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Topic Review (Newest First)
04-30-2013 09:06 PM
JeepNz G
02-01-2013 01:34 PM
Blkfenderslookbetter
Quote:
Originally Posted by wimcle View Post
4.56 and 35s , will have you at 2600rpm at 70mph... I consider that to be just about right.
This is 5th gear in a '13 with 35" tires and 3.73's.

Why don't you just leave it in 5th?


I don't know that I could justify the expense of re-gearing. I don't tow anything more than a few miles, and certainly not very often. I do wish that I had a little more torque in 6th gear, but I just downshift a little more often. (Hey, thats why I spec'd a manual in the first place!)

I don't think the power loss is very substantial at all for 35's, and the only reason for me to consider would be for a gain in MPG.
Which:
a.) Is not going to be enough to offset the cost of regearing, in fact would probably reduce MPG
b.) And I can get the same pulling power in 5th with the stock setup
02-01-2013 11:32 AM
COStrider
Quote:
Originally Posted by WXman
Yes, for example: Your driveshafts are spin balanced to about 4,000 RPMs at the factory. Once you put those 4.88s in the differentials, suddenly that driveshaft is spinning WAY faster. Perhaps you get a vibration, or perhaps your CV joints go out, or perhaps it wears out the bearings in your T-case. Well, if they find out you did a gear swap, they have every right to deny coverage on everything else because now your entire drivetrain is out of factory spec. That's what I ran into.

As somebody else said...there may be some dealers that would be cool about it and help you out. Just know what the possibilities are before laying down $1,500 for gears.
Speak with your dealer and find out what they say. The dealer I go to says they lift their own Jeeps and say Jeeps are meant to be lifted and have bigger tires on them. They said they wouldn't deny warranty based on tires and lift. One tech even said look- there's my Jeep. It has 35's, at least a 3" lift and tons of add ons. The most modded Jeep in the lot (a different one) is one of the techs too!
02-01-2013 10:06 AM
Jap0505 I have a 13' as well but have the auto. It's sitting on 35's and looking at the gear charts i was thinking 4.56 too. Thoughts comparing the auto vs manual
01-02-2013 06:31 PM
bo9roadking
Quote:
Originally Posted by Savora View Post
I just regeared to 4.56 as well in a 2012 Sahara running 35s. Took a little time to decide between that and the 4.88 gears but was explained the 3.6 in the 12's already had more horsepower so the 4.56 was perfect. Because I'm running 35s I went ahead and upgraded with new axles & carrier and chose the Tera44 (great decision btw) and through in lockers while I was at it. I spend most weekends on the trails and the rest of the time on the highway putting an average of 2k miles a month on my girl. Enjoy your gears I believe you made the right decision
If my JK was not a daily driver with highway commuting, I might have gone with 4.88 gears, but I couldn't justify the higher rpms on the highway.

I'm happy with the 4.56 gears. With my 35" tires and 4.56 gears or even with 37" tires and 4.56 gears, my rpms are higher than they were with stock gearing and stock 32" tires, so I have room to grow from my 35's to 37's if I choose too. I don't know that I'll ever go larger than a 37" or 38" tire on a daily commuter because the tires get too expensive for me to justify driving on them for work every day. Since I have the 4:1 transfer case, offroad crawling is not an issue either with the 4.56 gears.
12-30-2012 10:33 PM
Savora I just regeared to 4.56 as well in a 2012 Sahara running 35s. Took a little time to decide between that and the 4.88 gears but was explained the 3.6 in the 12's already had more horsepower so the 4.56 was perfect. Because I'm running 35s I went ahead and upgraded with new axles & carrier and chose the Tera44 (great decision btw) and through in lockers while I was at it. I spend most weekends on the trails and the rest of the time on the highway putting an average of 2k miles a month on my girl. Enjoy your gears I believe you made the right decision
12-30-2012 09:23 PM
Seeuoffroad 2012 JKU. 35" tires. I went 4.88 also ARB lockers and Chromoly axels. The dealer did the work for me. The 4.88 just rock. I mean really rock! But I did get a vibration from the front drive shaft because of the higher RPM's.
So they put on a new drive shaft under warranty. So far they have been Honoring the warranty but i'm Sure that wont last forever and thats ok. i wanted a new jeep. i wanted it built the way i wanted and i was not going to wait 100 thousand miles for the warranty to expire. if it breaks I'll fix it thats part of running a off road rig. Its not my daily driving vehicle its my toy. I'm still tracking my gas mileage. Had a lot of in town running around today.
And was averaging 15.6 MPG.
12-30-2012 09:21 PM
WatchThis! I get that good and better and I drive then piss out of my 3.8
12-30-2012 09:13 PM
mflint1513 Yeah...good mix of highway and around town. Highway speeds around 70-80. Maybe I need to slow down a bit!
12-30-2012 09:01 PM
WatchThis!
Quote:
Originally Posted by mflint1513 View Post
14 mpg...hmmmm...
Haha realy
12-30-2012 08:55 PM
mflint1513 14 mpg...hmmmm...
12-28-2012 09:19 PM
bo9roadking
Quote:
Originally Posted by JeepHerz View Post

Post up when you've got your 4.56s installed. Would you mind checking your RPMs at 40? I could deal with my 3.21s (maybe) but when I hit 40 mph it upshifts to 4th- at about 1200 RPMs. Feels like a tank.I drive mostly city- and this is my main driving speed. Fiddled with the Procal and called my dealer. No love. (I tried searching "mod friendly dealer" but nothing came up.
Strange.)
I am surprised you are gearing up with 4.10s. I haven't heard they were bad- but there is always room for improvement. Enjoy!
Took the Jeep out for about a 30 mile ride this evening with the 4.56 gears in it. It moves a little quicker off the line than it did with the 4.10 gears and considering that the new axles are more than twice as heavy as the old stock axles, I'm glad to see the Jeep is more peppy even with the additional weight. Since I'm still breaking in the ring/pinion gears, I have to take it easy for a while, but I expect I'll be happy with the 4.56 gears. At 65 mph, I was still in the upper green ECO range of the tach. From a dead stop, the Jeep didn't feel like it was struggling to get moving.

To answer your question about driving at 40 mph with 4.56 gears, I was doing about 1600 rpm in the top gear with my 35" tires. It is hard to judge exactly since the tach isn't precise, but the needle was slightly above the white line that marks 1500 rpm. I hope that helps with your decision on choosing 4.56 or 4.88 gears.
12-26-2012 03:35 PM
JeepHerz So Santa brought 4.56s for Christmas. I am a little worried about highway RPMs since I am in 305/70/17s but I don't think 4.10s aren't enough. Dont want to handicap myself later. The Jeepy bank needs to recover so I can buy a rear locker. Meantime I'll still be researching.
12-23-2012 07:09 PM
bo9roadking
Quote:
Originally Posted by Lowerumble View Post
Well, paint me green!

What are you doing with you original axles? What kind of return do you get selling these sorta things. Running 35s with the 4.10s now and already thinking that spring may bring me 37s. Just trying to figure out my options...
I wasn't planning on hijacking this thread, but you asked. I'm going to sell my factory rubicon D44 axles with 4.10 gears and e-lockers that have about 14,000 miles on them. I'm not sure what I can get for them, so I have to do some checking. I'm going to wait until I get the new axles installed and everything is working good before I put them up for sale though.

The rubicon axles have Rock Krawler trackbar relocation brackets on both axles. The front trackbar bracket has a relocation hole for mounting the steering stabilizer above the tie rod for added clearance. The front axle is setup for the highsteer, so you can flip the drag link for better steering geometry on lifts that are 3" or higher. The only thing that the axles won't have on them is the brake rotors on the rear and the unit bearings on the front. I'm transferring those to the new axles.
12-23-2012 04:58 PM
damndirtydog
Quote:
Originally Posted by mflint1513 View Post
I'm wondering if that gear ratio is still gonna work for me if I ever upgrade to a Hemi.
I can't figure why they put a weak ass V6 in a Wrangler in the first place. I had a 4.7 V8 in my Ram and the wife has it in her commander. It's a great engine. A little gas thirsty, but the commander gets better mileage than my 09 Wrangler. I would have gladly paid 5-7K more for the satisfaction of having a V8 in place of all the other add on Junk that they easily charge 7 grand for. Maybe we wouldn't have to be swapping gears for every little mod we add. Never met a V6 that I liked.
12-23-2012 04:12 PM
Lowerumble [QUOTE=bo9roadking;3130934]Santa came and left these in my garage. I should have an answer for you late next week. If you look close at the upper left side of the Dana 60 and the left side of the Dana 44 pumpkins, you will see 4.56 stamped on them.
[QUOTE]

Well, paint me green!

What are you doing with you original axles? What kind of return do you get selling these sorta things. Running 35s with the 4.10s now and already thinking that spring may bring me 37s. Just trying to figure out my options...
12-23-2012 03:56 PM
bo9roadking
Quote:
Originally Posted by mflint1513 View Post
I'm wondering if that gear ratio is still gonna work for me if I ever upgrade to a Hemi.
The Dodge PowerWagon has a Hemi with 4.56 gears. I don't see why it wouldn't work.

If the 3.6 works, it should be even easier for the Hemi because it has more torque and horsepower. In fact, Chrysler is suppose to release a Hemi conversion for the 2012 JK auto anytime now and all it does is replace the torque converter in the existing transmission and adds the Hemi. One of the reasons that I opted for the Dana 60 in the rear was for the Hemi if I ever decided to do the Hemi conversion. The gearing should be fine.

With the 3.8 auto, the 4 speed transmission wasn't up to the task, so numerically higher gearing was still required or you had to swap out the transmission for a different one.
12-22-2012 04:08 PM
mflint1513 I'm wondering if that gear ratio is still gonna work for me if I ever upgrade to a Hemi.
12-21-2012 07:52 PM
bo9roadking
Quote:
Originally Posted by JeepHerz View Post

Post up when you've got your 4.56s installed. Would you mind checking your RPMs at 40? I could deal with my 3.21s (maybe) but when I hit 40 mph it upshifts to 4th- at about 1200 RPMs. Feels like a tank.I drive mostly city- and this is my main driving speed. Fiddled with the Procal and called my dealer. No love. (I tried searching "mod friendly dealer" but nothing came up.
Strange.)
I am surprised you are gearing up with 4.10s. I haven't heard they were bad- but there is always room for improvement. Enjoy!
Santa came and left these in my garage. I should have an answer for you late next week. If you look close at the upper left side of the Dana 60 and the left side of the Dana 44 pumpkins, you will see 4.56 stamped on them.
Attachment 189604
Attachment 189605
Attachment 189606
Attachment 189607
12-21-2012 06:39 PM
SilverSport
Quote:
Originally Posted by JKWrangler2012 View Post
i took your advice SS.. talked with the service folks yesterday during a visit.. they didn't seem to care one way or another about said mods.. he said.. if you blow the rear, that's on you.. if the pentastar takes a dump.. that's still on us.
See, no worries. The ball is in your hands, better start running with it. LOL

Quote:
Originally Posted by mflint1513 View Post
Makes me wonder something...how long does the powertrain (eng, trans, t case, axles) go for on the 2012? Is it 5 years, 35k?
5 YR/100K miles.
12-21-2012 03:03 PM
mflint1513 Yeah, gonna have to research.

Anyway, the new gears are great. I can stay in sixth gear and keep the cruise on without slowing down over a bump. Works great around town as well! Will post mpg numbers later.
12-21-2012 01:39 PM
JKWrangler2012 i believe it's 5 years.. 50k.. or longer. i forget
12-21-2012 12:50 PM
mflint1513
Quote:
Originally Posted by JKWrangler2012
i took your advice SS.. talked with the service folks yesterday during a visit.. they didn't seem to care one way or another about said mods.. he said.. if you blow the rear, that's on you.. if the pentastar takes a shit.. that's still on us.
Makes me wonder something...how long does the powertrain (eng, trans, t case, axles) go for on the 2012? Is it 5 years, 35k?
12-21-2012 12:32 PM
JKWrangler2012 i took your advice SS.. talked with the service folks yesterday during a visit.. they didn't seem to care one way or another about said mods.. he said.. if you blow the rear, that's on you.. if the pentastar takes a dump.. that's still on us.
12-21-2012 12:27 PM
SilverSport
Quote:
Originally Posted by JKWrangler2012 View Post
just me, 4WDH, and anyone whom notices the wire exiting the front diff... oh well.. patients, or the lackthereof, definately has a price
Jeeps with factory lockers have wires exiting the front diff so nothing unusual there.
12-21-2012 12:25 PM
JKWrangler2012 i'm going for it. i'm over stressing about it.. 3.21's aren't for me. going 4.10's + truetrac in the 44 and e-locker in the 30.. i don't necessarily need a locker, but the carrier needs replaced regardless and i want control over the steering interference. sticking w/ 32"s with no lift in sight.
12-20-2012 02:23 PM
sneck
Quote:
Originally Posted by JKWrangler2012 View Post
just me, 4WDH, and anyone whom notices the wire exiting the front diff... oh well.. patients, or the lackthereof, definately has a price
if you need lockers, then waiting 4 years for the warranty to end seems dumb. I don't get the idea of modding the jeep so much you will make it undriveable, but that you think regearing will the straw that breaks the camels back.

Besides, dealership techs arn't that smart. Unless you tell them its been modded, they probably wouldnt even notice an axle with a locker, because the jeep can come factory with it. Same thing for the gears, since jeeps dont all have the same gear ratio, that won't know it's been regeared unless they actually measure it.
12-20-2012 02:15 PM
JKWrangler2012
Quote:
Originally Posted by SilverSport View Post
^I always recommend getting a feel from your dealer on how they feel about mods, but as someone else mentioned, most likely no one but you would know that you re-geared.
just me, 4WDH, and anyone whom notices the wire exiting the front diff... oh well.. patients, or the lackthereof, definately has a price
12-20-2012 12:44 PM
bo9roadking
Quote:
Originally Posted by JeepHerz View Post

Post up when you've got your 4.56s installed. Would you mind checking your RPMs at 40? I could deal with my 3.21s (maybe) but when I hit 40 mph it upshifts to 4th- at about 1200 RPMs. Feels like a tank.I drive mostly city- and this is my main driving speed. Fiddled with the Procal and called my dealer. No love. (I tried searching "mod friendly dealer" but nothing came up.
Strange.)
I am surprised you are gearing up with 4.10s. I haven't heard they were bad- but there is always room for improvement. Enjoy!
My axles with the 4.56 gears are being delivered today and will be installed shortly after Christmas. I'm changing gears because I'm going to a 37" tire when my 35" tires are worn out. I'm also changing from my Rugged Ridge wheels to ATX Slab beadlocks that weigh more. With the additional weight of the wheels and larger tires, plus heavier duty axles, I changed my gears to 4.56 to help move the weight. I could live with the 4.10 gearing with 35" tires if nothing else changed. I'll let you know how it works out.

The added bonus to the 4.56 gearing is that it works for the 35" tire if I decide not to stick with 37" tires. If I start getting a little crazier, I could do a 38" or 39" tire and the rpms with 4.56 gearing won't be any different than what it was with my 35" tires and 4.10 gears.
12-20-2012 12:37 PM
JeepHerz
Quote:
Originally Posted by bo9roadking View Post
For a 3.6 Pentastar with the 5 speed auto, 5.13 gears are too much unless you never drive on the highway or you are running 40" tires.

On my 2012 JKUR auto, I have 4.10 gears. I'm getting new axles with 4.56 gears installed next week. The 2012 JKUR auto came stock with 3.73 gears unless you upgraded to 4.10 gears from the factory.

Running a 4.56 gear and 37" tires puts the rpms about 130 rpm higher than where they were with 3.73 gears and stock 32" tires. If you had the optional 4.10 gears with the stock 32" tires, the rpms are about 95 rpm higher than running 4.56 gears with 37" tires.

For a 35" tire, 4.56 gears put the rpms about 160 higher than stock 4.10 gears and 450 rpms higher than if the JK came with the 3.73 gears.

IMO, 4.10 and 4.56 gears are a good choice for 35" tires. 4.56 gears work for 35" and 37" tires. If you never decide to go larger than a 37" tire or if you might downsize back to a 35" tire, there is no need to go for more than 4.56 gears, especially if you have a Rubicon 4:1 transfer case for offroading.

Regarding the warranty, my front D44 has been in the shop twice for a leaky oil seal that was covered under warranty. My JK has also been in the shop once for the CEL misfire on cylinder 6, but I'm not going to be held hostage by Chrysler if I want to mod my Jeep. After next week, nothing under my Jeep will be factory anyway except the rear rotors and calipers, transfer case, transmission, and engine.

Post up when you've got your 4.56s installed. Would you mind checking your RPMs at 40? I could deal with my 3.21s (maybe) but when I hit 40 mph it upshifts to 4th- at about 1200 RPMs. Feels like a tank.I drive mostly city- and this is my main driving speed. Fiddled with the Procal and called my dealer. No love. (I tried searching "mod friendly dealer" but nothing came up.
Strange.)
I am surprised you are gearing up with 4.10s. I haven't heard they were bad- but there is always room for improvement. Enjoy!
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