4.56 or 4.88's for a CJ

[84jeepjohn]

OK this is from my pst on JU, I'm off to go drive the CJ so I'm just pasting it in... what do ya'll think?

NOW I am going to do my gears and lockers... go figure BIG QUESTION is 4.56 or 4.88.... here is the set up

258 (about to get MPI) T5 trany. dana 30 and amc 20 rear (with 1piece axles)
35" tires and currently 4.10's in the back (stock http://www.jeepsunlimited.com/forums/images/ubb/frown.gif up front....NO COMMENT LOL)

I am looking at t trutrac for the front and an OX for the rear, and I'm firm on them... I'm just up in the air on gears again. My buddy JUST put in 5.13's in his TJ but it has a 6 speed, and his advice is go 4.88.... well he has not even gotten up past 45MPH, cause that's what I'm worrying about.

I'm gonna have to DD this thing for at least another 2-3 years (then I get to get the tow vehicle (http://www.jeepsunlimited.com/forums/showthread.php?p=8420058#) http://www.jeepsunlimited.com/forums/images/ubb/wink.gif ) so I need it at least semi streetable LOL.and I do not want it screaming at highway speeds. NOW I do not expect to be pulling 80-85 (that's just bad ju-ju in mine) but I'd like to ba able to drive it above 55-60MPH

my OTHER wrench in the equasion is if I can EVER wear out my 35's I will get 37's NOW I KNOW what the usual is on 37's and stock running gear, BUT I do not wheel this thing AT ALL for now (but when we move there might be some decent wheeling. I'm chosing Air Force bases with a slant to where wheeling is around the base LOL)

So like I said I understand the short life of parts with the 37's but like I said it will only be wheeled light to moderatly.

Now my wife mentioned that "'you know we have the burb to go down to the city, and go places with the family" so yeah this will be more short hops by myself and just going to work in it. Man she's telling me to say screw it and get the 4.88's LOL http://www.jeepsunlimited.com/forums/images/smilies/love.gif http://www.jeepsunlimited.com/forums/images/smilies/rock.gif

I'm gonna take it out today and get it up to speed on the hi-way to see where I'm at (remember 6 moths in afghanistan, I've only gotten to pull this thing into the driveway yesterday LOL)

So what do ya'll think 4.56 or 4.88????

[miljeep]

I really wish I could help you with this, but this is waaaay above my current jeep skill level.

[korisu56]

If you're considering going 37's, I would imagine 4.88 or 5.13's would be your question. I'm not a CJ guy, but what I do know is that it is a pain in the ass enough not to do it more than once. Good luck with your answer hunting.

[trailsnail]

I'm going to have to go with Ryan on this one. But here is something that may help you make up your own mind.

http://www.4x4offroads.com/gear-ratio-chart.html

[korisu56]

According to that chart 37's should have 4.88 or 5.13. I would go with 4.88 probably and here's why.

You are currently on 35's so you'll get performance affect from the said gear set. However, if you went 4.56, I personally feel a bit sluggish on 35's, and when you made the bump up to 37's you'd really feel it. 4.88's would be on the low end of "Good Average Performance", which is right up your alley for a DD.

Just my .02, and everyone on here knows I don't know much. Let us know what you go with.

[trailsnail]

Definatly let us know, but also let us know how it rides.

[Truck]

I have 5.13 in my D60s on my Scrambler running 37s. I like them, but I also have a V8.

Truck

[HillBillE]

Just got back from Moab, my buddy's CJ is running 34'' tires, 4:10 gears, 258 w/MC2100 and "Nuttered" and the T176/D300.

(My buddy is 'mblackmarr' on JU, he may have responded to your post there)

He had a hard time holding 70+ on the flats, and was getting a lot of blowby at that speed. (Holding around 3K rpms.)

Being as you have a 5 speed, 4:56 would be perfect in my opinion, but if you're sure about going to 37'' tires, than I'd go with the 4:88's, and live with the shortness of speed until the bigger rubber went on.

[korisu56]

Hillbille! Where's the pics of Moab dude!

[theyeti1775]

PM Georgia for the CJ site we found the other night. Pretty helpful folks on there. Or just fire me a PM and I'll get it late tonight when I finally get home.

[HillBillE]

Hillbille! Where's the pics of Moab dude!

There is a link in the "midwest region' section, I'm still finding my way around the 'new' site:)

I'm uploading vids right now, I'll post up the links and story. HB

[84jeepjohn]

Just got back from Moab, my buddy's CJ is running 34'' tires, 4:10 gears, 258 w/MC2100 and "Nuttered" and the T176/D300.

(My buddy is 'mblackmarr' on JU, he may have responded to your post there)

He had a hard time holding 70+ on the flats, and was getting a lot of blowby at that speed. (Holding around 3K rpms.)

Being as you have a 5 speed, 4:56 would be perfect in my opinion, but if you're sure about going to 37'' tires, than I'd go with the 4:88's, and live with the shortness of speed until the bigger rubber went on.

my thing is I really do not see driving my Cj too much on the HWY. for anything "long" we will be in the burb :) the wife LOVES the jeep, but she will not drive too far in it HA HA

what size tires is Mblackmarr running? I saw his pics from Moab too and I'm curious cause his swampers look like 33's

[USMCHarleyJeepGuy]

I would go with the 4.88s on the gearing...BUT...I would really think about it before I bolted a set of 37s on your current axles. It might look good right up until you hear a very loud and audible POP!!! (and I don't think it would take you that long...)

[84jeepjohn]

I would go with the 4.88s on the gearing...BUT...I would really think about it before I bolted a set of 37s on your current axles. It might look good right up until you hear a very loud and audible POP!!! (and I don't think it would take you that long...)
I agree about the POP :)
BUT I have decided on the 4.88's, and I just ordered them about an hour ago. Now I'm just waiting on them to be delivered (and for UPS to drop off my rear OX today :) )

[USMCHarleyJeepGuy]

I agree about the POP :)
BUT I have decided on the 4.88's, and I just ordered them about an hour ago. Now I'm just waiting on them to be delivered (and for UPS to drop off my rear OX today :) )


Go easy on the skinny pedal and they'll last a lot longer if you can't replace them right away. :D