• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Gearing.....4.56 va 4.88's

R

rebeltruce

NAXJA Forum User
Location
Virginia
Recently lifted, and running 33's.....I've noticed a big difference, and I'm not liking it.

I am going to re-gear..question is (and I've searched)..... D30/8.25

I understand 4.56 will get me close to stock, but I'm thinking the Nitro 4.88's are the way to go.

Jeep really only see's the highway...any reason not to go 4.88's and how will this effect the performance versus 4.56's?
 
go 4.88's. EVERYBODY I know that re-geared for 33's later went to 35's.

Im running 5.13's with 35's at the moment, and it is not bad at all.
 
I am running 4.88 and 31's.... I can still cruise up to 70 MPH... It is a Jeep and lifted at that... No need to run 80 MPH

Sure is fun around town messing with the ricers at stop lights
 
If you drive on anything higher than an ant hill, get 4.88s. On the freeway, your rpm's will be approximately 200 revs higher with 4.88s than 4.56s.
 
Thanks Fella's for the replys.....y'all have confirmed exactly what I was thinking.

4.88's it is....plan on arranging things with Pro Trucks in Fredericksburg Va, this weekend....
 
nice! re gearing is way worth it. Consider a locker NOW because it is the same cost of a gear install.

If its mostly a street jeep, consider an electric locker in the rear. It really doesn't get much worse then a built jeep with open axles. Save yourself some embarrassment down the line LOL!
 
brandon350 said:
You have the same setup I do. 8.25/HP30. I went with 4.88s on 33s and so far I don't regret it in the least! I've only had it back for one weekend now but I LOVE it!

Pics @ http://www.facebook.com/album.php?aid=2094379&id=1156566686&l=7a66af92d7
Click to expand...

hey I was bored so I looked through your pictures! Loving the Firestones with the white side out! When I need new tires on my Wagoneer I think I am going with the 31" Firestone M/T's.

Oh and here is a picture of my jeep on the same bridge (I think):
25835_1440030400566_1227211950_32148759_842456_n.jpg
 
i went from 33s to 35s on my 4.88s.
i only wish the dana 30 could fit 5.29s
noticable loss of power with the 35s and 4.88s.
the 4.88s turned the 33s like stock.
all in all i love it on 35s and 4.88s.
i feel like it would be a bad idea to not go to 4.88s, you will regret 4.56s if you have a choice.

if youre installing them yourself do 4.88s

now if you find a set of geared 4.56 axles with lockers and the rear is a 8.8 or a 44 and the price is like 800 or under run 4.56s.

if youre paying a shop, do it once, and do the 4.88s.

i ran 31s on 3.55s and 4.88s
ran 33s on 3.55s and 4.88s
ran 35s on 4.88s

it was alwasy better with 4.88s.

never once did i think i was revving too high on the freeway , even with the 31s.
65- 70mph and im happy
 
its not as much about RPM as it is about throttle. if youre running lower RPM but need more throttle to keep a steady speed, bogging down a little, then youe mileage will be worse than if you were at higher RPM and less throttle input.
 
The XJ I owned prior to the one I Have now has 4.88's with 33's.

Even with my 33" spare mounted to the roof I got a steady 18 MPG on the hwy cruising 70-75 MPH between Ocala, FL and Tellico going to the crawl in '06. This was also carrying 5 people and all the associated camping gear for 5 people.

RIght now I have 4.10's and 30's (soon to be 31's I hope) but if I ever go up I will run 4.88's for sure again. And if I go bigger than 33's it's time for bigger axles and deeper gears.

The 4.0L will cruise at 3000 RPM (probably even higher) all day and not miss a beat. Believe it or not it seems to smooth out when it gets in that range (provided it's an 'in shape' motor). Gear it down and don't look back.
 
I guess ill be the first to say 4:56s. I’m on 33s and just regarded from the stock 3:55s and I love it. If you’re concerned about MPGs 4:56s will get better MPG then 4.88s on 33s. Well I cant say that as a fact because I have never ran 4.88s but now on 4:56s and 33s I can use overdrive without constantly down shifting, the rpms are higher cruising at 65mph then a stock jeep would be so going to 4.88s would be even higher rpm which will decrees mileage IMO.
 
I'm running 4.56s on 285/75/16s and it'll shift into overdrive at 40mph and doesn't downshift on hills. Very happy with this setup...I'm at 2200 rpms at 60mph. Maybe if you step up to 35s it wouldn't be that great...

I don't think you can go wrong either way
 
I am currently running 32 inch tires on my comanche with AW4 auto tranny, I was planning on running 4.56's but after reading this I might step up to 4.88's. I like running 32's and will probably never go any larger but if I do I would not go higher than 33's.
 
i started out with 3.07 gears and a manual. swapped 3.55 geared axles in (off an automatic) and i run 35in bfg AT and it feels stock. definately dont have a problem passing cars on the highway. shit lol ive taken my jeeps spedomiter all the way back to 0. and i still have no problem crawling with my foot of the gas. when i get 37s im going with 3.56 gears, unless i decide to go with bigger tires.........
 
Going to get some pricing on 4.88's today, found a local shop so no need to make the drive to Fredricksburg.

I'll post the estimate at some point today just to get an idea if it's fair....been looking into Electronic Lockers and some Posi systems. I don't really see the need for full Lockers, but some sort of Posi for the rear end is likely.

The system I'm looking at is here (Quadratec):

http://www.quadratec.com/products/p...Go!&h=t&cn=PowerTrax+No-Slip+Traction+Systems
 
If you see mostly highway why go so deep?


I'm on 33s I'm running 4.88 and ran 4.10 before. While the 4.10 lacked power on the street and in the hills I was getting around 19mpg hwy and did just fine on the trails in low range. I've been under 15mpg since I went 4.88. If I didn't offroad and didn't live in the mountains I'd go for the lower number. Living in hills 4.10 would be unbearable, but 4.56 would be ok.

The key arguement I'm presenting is, is it worth that much less mpg on the highway if all you do is drive it on the highway? Of course if you EVER think you MIGHT go to 35s, there is no question, go 4.88.
 
1. Are you going to hard off a lot yes/no
2. Do you tow or run very heavy a lot: yes/no
3. Is it a stick: yes/no
4. Did you want more power when at stock tires and stock gears. yes/no
5. Are you willing to give up some MPG for more power. yes/no
I say if you got 4 or more yes's then go deeper then 488
With 3 yes 488.
2 or less then 456
Calling someone else gears is all but impossible. We just don't know what you like over the web. But maybe this can help you make the call
Maybe someone could refine this list and make it aply to any 2 gears. LOts of dudes get stuck when picking between 2 close gear sets. then make it a sticky.
 
Last edited:
You must log in or register to reply here.

Similar threads

L
Realistic MPG 4.0/AW4 33's with 4.56 gears
Replies
9
Views
150
XJlimitedx99
X
V
High temp woes
2
Replies
21
Views
399
Vitzaa
V
I
Bought Son 2000 XJ, Need Help with RC Lift
2 3
Replies
45
Views
6K
Tim_MN
Tim_MN
S
96 XJ rear axle ratio
Replies
3
Views
1K
RCP Phx
R
K
How does backspacing affect handling? 3.75 vs 4.5 backspacing for 31 x 10's?
Replies
11
Views
4K
XJEEPER
XJEEPER
Back
Top