Computer question: After Re-Gear
Thread Starter
|
Elder User
Joined: May 2003
Posts: 540
Likes: 0
From: North Florida
Computer question: After Re-Gear
I know from previous experience in re-gearing newer (think 1999 til now)GM's, that once you change the ratio, the dealership can do nothing for you. I tried on 2 different Suburbans and a Tahoe. The computer device they use (Tech II) says "NO". It is because GM attaches the ratio given at the factory to the VIN. Tech II won't let mechanic at dealership change the ratio to something different than what is attached to that VIN. I stood and watched the machine tell the tech "invalid ratio" numerous times. I had to buy aftermarket programmers to set my own ratios.
So... my question is, "does Ford play this game also?" If I re-gear, will I go to a dealership just to be told that they can't help me because the computer says MY VIN can only have the ratio it came with? Or does Ford allow you to change gears and then reprogram?
Those who have done it, or any Techs here please advise. Don't want to have to buy a programmer to set my R&P ratio.
Thanks a million!
James
So... my question is, "does Ford play this game also?" If I re-gear, will I go to a dealership just to be told that they can't help me because the computer says MY VIN can only have the ratio it came with? Or does Ford allow you to change gears and then reprogram?
Those who have done it, or any Techs here please advise. Don't want to have to buy a programmer to set my R&P ratio.
Thanks a million!
James
Cargo Master
Joined: Oct 2006
Posts: 2,097
Likes: 5
From: chicago northwest suburbs
No. Ford uses the speed sensor at the diff. So as long as you have the factory size tires the speedo will stay unchanged. I don't know if Ford can chage the speedo due to a tire size change? I went from 3.73 to 4.30 with no issues.
Thread Starter
|
Elder User
Joined: May 2003
Posts: 540
Likes: 0
From: North Florida
Just to understand: The speed sensor is located in the rear diff housing... so it senses the speed from the rotation of the ring gear... so changing the pinion ratio to the ring gear wont throw it off?
Am I close on that?
Thanks!
James
Am I close on that?
Thanks!
James
Cargo Master
Joined: Feb 2011
Posts: 3,450
Likes: 13
From: Forest lake minnesota
That is correct.
Thread Starter
|
Elder User
Joined: May 2003
Posts: 540
Likes: 0
From: North Florida
Cool, thanks guys! 
Now, next question for those who have done it: will spending the money to have my gears swapped "really" make much difference in towing ability/comfort if I go from 3.73 to 4:30 with 285/75/16 tires? Obviously don't want to spend the jack to find out that it was a waste of money.. and not real sure I want to make the jump to 4.56.
Thank you again!
James
PS: I know "search is my friend". But I haven't found an exact match to my situation... 3.73 with 285's to 4:30 with 285's.
Now, next question for those who have done it: will spending the money to have my gears swapped "really" make much difference in towing ability/comfort if I go from 3.73 to 4:30 with 285/75/16 tires? Obviously don't want to spend the jack to find out that it was a waste of money.. and not real sure I want to make the jump to 4.56.
Thank you again!
James
PS: I know "search is my friend". But I haven't found an exact match to my situation... 3.73 with 285's to 4:30 with 285's.
Cargo Master
Joined: Oct 2006
Posts: 2,097
Likes: 5
From: chicago northwest suburbs
Having gone from 3.73-4.30 it is a night and day difference in towing. it makes the X feel much healthier when towing, it`s not being held back. running 285`s ( I have them) will not change much. they are approx. a 1/2 inch taller which equates to a 1/4" height difference, but they are wider. I can honestly say that going to 4.56`s would not be out of the question especially if towing heavy. part of me wishes I had gone to a 4.56, but I haven`t had an issue yet. I`m towing a 9000lb 11.5ft tall 35ft TT, so it gets a work out!
Trending Topics
Thread Starter
|
Elder User
Joined: May 2003
Posts: 540
Likes: 0
From: North Florida
Thanks Guys!
I "think" Ill stay conservative and go with 4.30's when it is time. I only tow about 6000 lbs, but it is enough with the TALL front end to give the Ex a workout in mountains of Georgia and Tennessee.
Your input has been greatly appreciated and good stuff I couldn't find in a search.
James
I "think" Ill stay conservative and go with 4.30's when it is time. I only tow about 6000 lbs, but it is enough with the TALL front end to give the Ex a workout in mountains of Georgia and Tennessee.
Your input has been greatly appreciated and good stuff I couldn't find in a search.
James
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Post Fiend
Joined: Mar 2009
Posts: 11,798
Likes: 14
From: Mt. Shasta California
Right, the sensor ring is "locked" to the rear wheels so only a tire size change or a sensor on the transmission would throw it off.
FTE Chapter Leader
Joined: May 2006
Posts: 11,273
Likes: 99
From: North Dakota
Way I figure it is if the 4.30s where available stock, might as well go lower if the tires are taller than stock. That way it performs as good or better than a 4.30gear/265 tire ex.
I run just shy of 3,000 rpms with 4.88s and 285s at 80 mph if I remember right. It pulls like mad. Even my Dad that has a 6.4l diesel was impressed how long it would hold OD pulling my camper and ATV trailer at 60 mph.
I run just shy of 3,000 rpms with 4.88s and 285s at 80 mph if I remember right. It pulls like mad. Even my Dad that has a 6.4l diesel was impressed how long it would hold OD pulling my camper and ATV trailer at 60 mph.
Bleed Ford Blue
Joined: Apr 2009
Posts: 13,578
Likes: 157
From: Anchorage Alaska
thats the reason i'm going to go with 4.56's and 31.6" tires..more TQ
Super Moderator
Joined: May 2004
Posts: 29,380
Likes: 118
From: Central Coast of CA
Stewart
Bleed Ford Blue
Joined: Apr 2009
Posts: 13,578
Likes: 157
From: Anchorage Alaska
splitting hairs, ok Multiplying the TQ you ALREADY have and using it more efficiently.