Nitpicky time. Is it 3.54 or 3.55?

[Buckdog]

Has anyone had their rearend apart and counted the teeth on the pinion and ring gear? I would like to know exactly what the ratio calculates to. I see both of these ratios a lot on this board in reference to the same readend, and it kinda bugs me not knowing which is correct.

 

[Buckdog]

Oops. I mean rearend.

 

[Big White Beast]

Take your pick............

39 teeth on the gear and 11 on the pinion. The math works out to

3. 545454545.



So if you take it out 2 it's 3:54. If you round up it's 3:55.



I prefer the 3:73.



Garrett

 

[Lsfarm]

I'd like to know

I'm not concerned about the . 01 But I am curious if our dodge trucks have the normal [in the past] slightly higher [lower numericaly] front ratio compared to the back??



Any of the 4x4 trucks that I've owned and checked out had for example 4. 10 front ratio, and a 4. 11 rear ratio.



I was told that this is so that the front axle tends to pull the truck around like a FWD and keeps the rear axle from pushing the front around turns in poor traction situations.



I do feel the gears bind some when I have 4WD engaged on good surfaces so I am assuming that the above is still correct for our Dodge Ram trucks.



Anybody know for sure??



Just curious



Greg L

 

[RustyJC]

I thought it was 3. 54 for the Dana 80 and 3. 55 for the Dana 70.



Rusty

 

[mongoose]

about the question about the difference in the front and rear gear ratio. In Mud Racing, the general rule is the front should be 5% higher than the rear. This is to help pull the truck straight. In my truck the 5% works out to 4. 88's up front and 5. 13's out back. I don't think that the 4. 10 to 4. 11 is really going to be noticable in the majority of circumstances. I'm not sure about the new trucks but i was thinking the difference in the older trucks was because of the dana front and corporate rears.

 

[Mopar-muscle]

for as long as chrysler has had Dana and there own rears its been 3. 54 in a Dana no matter the application , 3. 55 in everything else no matter the application .

 

[fj40charles]

I don't see how . 01 (3. 54 vs 3. 55) will make any difference at all.

This is like splitting hairs and will not make any difference at all. I would consider tire pressure differences between the front and rear a bigger factor.



Charles

 

[Todd T]

on the 01 trucks it says 3. 55 on the sticker that is in the glovebox.



BTW they moved it from under the hood like the older trucks had.



EDIT: all fixed, see Sig \/

 

[Ramboy]

My sticker under the hood says 3. 55 for my truck.

 

[Racechaser]

3:55's in my glovebox

 

[klenger]

I don't think there is any combination of ring and pinion gears that would provide a 3. 54 vs 3. 55. Based on the numbers that Big White Beast provided, if you increased the ring gear by 1 tooth, the ratio would be 3. 64 and if you decreased it by one tooth it would be 3. 45 There are only so many combinations available.

 

[fest3er]

Originally posted by klenger

I don't think there is any combination of ring and pinion gears that would provide a 3. 54 vs 3. 55. Based on the numbers that Big White Beast provided, if you increased the ring gear by 1 tooth, the ratio would be 3. 64 and if you decreased it by one tooth it would be 3. 45 There are only so many combinations available.

71:20 would yield 3. 55. But those gears might be a bit large for our applications.



Proper mathematic rounding yields 3. 54. But, as we all know, marketing math has its own defining theories. That is, 3. 54 becomes 3. 55, 30. 00 becomes 29. 95, and 48,000 becomes 47,500. I imagine this is because we the people are a bunch of idiotic dolts who believe that anything that's printed *must* be true.



Fest3er



Fest3er