Question on 456 gear
12-03-2011, 09:56 AM
#1
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Question on 456 gear
Anyone have any opinions on the 456 gear on a 2010 FX4 with 35 inch tires? Truck also has a 6 inch BDS Lift. Is it good, bad, not necessary?
12-03-2011, 11:58 AM
#2
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IMO, it would be too low for general driving.
12-03-2011, 01:03 PM
#4
If type in "axle ratio calculator" into google you will get several results. On any of these calculators the result is to get your final drive ratio back to as close to stock as possible. I used this one for the following results: http://www.4lo.com/4LoCalc.htm
Then the second calculator: " Find new Gear Ratio with new tire size"
SO.... if you put in 35" for new tires size, and 32" for old tire size, and 3.73 for old ratio you get 4.08 as the new ratio. Very close to 4.10.
AND you put in 35" for new tires size, and 32" for old tire size, and 3.55 for old ration you get a 3.88 as the new ratio.
This will get your ratios as close to stock as possible. Remember the goal here is to get the engine rpms to return to their stock levels. Remember the higher the gear ratio(taller gear) the more acceleration and less top end you have at a loss of higher engine RPMS. Your engine torgue and horsepower are made higher in the engine power band but at a loss of fuel economy, it takes more gas for an engine to run at higher RPM's. You don't get something for nothing. These formulas do not factor the added weight of the larger tire however and this is a contributing factor.
If I was going to regear from my 3.73 when i put 35's on i would put 4.10 gears in and return to as close to stock as i can get. Using 4.10 gears probably wouldn't even require a speedo recal....
Then the second calculator: " Find new Gear Ratio with new tire size"
SO.... if you put in 35" for new tires size, and 32" for old tire size, and 3.73 for old ratio you get 4.08 as the new ratio. Very close to 4.10.
AND you put in 35" for new tires size, and 32" for old tire size, and 3.55 for old ration you get a 3.88 as the new ratio.
This will get your ratios as close to stock as possible. Remember the goal here is to get the engine rpms to return to their stock levels. Remember the higher the gear ratio(taller gear) the more acceleration and less top end you have at a loss of higher engine RPMS. Your engine torgue and horsepower are made higher in the engine power band but at a loss of fuel economy, it takes more gas for an engine to run at higher RPM's. You don't get something for nothing. These formulas do not factor the added weight of the larger tire however and this is a contributing factor.
If I was going to regear from my 3.73 when i put 35's on i would put 4.10 gears in and return to as close to stock as i can get. Using 4.10 gears probably wouldn't even require a speedo recal....
12-03-2011, 02:47 PM
#6
ETTYOCEO ®
Originally Posted by surelly09
If type in "axle ratio calculator" into google you will get several results. On any of these calculators the result is to get your final drive ratio back to as close to stock as possible. I used this one for the following results: http://www.4lo.com/4LoCalc.htm
Then the second calculator: " Find new Gear Ratio with new tire size"
SO.... if you put in 35" for new tires size, and 32" for old tire size, and 3.73 for old ratio you get 4.08 as the new ratio. Very close to 4.10.
AND you put in 35" for new tires size, and 32" for old tire size, and 3.55 for old ration you get a 3.88 as the new ratio.
This will get your ratios as close to stock as possible. Remember the goal here is to get the engine rpms to return to their stock levels. Remember the higher the gear ratio(taller gear) the more acceleration and less top end you have at a loss of higher engine RPMS. Your engine torgue and horsepower are made higher in the engine power band but at a loss of fuel economy, it takes more gas for an engine to run at higher RPM's. You don't get something for nothing. These formulas do not factor the added weight of the larger tire however and this is a contributing factor.
If I was going to regear from my 3.73 when i put 35's on i would put 4.10 gears in and return to as close to stock as i can get. Using 4.10 gears probably wouldn't even require a speedo recal....
Then the second calculator: " Find new Gear Ratio with new tire size"
SO.... if you put in 35" for new tires size, and 32" for old tire size, and 3.73 for old ratio you get 4.08 as the new ratio. Very close to 4.10.
AND you put in 35" for new tires size, and 32" for old tire size, and 3.55 for old ration you get a 3.88 as the new ratio.
This will get your ratios as close to stock as possible. Remember the goal here is to get the engine rpms to return to their stock levels. Remember the higher the gear ratio(taller gear) the more acceleration and less top end you have at a loss of higher engine RPMS. Your engine torgue and horsepower are made higher in the engine power band but at a loss of fuel economy, it takes more gas for an engine to run at higher RPM's. You don't get something for nothing. These formulas do not factor the added weight of the larger tire however and this is a contributing factor.
If I was going to regear from my 3.73 when i put 35's on i would put 4.10 gears in and return to as close to stock as i can get. Using 4.10 gears probably wouldn't even require a speedo recal....
12-03-2011, 08:38 PM
#7
Numerically HIGHER gears are a lower gear, which does exactly what you describe above. A 4.10 or a 4.56 is a lower gear then the OPs 3.73.
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12-03-2011, 10:10 PM
#8
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my gear was 3.73 and the shop that put on my 4.56 gear,6" bds lift said it would be back to stock with 35" tires would be no problem, the problem is my trans i have no reverse and all the ford dealers in the chicagoland area tell me my warranty would be voided if they have to look into the problem,i only have 3000 miles on 2010 fx4 it just sucks knowing that.
12-04-2011, 01:35 PM
#9
Originally Posted by willie01
my gear was 3.73 and the shop that put on my 4.56 gear,6" bds lift said it would be back to stock with 35" tires would be no problem, the problem is my trans i have no reverse and all the ford dealers in the chicagoland area tell me my warranty would be voided if they have to look into the problem,i only have 3000 miles on 2010 fx4 it just sucks knowing that.
