I have a 2005 F150 4X4 regular cab with a 4.6. I need to occasionally tow a two horse trailer. The 3:55 gears are awful. I have thoughts of putting 4:10 gears in the truck as this would be cheaper than buying a new truck. I love my truck. It has given me 68k trouble free miles.

I understand 4:10's will hurt mileage but how much? My other option would be 3:73 gears. Would I really be able to tell a difference if I go with 3:73's?

So here is the option.

Leave it alone and deal with the high 3:55 gears
Compromise and go with the 3:73's
Go with 4:10's and enjoy the extra grunt and take off?

 

What is your typical driving other than the occasional trailer tow? If you do a lot of freeway driving at 80 mph, you probably won't like the 4.10's for very long with the engine being wound out. If you do mostly city driving, you would probably love the 4.10's and would't see any loss in mileage.

Has anyone sucessfully put 4.10's into these trucks yet? Seems like Ford only offered 4.56 above 3.73 and some people were not having real good luck with non-Ford gears in these axles.

 

i dont think you would see much of a change with 3.73's,especially if you have taller than stock tires on your truck

 

I looked into this and I would go with the 4:10. I would get 33" tires or so next time you need tires and then those combined with the 4:10 should be perfect.

 

4.10 at the least , I would say. As a performance upgrade, I have been recommending 4.56 gears to customers, even with stock size tires on lowered trucks. The mileage changes are negligible, but the performance and available torque are much improved, its a win win situation as far as i know.

Also keep in mind that on a 4x4 youll need to do the front and rear axles. Parts and labor on a change like this can quickly approach $2000, so I would take that into consideration.

 

For the money, only moving to 3.73 is going to be a waste. If you are going to spend the cash, I think the noticeable improvement will come with 4.10s.

 

Has anyone sucessfully put 4.10's into these trucks yet? Seems like Ford only offered 4.56 above 3.73 and some people were not having real good luck with non-Ford gears in these axles.[/QUOTE]


That's a good question since that's the ratio I want, and I hadn't heard about non-Ford gear sets giving problems. If that's true, then does Ford carry a 4.10 set for our axles through the parts dept.?

 

I have been taking it pretty easy with my HD since I got it (they come from Ford with 4.10 gears) until today when I really needed to punch it to get into traffic. Have to say that the 4.10's are noticeably better than the 3.73's. Still if I were changing over anyway I would go with 4.30's or 4.56's.
I am still trying to find a Super Duty with factory 4.30 gears and a 5.4 to take for a drive, just to see what kind of rpm's you get running down the highway.

For the record I have had an 02 with 3.73's, an 04 with 3.55's, an 06 with 3.73's and now the 04 with 4.10's. I ran the 02 with stock size tires, the 04 with both stock and oversize tires, the 06 with stock size tires and the 04 HD has oversize tires. Notice that I am saying "stock size" since the only truck I even ran on OEM tires was the 06 and that was for about 1000 miles.

Unfortunately my truck is an XL version and therefore does not have a tach so I really have no idea what rpm's I am running down the highway. Guess one of these days I should look into an aftermarket tach.

Check around where you live for a reputable gear shops and go and talk to them. It is not just a matter of swapping in new gears, they must be properly set up as well. A gear shop owner where I live was very adamant about the fact that he has had mechanics over the years who were very good at setting up differentials and others who never got the hang of it.

 

I am a little worried about someone swaping the gears out. We have a pretty reputable shop here in Huntsville, AL that works specifically with 4X4 trucks. I know this will be expensive but it is still cheaper than a new truck.

I guess I would certainly consider the 4:30 or 4:56 gears. My driving is mostly city with a few jaunts down the highway at 80 MPH. I take one 800 mile trip on the highway a year. If 4:56 or 4:30 gears wouldn't kill me I would take those. Will the front diff take those gears without modification?

It would be nice to have take off power so I could make guys with a bigger engine give me that confused German Sheppard look!

 

jeez, True Blue, don't you know a 4.6 couldn't pull a greasy string out of a cat's...well...you know. jk


Regarding the gears, I would think the 4.10 would be the way to go...I am lucky in that I only have a 2WD and don't have the major issue with you needing two sets.

what type of diff does the fords use up front? And are they engine-dependant like the rear diff? (8.8 for the 4.6 etc etc)

 

LOL, I know the 4.6 is weak but at the time I got it I thought I would just be running back and forth to work in it.

The front end is a Dana 44. I believe it is the same no matter which engine you have.

 

my brother has 4:56 gears on his F150 with 22in rims....quite a bit of torque. The truck is lowered so it does ride very differently but anything from 3:55's to 4:10's is not going to be worth the money. I would go with the 4:56 gears.

 

I had a lightning with 4:10 gears and it was fine on the highway. I just wonder how far my truck would wind out at 75-80 with 4:56 gears.

Does anyone know the final drive of the transmission so I can figure this out?