Author Topic: ring and pinion  (Read 3946 times)

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kbar

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ring and pinion
« on: April 09, 2012, 06:43:41 PM »
I can't not seem to find what gear ratio I need to run with my dana 44 with 37" tires I am about to get. I looked at morris 4x4 and it told me like 4.27. And that doesn't make since. I looked somewhere else and I found like 5.49. I do have a 4 cyl YJ so I know I will need to gear high, I would like to be able to drive 65, does anyone know the optimum gear to run or can someone send me in the right direction please. Thanks!

Offline sharpxmen

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Re: ring and pinion
« Reply #1 on: April 09, 2012, 07:31:08 PM »
I can't not seem to find what gear ratio I need to run with my dana 44 with 37" tires I am about to get. I looked at morris 4x4 and it told me like 4.27. And that doesn't make since. I looked somewhere else and I found like 5.49. I do have a 4 cyl YJ so I know I will need to gear high, I would like to be able to drive 65, does anyone know the optimum gear to run or can someone send me in the right direction please. Thanks!
I'm going to assume you have a manual transmission

to have the ratio (speed at rpm) same as stock you can just calculate it and pick the closest one available
28'' stock tires
4.10:1 stock R&P ratio
37'' new tires

NewRPratio=(OldRPratio/stockTireSize)*newTireSize=(4.10/28)*37=5.41

not sure what the closest one is but if it's 5.49 sounds like that site had it right

you can go longer though to next size up (higher numerical ratio) but i woudn't go below as it would be a real dog.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
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Offline aw12345

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Re: ring and pinion
« Reply #2 on: April 10, 2012, 07:06:05 AM »
Unless you plan on running JK axles I think 5.13 is the highest ratio you can go.
I have 5.38 gears in my axles for my 4 banger and would have liked 5.86 alas not available for the axles I have. Swapped in a 6 speed trans also and that combo is closer to what I deem desirable
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

Offline FourbangerYJ

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Re: ring and pinion
« Reply #3 on: April 10, 2012, 07:58:19 AM »
I ran 37's for a couple years. I run 5.38's. Did pretty good, could of used a bit lower gear. But with my HP D44 front 5.38 is as low as I could go. The LP D44 can go to 5.89.

What axles are you running?
Scott~

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kbar

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Re: ring and pinion
« Reply #4 on: April 10, 2012, 08:35:02 AM »
I think I'm gonna run 5:38s. I got a Ford Bronco's Dana 44 and a Ford 9 inch(I got a good deal on em). So I'll be able run about 65 on the highway with those gears?

Offline FourbangerYJ

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Re: ring and pinion
« Reply #5 on: April 10, 2012, 10:37:42 AM »
I think I'm gonna run 5:38s. I got a Ford Bronco's Dana 44 and a Ford 9 inch(I got a good deal on em). So I'll be able run about 65 on the highway with those gears?

On the flat yes. Even faster. It's not gonna be a speed demon but I was able to maintain 65-70 on the flat sections without much effort. The hills will still dog you down some.
Is yours a stick or auto?
Scott~

Using tools you have not used in a while is like shaking hands with old friends. :nod:

kbar

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Re: ring and pinion
« Reply #6 on: April 10, 2012, 11:35:14 AM »
AX5, ok so I have been trying to find a Ford 9inch 5:38, well I cant find one. The only gears I can get to match is 5:18, unless y'all know somewhere else? I can do 5:38 in the front and 5:43 in the rear.
« Last Edit: April 10, 2012, 11:36:47 AM by kbar »

Offline neale_rs

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Re: ring and pinion
« Reply #7 on: April 10, 2012, 12:12:22 PM »
5.38 and 5.43 will work fine, it's less than 1% difference.
'95 YJ, 33 x 12.5 mud tires, RE 4.5 ED lift, Atlas 4 speed, rear D44, ARBs front and rear, 4.56 gears, 8000# winch

Offline Jeffy

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Re: ring and pinion
« Reply #8 on: April 10, 2012, 12:24:36 PM »
With a Dana 44 and a Ford 9" you should be able to run 5.89's. 
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kbar

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Re: ring and pinion
« Reply #9 on: April 10, 2012, 12:50:29 PM »
With a Dana 44 and a Ford 9" you should be able to run 5.89's. 


I can't find a Dana 44 5:89 anywhere for sale. Plus isn't that a lil too low for a daily driver, I mean Idk and that's why I'm asking.

Offline FourbangerYJ

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Re: ring and pinion
« Reply #10 on: April 10, 2012, 02:14:29 PM »

I can't find a Dana 44 5:89 anywhere for sale. Plus isn't that a lil too low for a daily driver, I mean Idk and that's why I'm asking.

Is it a low pinion  (LP) or high pinion (HP) D44? The LP gears go to 5:89 and the HP stop and 5.38.

The 5.89 do sound real low but you have to keep in mind you went from a 27 inch tall tire to a 37 inch tall tire. The 5.89's might be a tad low but not by much. For street driving it will be fine. Not sure if I would want to wheel hard with that gear ratio since the pinion gear is pretty tiny at that size. So strength could be a issue.

The 5.38 and 5.43 (like Neale said) will be fine. It's close enough not to cause a problem.
Scott~

Using tools you have not used in a while is like shaking hands with old friends. :nod:

Offline sharpxmen

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Re: ring and pinion
« Reply #11 on: April 10, 2012, 03:18:05 PM »

I can't find a Dana 44 5:89 anywhere for sale. Plus isn't that a lil too low for a daily driver, I mean Idk and that's why I'm asking.
just going to use the previous calculation for stock like ratio
5.89/5.41 => 9% higher rpm at the same speed, so for example if you cruise at 3000rpm with stock tires and gearing at the same speed with the 5.89 gearing and 37'' tires you'd be at 3270rpm - ultimately it depends on what you're comfortable with but this is to give you an idea of what the change would be.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline Jeffy

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Re: ring and pinion
« Reply #12 on: April 10, 2012, 07:19:15 PM »
Is it a low pinion  (LP) or high pinion (HP) D44? The LP gears go to 5:89 and the HP stop and 5.38.

The 5.89 do sound real low but you have to keep in mind you went from a 27 inch tall tire to a 37 inch tall tire. The 5.89's might be a tad low but not by much. For street driving it will be fine. Not sure if I would want to wheel hard with that gear ratio since the pinion gear is pretty tiny at that size. So strength could be a issue.

The 5.38 and 5.43 (like Neale said) will be fine. It's close enough not to cause a problem.
IIRC, it was a Bronco D44 so it should be a LP.
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kbar

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Re: ring and pinion
« Reply #13 on: April 10, 2012, 07:28:34 PM »
From what I know of it's a HP. All the gears I find on rockauto.com for the year and 4x4 Dana 44 are all reverse cut.

Offline FourbangerYJ

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Re: ring and pinion
« Reply #14 on: April 10, 2012, 07:37:25 PM »
From what I know of it's a HP. All the gears I find on rockauto.com for the year and 4x4 Dana 44 are all reverse cut.
Look at the axle. Does the driveshaft connect above the axle tube line or below the axle tube line? Or post a PIC we can tell you.
Scott~

Using tools you have not used in a while is like shaking hands with old friends. :nod: