I just purchased a 2010 F150 XLT Supercrew 4x4. I have the 5.4 and 3.55 gear. I immediately had a leveling kit and 325 BFGs installed. Tires are about 34.6" tall. I notice a little big of lugging at highway speeds and downshifting on hills at 60mph. I need some advice. Should I change out the gears to 4.10 (or higher) or should I just suck it up, or go with a smaller tire?

This is a brand new truck. I only have 1300 miles. Would changing the gear be going too far. It's been a long time since I've had a new truck and I don't want to screw this one up.

Everyone around here recommended one guy that I'd heard of before and he quoted about $850 to change front and back to 4.10. Is that a good price?

Thanks in advance for any insight.

 

That is a great price! I'd go for 4.56 with heavy 35" tires, though.

 

Thanks for the advice. I thought I'd have more people chiming in on this though. I'm going back by the shop to talk to the guy this afternoon. He asked that I stop back by to give him time to verify gear prices.

 

Is that parts and labor? If so, that's a steal - parts alone are $500-700 depending on where you buy them. Of course with those low miles you won't need master rebuild kits, so that will save some.

If it were an 01-08 I would say 4.56, but I'm not aware of the new 6spd tranny ratios, you might be ok with 4.10s and still have low end power due to lower 6spd 1-2 gears, but still get good hwy mileage.

 

6th gear = old 4th gear. 0.69 vs. 0.70, almost the same. 6-spd is really the lower 5 gears replacing the old lower 3. If the problem is not holding top gear(s), then I'd say 4.56. I don't think lower speed acceleration is much of an issue with the 6-spd.

Probably be happy with either choice. If you tow much weight/often, then 4.56. I'm a more aggressive driver so another reason why I like the shorter gearing.

 

I don't really tow anything but I would like to be able to. Thinking of getting a camper.

So I guess no here is against me doing this to a brand new truck? If I don't change the gears, how will it affect the truck? Is it going to shorten the life of the transmission or anything else? I know I can't tow as much with the larger tires altering the actual gear.

I thought that was cheap too but he said he was going to get new gears from the Ford dealership and that he was going to call to verify pricing and wanted me to check back today. I may get my feelings hurt when I go back.

One more thing, if he gets the gears from Ford how does this affect my warranty? I know the work he does will not be under warranty except through him (hopefully). Is this something I should worry about? I've never had any problems with differentials going out but I'm not usually turning 35" tires, towing etc.

Thanks guys for all of your insight.

 

1st in the 6 speed is a 4 point something ratio - considerably lower than 1st in the 4 speed. When tuners for the 10's are available, you may just be able to get a tune and it will run better. You are going to have to do something to correct the speedo/odo anyway with the taller tires.

 

I've got a connection at the dealer that's going to calibrate my speedo for free. I was just going to wait to see if I changed the gear and let him do it all at the same time. Don't want to bother him too much and use up all my favors. If you think that will get me back where I need to be, I'll take it to him tomorrow.

 

I put 275/65/20s(34s) on my 2010 and after the tuner, everything is almost back to the stock feel. Almost the same hwy mileage and Better acceleration. Of course, gears and a tuner would really be amazing but you can probably get by without them.

 

i would change them out to 4.56

 

Well I stopped by the shop to see if the guy had verified pricing for the gears and he's been too busy to call, so I'll have to check back with him later. I think I might go ahead and get the speedo calibrated while I'm waiting on him.

I don't really feel like the truck has lost any power, not enough to worry about. It's not always downshifting, just certain hills at certain speeds. Drove it to work today and to the beach tonight and everything feels good.

 

When available, a tuner is going to be considerably less expensive than a gear swap.