldn't take the larger tires. Has anyone had this problem? And does anyone have enough miles - upwards of 100,000 with any issues with 35s and stock gears and no programmer?

I only have about 25,000 miles now but just don't want to run into any problems later on.

 

I ran 35's for thousand's of miles with a 3.73 gearset with no problems. I did have an Edge programmer that helped a lot. Just don't hot rod the truck with the large tires.

 

Did the Edge help out alot? I'll probably end up getting one in the future. If you don't mind me asking, how much did you buy it for?

 

And also what programmer do you think would be best for this situation?

 

You will be fine with 35's, I had 35's on my 05 FX4 and now have 35's on my FX2 with 3.55's. However, I just ordered a tuner and plan on upgrading gears to 4.10.

 

It really depends on how you drive and what your expectations are. I had 33" tires and 3.73 gear and hated it. I'm back to lighter stock 32" tires and am happier. But I want 4.56 gears and 32" tires.

Keep in mind larger tires are heavier. 35" tires are in the 65+ pound range. This affects vehicle performance a lot more than adding 100 more pounds of dead weight in the truck bed or cab. It takes a lot more energy to turn and stop that weight. Fuel economy, brake wear, suspension components are all affected. By how much depends on how you drive your truck. This is why some people think 35" tires and 3.55 gears are fine and others think 33" tires and 3.73 suck.

 

I guess it largely depends on how you use your truck. I have 35's on my truck with a 6" lift, stock gears and no programmer (yet). I don't do any serious hauling or drive it hard so this set up works fine for me. I am thinking about adding a programmer down the road mainly to help out with the horrible gas mileage.

 

the only thing you could do to help your 'horrible' gas milage is to use a shorter lift kit and narrow tires and appropriately re-gear, the programmer wont help. you're dealing with physics right now.

 

Marshall, I know that you have a similar truck to what the OP has. I remember that you plan on getting 35's for your wheels too, if I am not mistaken. Maybe explain to him what gears you would like to see in your truck, after the new tires, and why... and the negatives of doing it.

For every action, there is an equal and opposite reaction. Speaking of physics.

Oh, and congrats on the new addition to the family.

 

Well this has got me thinking...It seems like it may be better to just go with a level. Maybe do the bilsteins 5100 and add some 34 inch tires that are not as wide. Then I wouldn't have to deal with all of these problems, but still have some negative effects though. Seems like there is a lot more than I thought that goes into all of this when lifting and adding some much larger tires.

 

the best breakdown of information i can give is this:

1, modern aerodynamics or not your truck has roughly the same properties as a barn flying sideways down the interstate. the higher you lift it in the air the more distance the air has to travel to strike the windshield and flow over the top. also, the higher off the ground it is the more useless the splitter and air damn the factory provides you with becomes. right now that straight flap under your radiator is creating turbulence to force air below the truck at road level so it does not encounter things like the muffler, frame, oil pan, trasfercase etc...

2, a programmer will help increase horsepower and torque, but you're still dealing with the mathematics of gear ratios. with the added height of the 35" tire you're decreasing the amount of leverage your drive train has at the ring and pinion. by that principle, your engine would have a higher horsepower and torque output, but would still need to push just as hard to get that ring and pinion to move to turn your tires. by re-gearing to an appropriate gear set you're increasing your leverage thus making it easier.

so yes, your engine will spin faster, but that doesn't necessarily mean that you'll be burning more fuel. you might keep your current fuel milage, improve slightly or actually lose milage - all based on your choice in gearing. i personally want to instal 4.56 gears in my truck because that is 1 step over a "fuel economic" standard for that tire size. fuel milage does matter me (which is why im not getting 4.88's) but id prefer to have more gear than i need than not enough. i like to remind people that our trucks have an electronic governor set for 97MPH. so whats the point in having a gear set that will keep your engine going past that if its not capable of it?

another thing that people dont realize is that the difference between 4.10 and 4.88 is fairly large, but the difference between 4.11 and 4.56 or 4.56 and 4.88 is fairly small, about a 300RPM difference roughly. in my experience with Jeeps and those choices with regearing for tire size always get 1 gear set higher than you think you'll want, because you'll grow into it.

3, the other issue you have is the width of your tire and how far it will stick out from the body. if you're really concerned with fuel milage a narrower, all terrain tire offers much less rolling resistance than a knobby wide tire. there are manufacturers that make 35's in the 10.5" wide styles like which what your truck came with. also, by using low offset wheels (closest to 0 as possible) you can keep the tires tucked in the body. the same principle of aerodynamics effects the "excess" tire.

for me, im not choosing fuel economy for any of these reasons. i want my tires to stick out, i want meaty wide ones at that. i want a tall gear ratio for more power to the ground. the only reason why im using a leveling kit is to maximize ground clearance (no drop bracket) and keep a very low center of gravity.

its all in the choices you make. take your time and make an educated one that you have room to grow into. that way the newness lasts longer and you'll be happier in the long run.

 

I'm running a 35" toyo mt and I really like it. I mean its slow but my truck isn't fast to begin with so it doesn't really bother me. I don't haul too much just my grizzly 700 and and trailer with a Polaris 800 and it does that good enough for me. oh and i have 3.73 gears.

 

And let's not forget about the potential ADVANCETRAC WITH ROLL STABILITY CONTROL (RSC) STABILITY ENHANCEMENT SYSTEM issues.

Here are two threads from this forum (there are other threads on other boards).

https://www.f150online.com/forums/20...es-2010-a.html

https://www.f150online.com/forums/20...lp-needed.html

 

Good info.. With that said, What is the ideal gears for a 2010 6 speed tranny with 35's? I was planning on going with 4.10's but would 4.56's be a better option since I have a 6 speed?

 

True..True.. Im having these issues but there is supposed to be an ABS update that the dealer can do to stop the AdvanceTrac from kicking in with larger tires.. I have not had a chance to get to the dealer for this update but plan on doing it soon