Help: 4.10 or 4.56

[PANCHORFO]

Need a litle input on this, just trying to figure out the best ring and pinion for my litle jeep, Is a CJ8 with a LBZ and using the nv4500 tranny and 37'' MT

The jeep is for Daily driver so the economy is important but also the power, that why i need recomendations

 

[Sledheadxp800r]

What's in it for gears now and what mods are done to the engine/fuel/air/tuning?

 

[PANCHORFO]

the jeep is unfinished, already has 3.73
The engine is stock with only 4” exhaust, intake,lift pump and Dsp5. I know a lots of silverados running 37” with 4.56 with great results but my tranny doesn´t have 6 speed. What do you think guys ?

 

[Harbin_22]

Run it and see if you like it or not would be my suggestion.

 

[whitetrash21]

You'd be surprised how well it'll pick up with 3.73's and 37's
I could roll the 38's off mine into 3rd with 3.73's. Stop and go mileage sucked (~10mpg), but avg'ed out on the freeway, I could do 16.

 

[DAVe3283]

I also recommend running it as is. You might like the 3.73s. Diesels are nothing like gassers with big tires. Put a tune on there, and you'll be surprised how well it does, without compromising your highway mileage.

Sent from my Galaxy Nexus using Tapatalk 2

 

[Rico]

Is this a wheeler also or just a daily driver? 456's may be a bit deep and 373's will run well on the street but 410's will be a happy medium to have the jeep perform decent offroad but not kill ya onroad.

 

[PANCHORFO]

The jeep is for daily driver, weekend warrior and for long trips.
Ok guys, I'll keep the 3.73 and see what happens.
Maybe in the future the 4.10s will be enough since the jeep is lighter than a silverado ( 2200 lbs less or something) so the power/weight ratio is gonna be insane ! :woott:

 

[diesel53]

does the tire effect how well it will pull? Toyo muds weigh about 93 pounds, not sure what trail grapps weigh or what you plan on running.

 

[PANCHORFO]

Bfg 37” km2, each 71 lbs

 

[1SIKDZL]

I am running 37" tires with the 5 speed Allison and 4:56 gears and love it. It does rev a bit high doing 80+ on the freeway, but at 70-75 I am sitting at 2300 rpms and I avg 18 around town and 20-21 on the freeway if I stay around 70 MPH. Plus, the 4:56 make it easy to spin those 37s off the line and make it really responsive for around town driving :thumbup:

 

[PANCHORFO]

I am running 37" tires with the 5 speed Allison and 4:56 gears and love it. It does rev a bit high doing 80+ on the freeway, but at 70-75 I am sitting at 2300 rpms and I avg 18 around town and 20-21 on the freeway if I stay around 70 MPH. Plus, the 4:56 make it easy to spin those 37s off the line and make it really responsive for around town driving :thumbup:

That´s what i needed , the owner of a 5 speed with 37”, 2300 rpm sounds a litle high to me ! Drove the truck with 37” and stock gearing ?

 

[1SIKDZL]

Yea, it did pretty good cruising at freeway speed...I think it was like 2000 rpms at like 70....but it wasn't as responsive as I wanted it to be for city driving. Your jeep is way lighter than my ccsb so it may not be as bad as mine was. If you do any bit of wheeling I would ditch the 3:73s at least and go with 4:10s at a minimum though.

 

[1SIKDZL]

37s are a lot of rubber to turn so it only makes sense to change the gearing from stock to see optimal performance.

 

[mackthehack]

I have 4.56's. Ran them with my 39's. Mileage sucked. Dropped tires size to 37's which is a little better, but not much. Around town 37's with 4.56's is nice and has alot of low end torq.

If you dd. I would go with 4.10's for good mpg's. I have been thinking about switching to 4.10's just for this reason.

You could get away with just 3.73's. I ran mine for about a year with my 39's until I limped my tranny getting onto the freeway once. And that was when I only had a diablo tuner. But since you're not running an alli. You don't have to worry about limping it.

 

[DAVe3283]

Yea, it did pretty good cruising at freeway speed...I think it was like 2000 rpms at like 70....but it wasn't as responsive as I wanted it to be for city driving. Your jeep is way lighter than my ccsb so it may not be as bad as mine was. If you do any bit of wheeling I would ditch the 3:73s at least and go with 4:10s at a minimum though.

4.10's may well be the ideal, but PANCHORFO has the advantage of already having 3.73's.

If it won't add to the cost to swap gears, I still recommend trying the 3.73's. If it will cost more to do the swap once the vehicle is assembled, then you might want to put in different gears now. However, I don't think the cost would be that different? If it is more, ask yourself if you'd pay $100 (or whatever) to be able to try 3.73's first, or if you'd rather go with something else without trying it.

I have stock 3.73 gears, and my truck weighs 8,200 lbs with me in it, but I only have 35" tires. It does 18-19 MPG on the freeway at 70 MPH, and turns 1850 RPM. With the stock turbo, it was plenty responsive in town. I put on a S371, and had to raise the shift points a little bit or it was pretty doggy in town. With a stock turbo and that light Jeep, you should be just fine.

Basically, unless it costs a lot more to change gears later, I would still recommend trying the 3.73's.

 

[1SIKDZL]

4.10's may well be the ideal, but PANCHORFO has the advantage of already having 3.73's.

If it won't add to the cost to swap gears, I still recommend trying the 3.73's. If it will cost more to do the swap once the vehicle is assembled, then you might want to put in different gears now. However, I don't think the cost would be that different? If it is more, ask yourself if you'd pay $100 (or whatever) to be able to try 3.73's first, or if you'd rather go with something else without trying it.

I have stock 3.73 gears, and my truck weighs 8,200 lbs with me in it, but I only have 35" tires. It does 18-19 MPG on the freeway at 70 MPH, and turns 1850 RPM. With the stock turbo, it was plenty responsive in town. I put on a S371, and had to raise the shift points a little bit or it was pretty doggy in town. With a stock turbo and that light Jeep, you should be just fine.

Basically, unless it costs a lot more to change gears later, I would still recommend trying the 3.73's.

Makes sense^

 

[Sledheadxp800r]

I bet That thing is going to rip with 3.73s. a max effort tune in a jeep will be sick no matter what size tires or gears you run.

 

[bigjohn]

3.73 if its a daily driver. If its for fun hill climbing and mud bogging then go with the 4.10s