31.5in Stock Sport Tires with 5.88 Gears 6MT

[Deleted member 39643]

Hi all, doing some research to get the most usability out of the stock 6MT gearing. I will probably regear before getting any new tires so this comparison is using the stock wheels 245/70R17 which are about 31.5 inches. Stock is 3.73 gears. I don't want to do any hard core wheeling, just driving fire trails. I got a dirt bike for anything extreme. I eventually may add 35s, which will lower everything back down again if this setup is to crazy.

Curious about a couple things:

1. does this setup make any sense?
(I really just want power in all gears, and feel like that is currently limited by driving at under 2k rpm all the time.)
2. would I be able to start in 2nd and use first for crawl?
(This would make 2nd way more usable, don't need to drive around at 60+ in 2nd gear)
3. 60 mph shows as 2700, 70 at 3100. Any trouble running the pennty that high on the freeway?
(don't care about mpg, not planning on going over 75)

The stats on the left are for stock setup, on the right is theoretical 5.88 gearing with stock wheels

stock crawl vs theoretical, the lower the better?

gear calculator http://www.grimmjeeper.com/gears.html

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[AustinL911]

5.88s or 4.88s?

I eventually plan on 35s and 4.88s when my 6MT JTR arrives. That's a size steeper than most typically go (4.56). I wanted a little extra grunt though. 5.88 would be a bit much, IMO. Do they even make those for the D44?

Also, the 2nd stage oil pump kicks in at 3k rpm. Not sure I'd want to cruise around like that.

 

[Deleted member 39643]

5.88s or 4.88s?

I'd probably go as high as I could, 4.88 still seems to low, 3rd still gear goes close to 100 mph with 4.88

Also, the 2nd stage oil pump kicks in at 3k rpm. Not sure I'd want to cruise around like that.

Good to know on the 2nd stage pump, but I don't know if I can cruise on the freeway 2-3k, Under 2k no power, over 3k oil pump. Maybe just plan on selling once warranty goes out.

Here are the 4.88 numbers for comparison,

 

[Deleted member 39643]

Might be right that there are no 5.88s, this site is advertising 5.38s for the JT Dana 44, that might be as high as I can go.
https://www.sierragear.com/ring-and-pinion-gear-sets/ring-and-pinion-gear-sets-dana/

 

[hjdca]

I have 5:13s with 37" tires and the 6 speed JTR. This is actually perfect. Lots of torque multiplication and power through the 1/4 mile. The truck really moves.. You can easily start in 2nd gear. Granny gear is awesome and 6th gear pulls small hills on the fwy now. For gearing, You do not want to go too low or too high, just right is the ticket. Here is my view on the optimal situation.

1. Stock Gladiator Rubicon 6 speed with 33" tires - 4:56 gears
2. Gladiator 6 speed with 35" tires - 4:88 gears
3. Gladiator 6 speed with 37" tires - 5:13 gears.

I believe if you go higher than that, then, you may be leaving some gas mileage behind without much additional torque benefit.

 

[AustinL911]

I have 5:13s with 37" tires and the 6 speed JTR. This is actually perfect. Lots of torque multiplication and power through the 1/4 mile. The truck really moves.. You can easily start in 2nd gear. Granny gear is awesome and 6th gear pulls small hills on the fwy now. For gearing, You do not want to go too low or too high, just right is the ticket. Here is my view on the optimal situation.

1. Stock Gladiator Rubicon 6 speed with 33" tires - 4:56 gears
2. Gladiator 6 speed with 35" tires - 4:88 gears
3. Gladiator 6 speed with 37" tires - 5:13 gears.

I believe if you go higher than that, then, you may be leaving some gas mileage behind without much additional torque benefit.

+1 to everything this fella said.

 

[hjdca]

I have 5:13s with 37" tires and the 6 speed JTR. This is actually perfect. Lots of torque multiplication and power through the 1/4 mile. The truck really moves.. You can easily start in 2nd gear. Granny gear is awesome and 6th gear pulls small hills on the fwy now. For gearing, You do not want to go too low or too high, just right is the ticket. Here is my view on the optimal situation.

1. Stock Gladiator Rubicon 6 speed with 33" tires - 4:56 gears
2. Gladiator 6 speed with 35" tires - 4:88 gears
3. Gladiator 6 speed with 37" tires - 5:13 gears.

I believe if you go higher than that, then, you may be leaving some gas mileage behind without much additional torque benefit.

The other thing to remember is that your computer controlled oil pressure is doubled at 3K rpm, so, you do not want to be over 3K rpm and double the oil pressure every time you get up to fwy cruising speed.

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