JHG

One member told me my truck would drive like a dog with bigger tires and 3.31 gearing. Maybe not, but I definitely feel the difference and want the spunky 3.5 TT pick up from the stock set up back. I don't tow, live in SF with no hills within 500 miles, screw 4X4, sizable amount of highway miles, running 285/60 20's now and would like to go to 285/65 20's next year or whenever these tires wear out. I picked up front and rear 3.55 yesterday and was going to get them installed Monday. All the calculating charts I used consider tire size only and not weight. They all seemed to confirm that the 3.55 would be right at stock ratio with the 285/65 20's. but again none required weight. Thoughts?

MGD

Hi.

I think I would have chosen 3.73's, meseff. And I did try, but coon't get 'em in me config.

-not much of a % jump from 3.31-3.55
-need to compensate for mass increases (static & rotational), not just loss of mechanical advantage
-what if you ever decide to go with even larger/heavier rolling stock?
-I like a fast truck .. so don't mind ol' Bubber, lol

good luck!

Cheers
Vladsky

JHG

yeah, I do to. Lol

Halfshell1

3.73

qarl

Since I don't have a 150 yet... does the ECM or TCM have programming that controls the shift points?

I know my 2012 Mustang GT had a computer that controlled everything... when you swapped out the rear-end with different gears, you needed to get the engine tune flashed to adjust the shift points, otherwise the automatic tranny felt odd and shifted in weird spots.

Just asking as an FYI?

JHG

I had the same concern, when I picked up the parts Ford said they do not have the ability to access or change this (they also said this after I asked them to do the same after I installed the larger wheels and tires). The guys doing the gear swap said he has access to one that will be able to make the adjustments. I'll triple check in the morning.
Thanks

qarl

Please post what you find out!

plains

I have a screw with 285 65 20 and 3.55 and I have all kinds of jam

tomt5078

From what I have red this will cost $$$$$, so how much is this going to cost you?

JHG

I'm $650.00 in now, Ford wanted $1,400. I'll let you know tomorrow but I'm guessing $600? You where that gets you though.