i always heard 50 miles. plus its like breaking in an engine, everyone has a different opinion.

 

thanks for the info, the tires are on there is slight rubbing at full lock, but actual measurement comes to a 33.5 mounted so far im pleased ive only driven 12 miles so far. ill decide in the next few days if i want to re-gear. once again thanks for all of u guys help and info.

 

Klitch: I hear ya buddy. you know what they say about opinions.......

Mpresme: NO problem buddy. I hope i helped.

 

35's will def be the largest tires I will ever run. Largest towing application would be a 25ft trailer (hardly ever) and around town. I'd say mixed driving habbits (both in town and highway 50/50).
What would the performance increase be with the 4.56? And cost....... how bout cost for the gears and install? With that setup, and tire size there wouldn't be any expected wine would there?
What are some of the choices for manufacturers of gear setups?
And finally, ..... whats the stock ratio on my 06' FX4? (and does it being a
4X4 play into modifying the gears? Adversely affecting any related systems?)
Thanks tnsilverfx4

Mike

 

Mike,
If you will be doing about 50/50 and possibly towing, I would run the 4.56's. I would have done 4.56's if I wasnt going to go bigger. Your truck will feel like it did stock before the 35's, with more pep. It will not slug around and you will feel the power as you shift gears. Gear whine is a result of poor setup and in some cases poor gear choice. I went with Yukons which can be kind of pricey depending on where you get them. Ive only got my rear diff. complete at this point, but will go with yukons again in the front diff. There are many different choices. Go with what you feel is right. Yukons and Precisions seem to be the preference on here, but motives also have satisfied some people. For 4.56's Ford also makes gears for our trucks. You might want to look into those as well. Cost will really vary depending on where you look. I would expect anywhere from 700-800 in parts for yukons, with labor and tax really being the variables. Remember, you have to do both differentials. You dont have to do them at the same time, just DONT use 4 wheel drive. You will make your transfer case explode=add a couple thousand on the gear cost. Your stock ratio will be either a 3.55 or 3.73. Crawl under your truck and look at the rear axle. A little tag is hanging on there. Your ratio will be listed.

Pat

 

Awesome info Pat
I've read alot about people commenting about "sluggish" performance after upsizing with their leveling kits to 35's. Many suggest a tuner (which I will be getting also) but some comment it still didn't take up all of the slack. It sounds like a good combo with the gears AND tuner to wake up my truck, and I can tell the tuner the gear ratios I would be running as well, correct?
And the price you quoted........ is that JUST the rear end? Or total job front and rear (parts at least) I have the blessing of best friend mechanics with keys to their mom and pop shops. So knowledge, tool accesibility and a helping hand are all not a problem to get the job done free of labor and taxes

 

If you are going to get a tuner regardless, try tuning it first. See if you like it. you might decide you dont want/ need gears. Then if it turns out you still want them, and you were going to buy the tuner anyway, you arent out a couple hundred additional dollars. yes the tuner SHOULD be able to reprogram ratios. I say should because not every tuner can calibrate all ratios. Some cutoff at 4.56 (Which wouldnt really affect you, but I should mention it anyway).
If you have the hookup, (Friends with experience and a shop) there is no reasion why you cant get this job done (Front and rear axles) for under a grand. Thats R&P's ($600) Master Install Kits ($300) Oil & Miscellaneous
($100)
Im highballing on some of that, but that estimate is with top end parts.

 

4wheelparts is having a sale on gear packages right now, up 25% off.

Do 4x4s have the 8.8in 31 spline rear spline:31, or the 9.75in long rear spline:34 axles?

- NCSU

Edit: Searched around and it found that the 5.4L comes with the 9.75in, is it Long rear spline:34 or short rear spline: 34? I'm thinking it's the long...

 

Long

 

Thanks again Pat!

 

If I were to order one of the gear packages on 4WP and then take the front/rear diffs off myself and take them to someone to install the gears, how much would that cut down the labor costs do you think? I could do most of the work except for the actual setting of gears.

 

The rear axle, probably nothing because they can change the gears on the rear with the axle on the truck. They just remove the cover and take out the differential.
The front however, i dunno. Call the shop you are looking at and ask. Remember, you are paying for the shop's time. If it makes it that much easier for their technicians to setup the gears it might help.
Let us know

 

generally speaking the front diff is the worst to get to, so if you cut out the labor time to just get to it that'll probably save a few hours per book.