Jeep Wrangler Forum banner

SCREAMING 4.56 Owners

9K views 41 replies 31 participants last post by  lumpy1977 
#1 ·
Re-geared to 4.56s? In a 3.6 Pentastar? Please post your highway RPM/performance results here. Have your ears burst at 70 MPH? Has your engine blown up in smoke? Do Honda race boys try and go all Fast N' Furious on you? Do you wish you'd gone 4.10s because the extra performance is just too much?
If you've noticed a bit of sarcasm- I would like to put the "screaming" on the highway RPM issue to bed. :deadhorse:(Or not). It seems that every gear thread someone mentions it- yet no one to my knowledge has ever posted to say they regret 4.56s for this reason. "Some guy" somewhere says 4.56s are too much on the highway. Please- if you're that girl/guy AND YOU HAVE 4.56s- come forward. I promise no harm will come to you or your Jeep. If I am living in a dream world where 4.56s on 35s are ideal- burst my bubble. Gently.
Seriously- if you have 4.56s, even if you DO think they're too much- post it. Let 'er rip. Like them? Post it. Asking for performance results only- not the wheres or the why or the scientific method behind force vs. rotational mass. Just the facts ma'am.
 
#2 ·
I have not heard that at all. I'm actually planning on going with the 4.56 gears, they are on order. I'm hearing when you go 4.88 - 5.13 is when the over the 3000 RPM's and start to hear the engine revving. I'm curious to hear all the 4.56s chime in.
 
#3 ·
I ran 4.56 on 33s for a long time without issue, didnt seem over reved. Once i was on 315 duratracs it was perfect. Zero regret. I have a YouTube video of my jeep on 33s showing the rpm at 70mph. I can link it if it's relevant and helpful.

Sent from my Nexus 6P using Tapatalk
 
#7 ·
Many threads on this, so I'm finally posting my reason for going with 4:56s. It's a Sport S with 3:21s, take-off Rubicon shocks and 32" tires (Firestone Destination AT - 275/70/17.) If I do anything to it I may install a leveling kit.

My Wrangler is a mall crawler. I'm not going to wheel it. Living in New England gives me all kinds of weather - top down/doors off to major snow storms. I have all types of driving experiences for which to have fun.

All my previous vehicles were performance cars. I'm going to re-gear to 4.56 for (IMO) the best bang for the buck. I don't drive over 60mph, except to pass. I get it, it's a Jeep, but I want more "get up and go". I've been thinking about this for a year, and I think for my needs, I'll be happy.

The Quadratec G2 package seems reasonable, and I know a reputable shop in the area. For over $1,700 (parts/labor) including a ProCal, this sounds like a reasonable price.
 
#8 ·
I have a 13 JKU with 4.56's, 35's (33.5" tall in reality) and auto, at 70mph i'm at 2700rpm, 3100rpm or so by 80mph, and still don't feel the engine screaming at that point, i can make it scream on purpose at 6500-6600rpm putting the pedal to the metal for the 1-2 and 2-3 shifts though :)
 
#9 ·
I just re-geared to 4.56's and had e-lockers installed. My tires are 33" ST-Maxx's, so nothing crazy. The motor definitely spins up quicker, but nothing horrendous. I absolutely use 6th gear now too. With the 3.21's, I had a hard time using 6th on a level road wide open. I dont regret the re-gear at all, especially with the lockers. While 4.56's may be a bit much for 33's, if I ever decide to jump to 35's Im already set up.
 
#14 ·
To jump on the thread, I am in the 4.56vs4.88 debate. Those that have the 4.56, do you have added weight (bumpers/winch) and have you towed with them?
 
#16 ·
To jump on the thread, I am in the 4.56vs4.88 debate. Those that have the 4.56, do you have added weight (bumpers/winch) and have you towed with them?
JK or JKU? I have about every skid known to man- plus SST bumpers front and rear, fenders and sliders. JK auto. 4.56s are great. Because I rock crawl and I like fast(ish) I almost, kind of, maybe, :D wish I'd done 4.88s- but no regrets whatsoever. For a DD- no way. I'd have to carry a (second) gas tank with me. So for you I guess the question is how important is the tow? I can't imagine there would be that much of a difference but either way you'll be good. 4.56s really are about perfect for a JK IMO- 4.88s would just give you a little bit of extra oomph.
 
#17 ·
4.56 with 35= 2650, 2700ish at at 75mph. Not screaming but not "ideal" cruising rpm either. Can't have it all. I'm not complaining, just sayin. Its world's better than the 3.21s.
For those on the fence with 4.56 vs 4.88...drive your jeep at a constant 2650rpm for a few miles. Then do the same at 2850. If the 2850 don't matter to you then you'll be happy with 4.88. If it's annoying stay with 4.56.
 
#18 ·
No screaming here. It drives like stock pretty much but I went straight to new gears once I changed tires. Around 70mph I'm near 2800 when cruising. Gas mileage can go from 15-17mpg combined depending on my driving and where I'm driving.
 
#19 ·
Ive got 5.13's and 35s on now on my 2011 and it does scream on the highway with 35's with 37s not as bad.. Im not exactly sure but think its a little over 3000 rpm at 70 on current 35s, but my speedometer is not calibrated for the tires so Im not sure exactly how fast I'm going.. What it does do is makes first gear like a tank, normally don't use 1st gear on streets, but actually use 6th gear often which never used on 3.21's. 4.56's are probably about right for most folks who wanna use it regularly on highway and go fast yet still have power at slow speeds.
 
#21 ·
I have 4.56 on a 2015 JK. w/35 that measure 33.5. The engine doesn't scream but the rpm are a little high for daily driving. I feel like for my needs I should of went to 4.10. I feel like I cant go over 60mph rpms are around 2500 without my mpg going down a lot. I feel like 60 is too slow on the hwy.65-70 is nice cruising speed. The original 3.21 were really slow, I used to be only at 1600-1700 at 60mph before and felt like I had trouble keeping speed.
 
#23 ·
Just FYI- someone chimed in on a thread that they had a JKUR with 4.10s and a JKU re-geared to 4.56s. If there was a difference in MPG they never noticed. I know someone that has had two JKs- same there. Small enough difference to not be noticed. The only way to have good highway gas mileage...is stock tires on 3.21s.
Which we all know sucks. :)
 
#24 ·
I run 5.13 on 37s, DD 105 miles round trip every day and love it. Don’t really care about gas
Mileage but only lost a little over 1mpg from stock 32s and 3.73s. Once you get used to 3100rpm at 80 it’s no big deal. Tire noise drowns out any engine noise. Life is too short to worry about stupid shit like that.


Sent from my iPhone using Tapatalk
 
#26 ·
My 14 has heavy bumpers, winch, lifted and 315's. 3.73 now and thinking of 4.56. Lots of freeway driving here in So Cal at 75 MPH. 4.88's are out. It really goes well on the freeway at 80 now as many do. If it's a great 0-60 gain going up hill or holding 65 mph in 5th then it might be worth it. I do have a 4th gear I can use. I really don't wheel much and no rock crawling. Any MPG gain will never pay for the gears. If I had 4.10's I would never change them.
 
  • Like
Reactions: SBAmadeo
#28 ·
I have a 2013 2 dr automatic, for 4 years I ran 315 duratracs on 3.21. Last August I moved up to 4.88's and never looked back. 4.56 would have been fine too but I wanted (and now have) 37's. Yes I built it right so lets not go there. The 37's with 4.88 for me at my elevation in Wisconsin is great. Wheeled it a few times and can feel the difference. Its not terrible on the hiway, definitely driveable BUT if you are a gas watcher then turn away. It is fine going slow and it will drink gas at hiway speed. I don't care about gas mileage so not an issue. Otherwise I kick myself for suffering with 3.21 for soooo long.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top