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-   -   Why should I NOT go with 4.56s? (http://www.wranglerforum.com/f274/why-should-i-not-go-with-4-56s-205404.html)

mflint1513 12-14-2012 11:57 AM

I'm finally going to regear. 2012 JKU SportS, manual, 35s, currently with 3.73s. I'm havin issues with constantly having to downshift whenever I'm at highway speeds and towing is a painful experience. As I read and research, 4.56 gears bring me back to a stock driveline with a 4.1:1 final drive. Apparently this is optimal. Most guys say go 4.88 but they say that as thy don't have a lot of highway driving. So, final thoughts? any reason I should NOT go 4.56?highway driving to do.

panthermark 12-14-2012 01:35 PM

I'd say that a lot of the 4.56 hate was based on the old engine/tranny combo where it made little sense to go 4.56's. If you were going to make the swap pre 2012, go 4.88 or 5.13.

But with the new engine/tranny, I would think 4.56's are OK if you do a lot of highway driving. I'm sure others with far more knowledge can chime in.

wimcle 12-14-2012 01:40 PM

4.56 and 35s , will have you at 2600rpm at 70mph... I consider that to be just about right.

WXman 12-14-2012 01:50 PM

Why not? Because your 100,000 mile powertrain warranty on the axles is a valuable thing and you'll throw it out the window.

I regeared my '11 and I'll never do it again. Ever. Opened up cans of worms that I didn't want to deal with. What a PITA.

Six 12-14-2012 02:02 PM

Quote:

Originally Posted by WXman (Post 3104053)
Why not? Because your 100,000 mile powertrain warranty on the axles is a valuable thing and you'll throw it out the window.

I regeared my '11 and I'll never do it again. Ever. Opened up cans of worms that I didn't want to deal with. What a PITA.

Like?

WXman 12-14-2012 02:33 PM

Quote:

Originally Posted by Six (Post 3104075)

Like?

Like denial by two dealers plus Chrysler to honor warranty on other drivetrain components such as driveshaft joints when they went bad. Ended up without my Jeep and fighting with Chrysler over it for a while. Really big headache. $900 headache. Fool with your gears and kiss your drivetrain warranty goodbye because you put everything connected to them out of factory specs. To me it's not worth it.

snochick 12-14-2012 02:39 PM

Quote:

Originally Posted by WXman

Like denial by two dealers plus Chrysler to honor warranty on other drivetrain components such as driveshaft joints when they went bad. Ended up without my Jeep and fighting with Chrysler over it for a while. Really big headache. $900 headache. Fool with your gears and kiss your drivetrain warranty goodbye because you put everything connected to them out of factory specs. To me it's not worth it.

Yea. That's why some things will be done to mine after its paid off and warranty is expired. Right now dealer even has to cover my lift bc they did it. I'm cool with that.

XTRyan 12-14-2012 03:11 PM

Quote:

Originally Posted by mflint1513 (Post 3103664)
I'm finally going to regear. 2012 JKU SportS, manual, 35s, currently with 3.73s. I'm havin issues with constantly having to downshift whenever I'm at highway speeds and towing is a painful experience. As I read and research, 4.56 gears bring me back to a stock driveline with a 4.1:1 final drive. Apparently this is optimal. Most guys say go 4.88 but they say that as thy don't have a lot of highway driving. So, final thoughts? any reason I should NOT go 4.56?highway driving to do.

mflint1513,

I think that you got some really good advice above from panthermark. He's right about 4.56's being more appropriate on the new 12+ Pentastar and NSG370 trans, especially if you're worried about highway driving. You've got 35's on there, so it's pretty justified and I think it will still feel plenty powerful!

We have a few different options that you might want to take a look at. Check out all of our Jeep Gears for JK Wranglers! We have free shipping over $75 and also offer a forums discount code, so PM me if you need it!

Good luck!

Phil

MrAugie 12-14-2012 03:22 PM

Quote:

Originally Posted by WXman (Post 3104153)
Like denial by two dealers plus Chrysler to honor warranty on other drivetrain components such as driveshaft joints when they went bad. Ended up without my Jeep and fighting with Chrysler over it for a while. Really big headache. $900 headache. Fool with your gears and kiss your drivetrain warranty goodbye because you put everything connected to them out of factory specs. To me it's not worth it.

That's some good info. But if you bought the extended warranty and don't want it anymore, can't you sell it back? I know I got cash back when I got rid of a Honda that I had purchased an extended warranty for, like 1,600 bucks. That would pay for gears.

Warranties are a PITA.

mflint1513 12-14-2012 04:00 PM

Good info overall and thanks for the input. I'm not sure about the warranty issue. I've found two dealers that say they'll cover everything but the gears themselves (in SoCal), two that won't touch it (NY and OH) and one that didnt even know you could change gears nor fathom why you'd want to (AL)!
It just depends on the dealerships. Plus the swap is covered by the place doing the work and parts are covered by the manufacturer so I'm not worried there.
Thanks again for all the input and Phil, I'll PM you on some stuff!

Six 12-14-2012 04:17 PM

Quote:

Originally Posted by mflint1513 (Post 3104384)
Good info overall and thanks for the input. I'm not sure about the warranty issue. I've found two dealers that say they'll cover everything but the gears themselves (in SoCal), two that won't touch it (NY and OH) and one that didnt even know you could change gears nor fathom why you'd want to (AL)!
It just depends on the dealerships. Plus the swap is covered by the place doing the work and parts are covered by the manufacturer so I'm not worried there.
Thanks again for all the input and Phil, I'll PM you on some stuff!

The problem is the additional parts that the dealer can blame on regearing when they fail. They could essentially deny warrant on the transmission, engine, and other points saying that the extra stress caused the failure.

WXman 12-14-2012 07:42 PM

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.

JKWrangler2012 12-14-2012 08:09 PM

Quote:

Originally Posted by WXman (Post 3105043)
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.


wow. lots to think about here. been wanting to change gears and add eaton provisions front and rear. if i were to add 4.10's and keep the factory size 255 75 17's.. would my warranty still be void? near ready to pull this 3.5k upgrade trigger and now a complete reality check.

panthermark 12-14-2012 08:09 PM

Quote:

Originally Posted by mflint1513 (Post 3104384)
Good info overall and thanks for the input. I'm not sure about the warranty issue. I've found two dealers that say they'll cover everything but the gears themselves (in SoCal), two that won't touch it (NY and OH) and one that didnt even know you could change gears nor fathom why you'd want to (AL)!
It just depends on the dealerships. Plus the swap is covered by the place doing the work and parts are covered by the manufacturer so I'm not worried there.
Thanks again for all the input and Phil, I'll PM you on some stuff!

:eek:
:facepalm:
:rofl::rofl::rofl:

mflint1513 12-14-2012 08:12 PM

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.

I understand the issues about warranty. However, if you put bigger tires on it, you cause similar issues. More rotational inertia and overall weight potentially cause premature failure in various components.
Additionally, I'm not sure about the driveshaft argument. My jeep runs around 2,200 rpm now and will run around 2,700 after regear at about 70mph. The impact in fifth gear is a 500rpm increase. Same for sixth. Since fifth gear is a 1:1 ratio and sixth is less at like .86:1 or something. aggressive power application will give a higher rpm for the driveshaft at higher engine rpm in a given gear, it will still be above 4,000rpm even with my current gear set. So, lets say I'm in second and trying to get up to speed quickly. Like at one of those crazy stoplights that lets you on the freeway. Anyway, if I hit even 3,500 I'm going to be above 4,000 at the driveshaft since my gear ratios for first through fourth are greater than 1:1. So really, the driveshaft will spin pretty fast most times. I'm not sure less than 1,000 rpm increase will qualify.

, I do appreciate the input there. However, I pretty much lost my warranty (by this logic) by having AEV put a lift on it since those driveline angles aren't exactly stock.

SilverSport 12-14-2012 09:00 PM

Quote:

Originally Posted by JKWrangler2012 (Post 3105126)
wow. lots to think about here. been wanting to change gears and add eaton provisions front and rear. if i were to add 4.10's and keep the factory size 255 75 17's.. would my warranty still be void? near ready to pull this 3.5k upgrade trigger and now a complete reality check.

Depends on the dealer. Some are mod friendly and some aren't.

JKWrangler2012 12-14-2012 09:08 PM

F... F me!!

should one call chrysler and ask if hiring a reputable installer with warrantied work... rubi spec final drive ratio and a tru trac with stock rubi meats out of spec?

InvertChaos 12-14-2012 09:08 PM

Quote:

Originally Posted by WXman (Post 3104153)

Like denial by two dealers plus Chrysler to honor warranty on other drivetrain components such as driveshaft joints when they went bad. Ended up without my Jeep and fighting with Chrysler over it for a while. Really big headache. $900 headache. Fool with your gears and kiss your drivetrain warranty goodbye because you put everything connected to them out of factory specs. To me it's not worth it.

$900 u joints?

Quote:

Originally Posted by WXman (Post 3105043)
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.

They won't be spinning any faster if you put on larger tires. My driveshaft in my TJ with 4.56s and 33s is spinning the same speed as the stock Rubicon on 31s, and slower than a stock 4cyl on 29s.

SilverSport 12-14-2012 09:10 PM

Quote:

Originally Posted by JKWrangler2012 (Post 3105366)
F... F me!!

should one call chrysler and ask if hiring a reputable installer with warrantied work... rubi spec final drive ratio and a tru trac with stock rubi meats out of spec?

I think you already know the scripted answer Chrysler will give you.

Here's the deal: if you mod your Jeep your warranty isn't automatically voided regardless of what a dealer says. But here's the catch. If they suspect one of your mods caused a factory part to fail, they don't have to warranty the factory part.

JKWrangler2012 12-14-2012 09:13 PM

c r a p

SilverSport 12-14-2012 09:17 PM

Cathode ray analysis programming?

JKWrangler2012 12-14-2012 09:22 PM

not sure if i can wait 4 more years to get out of 3.21's. they adequate. but i know what i'm missing. i've driven it. and i want it! F. will see the dealer next week when they replace the carpets... right.. like i haven't caused enough trouble over the leak?? lol.. actually i gave them a great review, they thanked me personally for it. but. damnit. if i wasn't nervouse over the pentagod... :sigh: :: finishes killians ::

SilverSport 12-14-2012 09:28 PM

Recon the dealer and get a feel for their thoughts on regearing, etc.

JKWrangler2012 12-14-2012 09:35 PM

Quote:

Originally Posted by SilverSport (Post 3105461)
Recon the dealer and get a feel for their thoughts on regearing, etc.


"we got that rubicon in you were asking about"

SilverSport 12-14-2012 09:37 PM

You asked about a Rubicon? LOL

JKWrangler2012 12-14-2012 09:44 PM

i drove it!! all over.. mw3. wasn't worth the 100$ monthly payment increase. selectable lockers @ 10mph and <. hell... my open diff jk sport is a rubicon until ten miles per hour.... i want true track rear.. e-locker front. 4.10's. f

scubatech 12-15-2012 08:45 AM

I really don't think anyone at a dealer would know that you changed the gears. It will be at the dealer very seldom anyway.

rvator 12-15-2012 09:17 AM

The dealer will never know if you regear or not. Most test drives that a tech will take will be on city roads and not much over 45 anyway. It's not like they will go down the interstate at 70 or more. Mod your jeeps now and enjoy them, for me the resale is good enough I am ready to sell and get a different one way before the warranty is gone.

JKWrangler2012 12-15-2012 12:07 PM

who can update the system for correct speed/o dometers after the change? dealer? to compound things i purchased an extended B2B warranty at signing.

SilverSport 12-15-2012 12:09 PM

Quote:

Originally Posted by JKWrangler2012 (Post 3106885)
who can update the system for correct speed/o dometers after the change? dealer? to compound things i purchased an extended B2B warranty at signing.

You can. Buy a Procal.


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