4.88 or 4.56

9

94xjkyle

NAXJA Forum User

Location

north-cali

• Oct 18, 2005

• #1

im going to run 35" tires on a sometimes daily driver, with a D30 up front and either a ford 8.8 or yota 8" in the rear, what gears should i run? and dose anyone have an rpm range for apx. 65mph with both 4.56 and 4.88

 

xjj33p3r

NAXJA Member #1108

Location

garland, tx

• Oct 18, 2005

• #2

4.88

 

Rock Yacht

NAXJA Member #1242

NAXJA Member

Location

Cheyenne, WY

• Oct 18, 2005

• #3

4.56 ~ 2000RPM
4.88 ~ 2150RPM

4.56 ~ 34.73:1 CR (CR=Crawl Ratio)
4.88 ~ 37.17:1 CR
assumes AW4

What kind hills do you encounter on your drives? Lots of hills = 4.88, not so many = 4.56. Out here (Rocky Mts = BIG hills) I'd debate 4.88 or 5.13

Concider the strength issue to. the 56's will be a stronger R&P than the 88's

Then there's motor HO or non or stroker?

 

M

MENEZES

NAXJA Forum User

Location

San Jose, CA

• Oct 18, 2005

• #4

Rock Yacht brings up important issues you must think over. But just by going with your question, i would run 4.88s. I run 4.56s with 33s and wish i had gone 4.88s.

 

9

94xjkyle

NAXJA Forum User

Location

north-cali

• Oct 18, 2005

• #5

its a HO 4.0L and i live in the foot hills near placerville on highway 50, so yess there is some hills but nothing like the rockies

 

T

T&A-XJ

NAXJA Forum User

Location

Tarnation WA

• Oct 18, 2005

• #6

I would go 4.88s, more power, better mileage ect.

Only reason not to is the small pinion size which makes me leary but its proven to be strong enough in many jeeps... could be luck though

 

Matt98XJ

NAXJA Forum User

Location

Sanford Stadium, row 5.

• Oct 18, 2005

• #7

I run 4.56s. Wish I had 4.88s. I have 35 inch BFGs.

 

J

Jeffro600

NAXJA Forum User

Location

Cheyenne, Wy

• Oct 18, 2005

• #8

4.88's no contest! 4.56's are better for 31-33's in my book

 

W

willyb

NAXJA Forum User

Location

Superior

• Oct 18, 2005

• #9

I'd agree with Bob and the other's - 4.88's. But then the gears become another weak link [For the D30] because only two teeth are in contact, as opposed to three with 4.56's... I plan on going with 4.88's - but I'm not a throttle junkie either....

Decisions, Decisions

-Will

 

woody

NAXJA Forum User

NAXJA Memorial Lifetime Member

Location

NC Sandhills

• Oct 18, 2005

• #10

I've run 4.56 with both 31 and 33s... I wouldn't say no to 4.56 for 30" either, if not much highway use and hilly DD use. (4.0, auto or 5-speed)

4.88 is the cap for a HP30 so if you are working with one of those... :dunno:

 

9

94xjkyle

NAXJA Forum User

Location

north-cali

• Oct 18, 2005

• #11

HP D30 with auto tranny