I would like to know if any of you have changed out the 3:55 ratio to a more tow friendly 3:73 in your 4.6L F150? I have the FX2 Super Cab 2wd with factory 18" wheels & 3:55 axle and as I stated in another post. I was not very impressed with it's towing ability. I wonder if the lower ratio would give me a lot of help towing for the money it will cost to change it out? I realize that I could suffer in the gas mileage dept. a little, but it sucks gas anyway and that is not of a major concern to me. A slight drop in mpg is acceptable. Please let me know your thoughts. I already tried the Edge programmer in setting 2 and I was not really impressed by the changes it made by itself. I had rather not use the setting 3 due to 93 octane requirements. I actually looked into trading the truck for an identical unit with the 5.4L, but have yet to find one and they basically don't want to give any kind of decent trade allowance anyway. Thanks

 

Skip the 3.73s and go for 4.10s. Seriously.

 

IMO, you should just go to 4.10's if you are considering any kind of gear swap. I suspect your tires are around 32" tall (275/65/18)?? That's just a tad taller then my 265/75/16's..

Where is it that you feel the lack of performance while towing? Is it pulling the grades? Cruising down the hwy? City driving?

Towing is always going to be a series of compromises you have to deal with no matter if it's a little 4 banger towing a utility trailer or an F350 BBD towing a 15,000 Toy Hauler....

I have the 5.4 with 3.55 gears and tow a #5000 TT. I wish it had the 3.73's, but I don't think I'd get any real 'gain' for the $1500+ it would cost to do such a change in my case..

IMO, the 4.10's are going to help you most on your 'city' towing conditions and when going on the on ramps to the hwy. Once you are up to speed, then that's where the compromise comes into play.... You either have to have enough 'power' in your 4.6 to be able to hold OD, or you will still be stuck in third, but now pulling more rpms to cruise at say, 60 mph.. Even on the grades, your 4.6 will need the power to hold third gear longer to make the grade, or you will still be in second, pulling more rpms to maintain your speed...

The only thing me or anyone else can't gauge is YOUR towing performance expectations... While I feel I'm doing fine with my towing setup, you might drive it and think it SUCKS! The only difference there would be our individual performance expectations... I might drive your setup and think it's fine.... It's all in what YOU want your truck to do..

If you 'expect' to be able to keep up with the BBD's (Big, Bad Diesels) on the grades, then stop right now and go out and buy yourself one, because that's the only way you are going to get that kind of performance... No way you can make a 4.6 or even a 5.4 compete with that!

How about this.... When I was a kid back in the '70's, we went camping all the time. We had a 1976, 27' TT and towed it with a 1971 F250 "Camper Special"... We also had a slide in camper (no cab-over part) where my sister and I would ride (we could stand up in it and had 6' bunks on either side and a real "ice box" fridge!). On the grades, Dad had that 390, C6 auto in FIRST gear with his foot to the floor and we were going 25 mph!! And he thought it was fine at the time!! That's what everyone did back then! We were even passing the old station wagons towing the same size TT that were only going 20 mph!

Anyway, I digress, so I guess all of this boils down to is 'where' do you want the see the most performance gain??

Mitch

 

I agree, I have 3.55's and when I swap its going to 4.10's. They say you should always go up at least 2 ratio's to make the difference with the money

 

When I had my 1999 4.6 F-150, I was going to swap from 3.55s to 4.10s. Instead, I traded for something with 3.73s...

 

@ Zairman: & double the torque

3.73 is only 5% shorter gearing. 4.10 is 15% shorter. Gears cost the same, about $500 installed for your 4x2. The 4.6L likes to sing, so 4.10 woudl be much better if you want to make any swap. You proably would not even notice 3.73.

 

i'd love to throw some 4.10 gears in my truck instead of keeping the 3.55's. 4.10's are much better especially for the 4.6. you will notice a pretty good torque difference.

 

I get tired of the truck dropping out of OD when I see a slight hill when towing. I never tow much above 65mph and the weight is around 2,500-3,000lbs for my pop-up loaded including passengers and gear. I have also been looking at getting into quarter midget racing for my son and I want a 16'x7' enclosed v-nose tandem trailer for it and the stuff we need for race day. I figure that I would have around 4,500lbs there loaded including passengers. The v-nose will deffinitely help better than the traditional flat nose trailers I am sure. I hate that I am buried in my truck, but $12k ain't gonna buy a $32k truck regardless of what the fuel cost are and I will just have to keep it and make do. I still owe twice the trade in value as we speak! Thanks for the replies guys. What kind of fuel mileage do you think the 4.10's will give? LOL

 

u should always go up 2 from where u r now. however. if you ever decide to go any bigger on tires, or level, or lift. go with 4.56 gears, then you are covered up to a 35 inch tire, plus all the other benefits, towing, off roading, less wear and tear on tranny and so on

 

Not going to make that much difference dropping in and out of OD. My trailer is a bit larger, but didn't make that much difference. I just pull with the OD off. If I see that there is going to be a lot of flat in front of me I punch the button and let it shift into OD.

It's gonna make about 2 mpg less when not towing.


I went from 3:55 to 4:11 about 6 months ago. Just in time for gas to go out of sight.

Steve

 

Geeper,
My '02 had the 3.31:1 gears, and I swapped them out to 4.10:1. nice towing abilities. I get between 12-15 mpg. Great for in town driving too. I pulled a 8'x18' cargo trailer cross country with the truck and it done fine.
While you are in there, if you don't have a limited slip, that would be a great time to put one in if you decide to change gears!

 

I've pulled a 20 ft. car hauler with 4.10 gears and with a 5.4 in Florida and I have to lock out OD the whole time.

 

Heck, my truck will downshift out of OD on slight hills when I'm towing my little 4x8 utility trailer with only #1000 in it! It'll do the same on slightly longer hills when the truck is empty too...

Will you be able to hold OD while towing the #4500 V nose in those same situations, even with the 4.10's??? Doubtful IMO..

Going to the 4.10's is going to net you around 300 more rpms while in OD going between 60-65 mph. Third gear (1:1) is going to net you around 400 more rpms while going between 60-65 mph.

So, it sounds like your performance expectation is to be able to tow while in OD??

I live in the NW and there is not really any 'flat' areas, so I'm always going up or down some kind of hill. I tow my TT all over the state, crossing the Cascades, or heading to the coast. Most of the time, I'm running with the OD turned off and running in third. With the 3.55's, I'm pulling between 2200-2400 rpms going 60-65 mph. Actually, that's about perfect for my engines power range, so it's not hurting it any... I've got 188,000 miles on the thing too!

It's a compromise when towing, so you have to decide what you are going to compromise on. I decided that even thou I tow a #5000 TT, it only equates to about 3000 miles a year, if that. I drive it unloaded well over 13,000 miles a year. While the 4.10's would probably give me a little better towing performance, do I want to deal with them 78% of the time??

On another post, I was asked if I were 'given' the chance to get 4.10's for free, would I do it? I said in that post, "In a heartbeat"... I'm beginning to rethink that response now.... I like my 3.55's and if it causes me to drive in 3rd gear for the times I'm towing, well for me, that's my compromise for now!

I can run in OD while towing, as long as it's flat and no head wind... I still get around 10 mpg while towing, regardless if I use 100% 3rd gear, or add some OD time to the equation... Does not really matter for the most part of running in OD, unless I was able to do it 90% of the time IMO.

I do like my 15-16 mpg average for my daily driving with the truck, and the majority of that daily driving is on the hwy...

So, no right or wrong answer for ya on going to the 4.10's in your case... You just gotta decide what compromise you are willing to deal with!

Mitch

 

has anyone tried for 3.90's

 

a guy had me put them in a mustang one time but he wasnt very satisfied because he didnt notice as big of a change as he did with his silverado which he put 4.10's in. so he says anyways. i thought it hauled a** compared to the 3.08's it had.