For those of you looking to keep your Jeep JK Wrangler relatively stock and have no plans of installing tires larger than 33″ but would still like to regain some of the power you’ll loose from them, Superior Axle & Gear has got the answer for you. Last week, I got to watch the very first set of Superior Axle 4.56 gears getting installed into Brett Woods’ (aka – Woods) 2007 Jeep JK Wrangler Rubicon Unlimited and after giving them a thorough break in, here’s what he had to say about them…
Just wanted to give you a little feedback, now that I’ve had a little time on the gears. I now have almost 500 miles on them, and Mel took a look at them yesterday. The wear patterns look great, and it looks like they have blessed the gears for production.
Now for the good stuff. I have been running 33″ tires from about the 100 mile mark on my JK. This given, I didn’t think that there had been much of a difference between the stock 32″s and my 33″ tires. Now with the 4:56 gears, I realize that there is a difference. I now have more power in every gear. I don’t find my self having to downshift while driving through the hills at freeway speeds. These gears are much better for cruise control. My biggest surprise though, is the increased effectiveness in second gear. The JK has a low first gear, and it needs it. First gear driving is not practical for trail driving, however. When trail driving with the 4:10’s I found myself having to downshift from second gear most any time that I came across anything technical, rocky, rutted etc. Basically If I had to drop my speed below 6 miles per hour, I had to downshift to first gear. I’m really pleased with the new flexibility of second gear. On a trail this weekend, I was able to drop down to 4 MPH, in a fairly technical section, without having to downshift to first. Call me lazy but, I’m really stoked on how the 4:56 gears have improved my trail driving experience. For anybody running 33″ tires, the 4:56 gears are the perfect solution.
Brett (aka – Woods)
If you would like to see a few pics of what these new gears look like, click on the link below:
Superior Axle & Gear Jeep JK Wrangler 4.56 Gear Pics
And, if you would like to get a set of these gears in your Jeep JK Wrangler, they can be purchased from most of our sponsoring vendors including 4Wheel Drive Hardware, Northridge4x4, Off Road Evolution and Quadratec.
Eddie
Special Thanks: I would like to thank Superior Axle & Gear and for giving me the inside scoop on this much desired new Jeep JK Wrangler product and Off Road Evolution (who did the install) for allowing me to observe the installation of these new gears. I would also like to thank Brett Woods for the use of his Jeep to have these gears installed in and for testing them out for us.
What’s the cost for this gearing installed.
Depends on who you take your Jeep to but on average, you would be looking at about $1500 or so.
Eddie
I have a few questions for you. I recently installed a 3 1/4 rusty’s off road lift on my 2007 JK 2 door X and it is sitting on top of a set of Mickey Thompson Baja 35 12.5 17’s. All the warning lights are out and the truck is handling better then I expected except when I take certain turns. A typical left or right turn is not a problem but long turns like you find going up mountain roads or some interstate ramps are a big problem. What happens is the traction control activates. The light flashes and it starts applying the brake to whatever tire it thinks is slipping. This is happening at low speed. The brakes pedal starts to pulsate and to say the least it is a little nerve racking. Have you heard of this problem and do you have any idea on how to fix it or disable the traction control assist all together??? The other problem I have for you is gears. I have the dana 44 in the rear and the dana 30 in the front. I don’t know if I should change the gears or not and if I should what size to go with?? Keep in mind this is my daily driver so I need it to handle good both on and off road. Thanks so much for your help. This website has answered so many questions and has given me some great ideas. I can’t thank you enough for all you guys do.
I’m running 33s with the 6spd and 4.10s. I definitely need more power, especially in 6th on the highway going up hills. I’m at about 2500 rpm now. Seems to me going with 4.56 would bring me into that ‘drone’ range of 2800-3000, right? Hmmm… Let’s say all parts were free, would you go with a the 4.56, or a Supercharger with 4.10s, or a Supercharger with 4.56? 🙂 And would you go for the Hesco or wait for the Avenger? 🙂
Thanks Eddie!
js.
Hey js, honestly, I might just go with 4.88’s and call it a day. At least, that’s kind of what I did only I got 5.13’s to go with my 35’s. Made a world of difference 🙂
Eddie
I have a quick question. I just picked up my 08 Sahara Unlimited. It is an automatic with 3.73 gears. This is my first Jeep, and my first non V8, so I am still trying to figure it out. However, I have noticed that on the interstate at 70 mph it keeps wanting to shift out of overdrive. Is this normal from the Jeep? Also, I am putting 285/75/16’s on it and am concerned it will make the shifting worse. Any suggestions? Thanks.
Hi Tim, I apologize for not responding to you sooner. I had been in Las Vegas attending the SEMA show all last week and just got back in late last night. Regarding your question, yes, with 3.73’s and an auto, this is kind of normal. If you get larger tires, just make sure to use something like an Accu Pro to recalibrate your speedometer and that should help keep things the same as they are now. If you want an improvment on power and shifting, you will need to regear.
Eddie
Eddie
Thanks for the response. In regards to the Accu Pro, which one is used for the Jeep? They only list Dodge and none for the 3.8. Any suggestions. Also, do you think the Jet chip and a cold air intake are worth while? I would like to gain a little bit of power.
Hi Tim, there is no Jeep specific Accu Pro at this time but can tell you that the 5.7L HEMI one will work. Just use this write-up to help you find the part you need:
http://project-jk.com/jeep-jk-write-ups/pro-comp-accu-pro-jeep-jk-wrangler-speedometer-odometer-calibrator
Eddie
Hi i have an 08 JK 6 speed runing 3.21 getting 17.5 MPG with pizza cutters. I wan to install 2.5″ lift an put a set 33″ tires on. I know i will have to regear but 4.56 seems to be to drastic of a change from 3.21. I was thinking 3.73 or 4.10. It seems with 4.56 that fuel mileage would drop below 15MPG. Any idea’s? Thanks for your time and effort on this matter.
My JK is auto with 4.1 gears. I am not happy with its crawling performance (crawling ratio is 31.7 very low). Keeping the stock tires, should I regear to 4.56 or 4.88?
Where can I buy the 4.56’s? could’t find in Northbridge, Quadratec etc.
Meir, if you’re looking for a better crawl ratio, you might want to hold out for MOPAR to release their 4:1 transfer case upgrade. That’s where you’ll really feel the difference. Otherwise, if you still want 4.56’s, call Northridge4x4 at 360-340-0282 and ask for them.
Eddie
Hi Eddie,
Thanks for the quick response.
When the Transfer case upgrade will be released? any estimation about $?
Will it be internal unit or an add-on external unit?
Don’t know for sure… maybe some time this year. As for cost, I don’t know that either but since it’s just replacement components for your t-case, I would imagine about $500 or so.
Eddie
Eddie,
As Northbridge doesn’t have 4.56’s, I’m thinking about 4.88’s. It will increase power by 19% at low speed, while increase RPM from 1950 to 2300 at 65 MPH, which is reasonable (and similar to the Manual transmission at 6 gear, with 4.1’s). Am I right?
Yes, you are right and is something I personally would do.
Eddie
I have a 2008 Sahara with 3.73 gears and live in Colorado. Is there any gear ratio between the 3.73’s and 4.56 for this application with the Dana 30 out front? What kind of rpm’s will this run in 3rd and overdrive in the AUTOMATIC @ 55 miles per hour? Do you have part #’s from Superior? I would like to regear and have the local dealership do it. In your opinion is the 4.56 to low with the stock 32 inch tires for this application? Jack
I have a 2006 TJ with a procomp 4″ lift and 33″ tires. I am tired of the transmission shifting on every little incline. I want to ditch my 3:73 gear and change it, but I don’t know which gear to get 4:10 or 4:56. My jeep is a daily driver that I take offroad only for hunting season. Which gear should I go with? Thanks!
Mike
If you have 33″ tires, you will want 4.56’s as they will get your Jeep running at it’s optimal performance power and MPG wise.
i have a 2007 jk with a 3in lift and fixing to put 33×12.50. 4.56 seems to way out there compared to my 3.21 that my jeep has. is there anything im over looking that makes 4.56 optimal for these tires. would 3.73 be better for daily driving and what kinda of rpm change am i looking at. daily driver and weekend off roader
Hi edgar, trust me, 4.56 is an exact match for 33’s and if anything 3.21’s are on the high end of things – mainly intended for gutless power and gas savings. However, if it were up to me, I would highly recommend going all the way up to 4.88’s. They will burn a bit more gas but man, you will feel a ton more power out of your JK.
Eddie
thank you eddie, one more question. speedo. will that change and tach. what do i do with that.
if you are refering to your shift points, yes. your tach measures your engine revolutions and not your speed.
I am having the 4.56’s installed to mate with my 5.7l Hemi and 35’s. I’ll let you know how the beast responds. have 4.11’s now. no rock crawling down here in bayou Louisiana, only mud and hills, so 4.88’s or 5.13’s aren’t neccessary. I do mostly city driving and a bit on the hwy. Long trips are in my BMW 550i Sport.
2 questions. if i install these gears in my jk, what are the rpm’s at 70mph in 6th and will it though my speedometer off.
Yes, your speedometer will be off but assuming you have 33″ tires, it will be off already. as far as rpm’s go, with 33’s, it should be about where your Jeep was at stock.
I have a 08 JK X. It’s got 3.73’s, I’m running 35″baja claws, black diamond 3″ lift and a 6 speed manual. I have for the most part lost 6th gear with the 35’s on there. I am thinking of going a little higher (6″ lift) and 37 or 38″ tires. What gear’s should I put in to compensate for the tire’s 35’s and 38’s? Also, will I need to change the axle’s and/or drive shaft’s? Thanks a ton for your help.
p.s. It’s a daily driver and I’m getting about 12 miles a gallon as it is now.
hey hows it going ,I own a jk unlimted with 4 inch lift and 35″ tires .what gears should i be running ive gone through second clutch want to get the right gears before I tear up another .
what ring and pinion should i use thanx rey
for 35″ tires, i would go with 4.88’s
Hey im thinking about putting on a set of 35″ mtz on my manual 08 jk. Is it totaly out of the question to NOT change my gears?
not at all. i’m still running stock 3.73 gears with 35’s on my orange jk and surprisingly, it’s not too bad.
Right on. That was a big concern that i had. Thanks for the quick respons.
09 JK X 4dr With the auto & 3:73’s, I’m wanting to run 33’s possibly 35’s later on. It is a daily driver with as much time on the Interstate as well as around town and on the farm. Light off roading ocassionally. Looking for something practical but not to week. Fuel economy is obviously a concern, but which would be the best all round performer and still be fairly streetable on the Interstate, 4:56, 4:88, or even 5:13’s like it’s been strongly suggested? This does not have the lower geared transfer caes of the Rubicon, so what would you go with?
for your purposes, 4.88’s would be your best bet.
Thanks for teh quick reply!!!!!! I was thinkin 4:56 but was worried it would seem to stock & sluggish with the 4:56’s on 35’s, thanks!!!!!!!!!!!1
I have an 08 Jeep JK Unlimited X. I put a 2.5 inch lift and 33 inch tires. I would like to change the gears to give me a little more power on the interstate. It has 3.73 now. Would you suggest 5.13 or 4.88? Thanks!
if you’re planning to stick with 33″ tires for the long haul, i would recommend 4.56 gears as that would be the correct ratio you need. if you think you might go 35’s in the future, 4.88 is definitely the way to go. of course, if you’re just looking for more power, 4.88’s is still the way to go and i think you’ll be quite happy with them.
just wunderin with a 3inch long arm kit and 35,s will my stock 4.10 work well on highway ps great site
yes, 35’s and 4.10 are totally doable.
I have a 2011 JK Wrangler unlimited Sport 4 door and its automatic 3.8L V6. Right now I have 3:73 gear ratio with 32s came like that from the dealer. I have the next generation dana 30 solid front axle and next generation heavy duty rear axle. Would I be able to run 35s on it? Also my wife drives it to work every on highway, city driving and, we do moderate off road ie;rocks,mud,sand,snow,and small river stream. Any recommendations thaanks.
sure you can run 35’s but, with 3.73’s, you will feel a little power loss but, nothing too much. i ran this setup for about a year and found it to be tollerable. with 35’s i would recommend having some c-gussets installed as your axle c’s will bend without them.
I have a 2008 Sahara Unlimited with manual trans and am not sure what my gear ratio is. I am assuming that it is 3.73 because I think this is the year they switched from 3.21. I am lifting and putting on 35’s. I don’t think I will go up to 37s but only the future knows…in that case should I regear to 4.88 or consider 5.13. This is my DD and I do a fair amount of hwy driving but also want the torque and hp available if I tow and offroad. Thanks for your two cents.
I’d like to do a gear swap on my 07 Sahara Unlimited. I’ve installed a 4 inch lift suspension and 1 inch body lift. Want to put 37’s on. Looking at 4:88 now unless somebody gives me a better idea. (It is an automatic).
Also, where is a good source to research the original equipment so I know OEM Axle (splines)/gear ratios, etc, as I’m not sure what fits into my diff covers and onto the axles.
Thanks for your time.
hey guys, i have a 2010 jk sport, put 265/70/17 on them. my rear is 3.21 I dont do offroading, should i be concerned about blowing my rear or it should be ok? Dont really care about power. After all its a jeep, not a sports car. Thanks
You should be fine.