2014 and up gear swap

SouthTexan · May 26, 2015

drittal said:
EVIC is off if speedo is off.

Correct, and the odometer will be off too so even hand calculations are out of the question until the speedo/odometer is recalibrated.

TWILLIAMS9 · May 27, 2015

Decided to give the truck some gas today while getting breakfast, and it breaks the tires loose now pretty easily. So far very happy with the gear change.

loveracing1988 · May 27, 2015

Do you have a printout with the part numbers for the gearsets and the rebuild kits by chance?

TWILLIAMS9 · May 27, 2015

loveracing1988 said:
Do you have a printout with the part numbers for the gearsets and the rebuild kits by chance?

I'll have to look on my receipt.

drittal · May 27, 2015

TWILLIAMS9 said:
Yes so I'm getting better better mileage than what the EVIC says

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Worse. For the same engine revolutions you are going a shorter distance due to the numerically higher gears, but computer does not know that because your speedo, and thus odometer, are off.

TWILLIAMS9 · May 27, 2015

No my speedometer is saying I'm going a certain speed while in reality I'm going faster therefore I am traveling a further distance than what my trucks computer thinks it is going. My mileage is greater than what my truck thinks. Also my EVIC is saying I'm getting better mpg but in reality it is a little better than that!

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drittal · May 27, 2015

you could use some math to find the correction factor to change measured miles to actual U til you have your speedo corrected.

drittal · May 27, 2015

TWILLIAMS9 said:
No my speedometer is saying I'm going a certain speed while in reality I'm going faster therefore I am traveling a further distance than what my trucks computer thinks it is going. My mileage is greater than what my truck thinks. Also my EVIC is saying I'm getting better mpg but in reality it is a little better than that!

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You better check that. If you went to a numerically higher 4.56 gear, your speedo should be reading faster than you are actually travelling. Its the same as going to a smaller diameter tire.

TWILLIAMS9 · May 27, 2015

Already checked that. My girlfriend was on the freeway with me and set her cruise control to 66mph. I matched her speed and my speedometer was only on 58mph.

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drittal · May 27, 2015

Maybe i missed something. did you change tire size?

Soldier of The Law · May 27, 2015

He's on an 8" lift and 37's.

drittal · May 27, 2015

Then I'm assuming his speedo was off before the gear swap.

The gear swap with no other changes would cause the speedo to read higher than actual.

So 4.56 and 37" is still taller than 4.10 on stock.

regularcab2500 · May 27, 2015

You know, i find it funny that you think your truck was sluggish after the lift and 37s. Now obviously the height adds issues with aerodynamics vs a stock truck and the wheels are much heavier but.....

Stock tire size is 33.1" i think and assuming your 37s are 37":

33.1 / 37 = .895~
4.10 x .895 = 3.67 actual gear ratio

Also, after the gear reduction:

3.67 ÷ 4.10 = .895~
4.56 x .895 = 4.08

Just pointing out your effective ratio was just under 3.73 (which is what my truck has). Boy im jealous, i want 4.56s so bad lol. For the record i dont believe gear ratio effects the speedometer in any way.

TWILLIAMS9 · May 27, 2015

I knew my effective ratio was at 3.73 but it was much worse than our trucks stock with the 3.73. I test drove one before I bought mine. The added weight and aggressive tread of the tires and maybe the width slowed it down a little but it was the mileage that really suffered. The main reason for the gear swap was to make it easier on my truck pulling the trailer in the mountains. I believe it will help a ton. Added benefit of increased merge and use of my MDS again.

regularcab2500 · May 27, 2015

With your setup and needs i say you absolutely need those gears. The weight of the tires/rims has more to do with it than the overall size so it should take some of strain off the rest of your drivetrain too...as you know lol

TWILLIAMS9 · May 27, 2015

Yeah I'm actually sitting in my trailer right now getting it prepped. I'll take some pictures for ya'll.

Ratket · May 30, 2015

how u liking the gear swap so far?

TWILLIAMS9 · May 30, 2015

I like it a lot. Just still trying to take it easy most of the time to break these in. Gives me an excuse to drive the truck more.

TWILLIAMS9 · Jun 10, 2015

Here is my receipt for my gears.

loveracing1988 · Jun 10, 2015

TWILLIAMS9 said:
Here is my receipt for my gears.

View attachment 52433

There is nothing with part numbers on it?

2014 and up gear swap

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