4.88s

[sledheadak]

4.88s too low for 33" tires with a 5th gear od?i know it will be quick but kindo of wondering about the revs with them

 

[parts4now]

Randy's Ring & Pinion has an easy to use gearing/tire size/rpm calculator on their site. Just plug in the numbers and you will know.

 

[fmstruck]

Assuming a .8 overdrive, your numbers run through a calculator show: 2385rpm @ 60 mph. If you leave it in 4th: 2981rpm @ 60 mph.

 

[Blue85]

I wouldn't swap in 4.88s if I would run 33's. But if they were already in there it would be OK as long freeways are rare. Which transmission do you have with 0.8? That's like 3k on the freeway - like a Jeep!

 

[sweetk30]

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

2422 rpm @ 65 mph with 4.88/nv4500/33" tires.

 

[rjfguitar]

Looks like good numbers to me. I'd do 4.88's with 33's in a heartbeat.

 

[6.2Blazer]

It's probably not the optimum gear ratio for gas mileage while cruising down the freeway, but it would work just fine. A stock Chevy 2500HD with 4.10's (which a majority were with the 6.0L) spins right around that same rpm.

 

[Stomis]

Yes do it.

 

[imiceman44]

4.88s too low for 33" tires with a 5th gear od?i know it will be quick but kindo of wondering about the revs with them

Well, I wouldn't do it in a K5, but I might with a crew cab.
SO what's this in?

 

[sledheadak]

lol its my xj.i might be getting a set of rubi axles that have 4.88 gears in them.it my little rig.it has the ax15 5 speed.

 

[sweetk30]

2551 rpm at 65 then if ax-15.

 

[imiceman44]

lol its my xj.i might be getting a set of rubi axles that have 4.88 gears in them.it my little rig.it has the ax15 5 speed.

4.0 engine?
if so, that is not too bad.
If it was a 5.7 GM on a K5 it would be too much gear but the XJ has a smaller engine, I think it needs at least 4.56 to be comfortable with the tires size.

 

[sledheadak]

4.0 it should be pretty quick

 

[1BEATK5]

i put 4.88s in my brothers xj w/33s (aw4) and its about right. 4.0s dont have any power under 2200rpm anyways. they need some rpm to maintain freeway speeds, up hills and such.

 

[rjfguitar]

It's much easier to find yourself saying, "Should have geared lower, OOPS" than "oh crap, it's way too low now." Gas engines like to spin some revs, especially pushing big tires around.

 

[fmstruck]

All this makes me chuckle to think I used to DD my '79 Malibu with 4.56s on 28" tires with no overdrive. 3370rpm @ 60.

 

[Blue85]

lol its my xj.i might be getting a set of rubi axles that have 4.88 gears in them.it my little rig.it has the ax15 5 speed.

Ah, I knew this sounded like a Jeep question. Those rigs get 4.88s with 35s as the standard build. I think it would be OK with 33s in that application. I mean, 4.56 would be better, but not worth the swap.

 

[sledheadak]

esp not for the price im gettin them for lol with the air lockers etc already in them.