4.56 Gear Question
#81
08-25-2007, 03:02 AM
RE: 4.56 Gear Question
Hey Ram Air
To get off track a little bit I been looking to go to lowwer gears In my 3rd Genaration Dodge My self Dont laugh to hard Ya I made the Mistake by Buying the 3.7 V-6 for MPG.
I have The 6 Speed Trans In it with 3.21 gear set I konw they are freeway flyers They suck Do what gear set would you put in this truck 2006 Dodge Q-Cab 4X2 3.7 V-6 I do mostly HWY driving 70 + MPH round trip to work and back 65 Miles per day + 5 days a week drive 200 to 300 miles on the weekends, Haul 400 to 700 lbs once a month or so it's my family hauler.
I like to get ride of some of the lazyness I know it will never be a fast truck But where I live there' lot winds and rolling hills that kill the truck 6th gear is useless most of the time around here besides I tired of alway down shifting all the time it should do better at HWY speeds been able to hold it's speed.
I been looking at 3.90's or 4.10s what do you think which way I should go and try to keep some MPG out of the all powerful 3.7 V-6 Ha Ha.
To get off track a little bit I been looking to go to lowwer gears In my 3rd Genaration Dodge My self Dont laugh to hard Ya I made the Mistake by Buying the 3.7 V-6 for MPG.
I have The 6 Speed Trans In it with 3.21 gear set I konw they are freeway flyers They suck Do what gear set would you put in this truck 2006 Dodge Q-Cab 4X2 3.7 V-6 I do mostly HWY driving 70 + MPH round trip to work and back 65 Miles per day + 5 days a week drive 200 to 300 miles on the weekends, Haul 400 to 700 lbs once a month or so it's my family hauler.
I like to get ride of some of the lazyness I know it will never be a fast truck But where I live there' lot winds and rolling hills that kill the truck 6th gear is useless most of the time around here besides I tired of alway down shifting all the time it should do better at HWY speeds been able to hold it's speed.
I been looking at 3.90's or 4.10s what do you think which way I should go and try to keep some MPG out of the all powerful 3.7 V-6 Ha Ha.
#82
06-29-2008, 06:21 AM
RE: 4.56 Gear Question
ORIGINAL: AIR RAM
Its all math guys... and math only has ONE right answer. SO dont take my word for it... although I have done the math.
You have a .67 over drive... if you want the overall gear ratio... meaning the ratio as if you had a 1:1 ratio like in a th400 NON overdrive trans....
transmission gear x rear gear = overall gear ratio
.67 x 3.55= 2.37
.67 x 3.92= 2.62
.67 x 4.10= 2.74
.67 x 4.56= 3.05
Now if you would like to see how much your RPMs change here is the formula:
SPEED x overall gear ratio x 33.6 / tire hight = RPM
You do the math on your own.... I have beat this into the ground so many times I already know the answer... Im driving it every day! But I would like to know when a 3.05 gear became too steep? As long as I could remeber a 3.05 gear has been refured to as a GRANY gear... and with 4.56 it is when in overdrive but when your not in overdrive you get the 4.56's you grew up fearing... AND THATS A GOOD THING .
Now consider the tire hights we have now days... you have much larger tires that where NEVER imagend back even in the early 90's... for as long as I could remeber the 15" rim was as big as you could get... and 26" tall tires where the tallest tire you could find... so ANY experience with 4.56's back when there was NO overdrive and short tires is worthless in this equation.... you need to take into consideration... vehicle weght, tire diameter, overdrive gear, and rear gear to make an informed decision on what is best... you can not just look at the rear gear and use old math.
SPEED SAFE, AIR RAM
Its all math guys... and math only has ONE right answer. SO dont take my word for it... although I have done the math.
You have a .67 over drive... if you want the overall gear ratio... meaning the ratio as if you had a 1:1 ratio like in a th400 NON overdrive trans....
transmission gear x rear gear = overall gear ratio
.67 x 3.55= 2.37
.67 x 3.92= 2.62
.67 x 4.10= 2.74
.67 x 4.56= 3.05
Now if you would like to see how much your RPMs change here is the formula:
SPEED x overall gear ratio x 33.6 / tire hight = RPM
You do the math on your own.... I have beat this into the ground so many times I already know the answer... Im driving it every day! But I would like to know when a 3.05 gear became too steep? As long as I could remeber a 3.05 gear has been refured to as a GRANY gear... and with 4.56 it is when in overdrive but when your not in overdrive you get the 4.56's you grew up fearing... AND THATS A GOOD THING .
Now consider the tire hights we have now days... you have much larger tires that where NEVER imagend back even in the early 90's... for as long as I could remeber the 15" rim was as big as you could get... and 26" tall tires where the tallest tire you could find... so ANY experience with 4.56's back when there was NO overdrive and short tires is worthless in this equation.... you need to take into consideration... vehicle weght, tire diameter, overdrive gear, and rear gear to make an informed decision on what is best... you can not just look at the rear gear and use old math.
SPEED SAFE, AIR RAM
I just want to tell U that when U write I pay attention as I always am informed real well with ur writings.
But I needed to mention this post, per se,cause it was real funny reading.
You said that math has only 1 (Correct)answer. Correct you are...
But in the same breath (post,lol) U stated that " U can not use "old" math"
Well if that isn't an oxymoron then nothing is. lolol
But I get Ur point, maybe this is what confuses some ppl my friend.
X = X, PERIOD. NO MATTER WHAT DIDGITS U USE.
Ppl are using formulas that are as old as man kind, which still merit proper answers but they are not keeping up w/the newer (combo) numbers of today.
i.e. Taller tires, lower overall gear ratios in transmissions etc..
Like I enjoy telling ppl.
There is no such thing as "I'm a little pregnant"
Note:
I came to this topic doing a search to find out what will I need if I changed my rear gears.
What will I have to do w/the front gears.
I have a 20024x4 5.9l AUTO, Dodge Ram and I think I found out now that I do not need to do anything to the front ones...
Pls let me known if I am not mistaken with this.
I "believe" my gears should be 3.92 as they are stock now.
Thank U kindly for all and any support
#83
06-19-2009, 04:58 PM
#84
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