Truck info: 05' 5.4L 4x4 with 3.55's and 35" tires, Programmer, and Magnaflow

After much debate between 4.10's and 4.56's I decided to go with the 4.10's because I do a lot of hwy driving and I didnt want my rpms to high when cruising.

I just recenlty upgraded my 3.55 gears to Precision 4.10's. (BTW Ford Racing Gears are actually Precision Gears and are changing to Motive.)When I put 35's on my truck the stock 3.55's just wouldnt turn them over and it was constantly gear seeking on inclines or trying to accelerate at hwy speeds.

The 4.10's made a HUGE difference. The truck now accelerates and maitains speeds the way it should. After breaking them in I have had a chance to open it up and see what they could really do. I floored it from a light one night and left about 5 feet of rubber it was awesome!! I am averaging 14 mpg in the city and 16.5 on the hwy at 80 mph, if I could manage to drive 70 the mpg would probably be around 17.5. The RPMs for HWY driving are @ 70 MPH 2000 RPMs and @ 80 MPH 2300 RPMs and @ 90 2500 RPMs.

For those that want to know about Pricing. After all said and done gears, install kit and labor cost me $1500.00.

I think it was well worth it, and I am more than happy with the upgrade. I would definitely recommend gears to anyone who looses power due to increased tire size.

Doug

 

Cheers Doug!

I have some 4.10s on order with a local shop and will be getting them installed in a week. My 5speed runs to 3.55s right now with 255/60/R16s and my new size tires will be 235/80/R16s for winter tires and 285/60?R16s for summer.

Is the break in short as 100 miles or more?

 

Just about everyone that I talked to said that you should take it easy on them anywhere from 500-1000 miles. After break in it is also recommended to change the fluid in the rear diff. I waited just over 700 and let me tell you what it was hard to do. I wanted to put my foot into it so many times. It is well worth the wait though. Then you know you are breaking them in correctly and it just builds the anticipation.

 

I was given the same advice.

 

What are you guys paying to have 4x4's done?? I was quoted around $1500.

 

Damn. 2300 @ 80? That's it? Is assume it's because of your tires that the rpm's are lower. My truck at 80 runs 2000 or 2100 with the stock 18's.

 

Gears don't affect rpm as much as many folks think, at least not to the extent that they did back in the day.

When I tell people that I have 4.10s with my street-size tires they automatically think that my truck is screaming at redline going 60mph. Which isn't the case at all.

These trannies have a wide spread of ratios.
In my case, I started with 3.31s and went to 4.10s.

The gains in drivability for these heavy trucks are well worth it.
Just a little bit of extra torque multiplication goes a long way.

 

good to hear! i have the same sized tires and RPMs as you. dont you love your ability to still be economical and go fast on the freeway?

one note though: ford racing gears are richmond. precision does not make anything for ford

motive is absolute crap. i doubt ford would ever accept anything from them.

 

I love my new gears, definitely a good upgrade.

I got my gears from Racer Walsh Inc. a Ford Racing dealer out of Jacksonville Fl. They told me that Ford Racing currently uses Precision Gears and will be changing to Motive gears. I'm just going with what I was told by the guy from Racer Walsh and figured I would share. Now if it's 100% accurate or not I couldn't tell you since I am only going off what he told me.

 

My truck has been at the shop for 2 days now. Do they typically drive the truck a few miles to calibrate? I hope its not me who needs to notice if the gears whine.

On another note I cant wait to get the 32s on and feel the difference.

 

i know this is about 4.10 gears but does any one know how much of a diffrence in fuel econonmy and hightway rpm is 4.56 with 35's