Diff. Gears

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Welp...just dropped the Jeep off at my local gear shop. By this time tomorrow I will have 4.56 gearing! Really looking forward to the differences coming from 3.73 with 37" tires.
I did it…big difference! Backed off on my PC a few notches. Very noticeable off the line, but it really helps in the mid power band in my opinion
 
I did it…big difference! Backed off on my PC a few notches. Very noticeable off the line, but it really helps in the mid power band in my opinion
Before the regear I had done several torque launches which were amazing even with the 37s…after the regear I can chirp all 4 tires doing a torque launch, 37x13.5x20, very heavy set up. The 4:56 gear marries up so well our engine
 
Welp...just dropped the Jeep off at my local gear shop. By this time tomorrow I will have 4.56 gearing! Really looking forward to the differences coming from 3.73 with 37" tires.
Am very interested in your results. Are you using Dana Spicer 44 @ 4:56? If you don't mind sharing what are they charging you? I assume you are keeping all the OEM drivetrain and axels. I know @BenLandry did that and it sound like I may follow you guys when I trade up tire sizes eventually. Keep us posted.
 
Am very interested in your results. Are you using Dana Spicer 44 @ 4:56? If you don't mind sharing what are they charging you? I assume you are keeping all the OEM drivetrain and axels. I know @BenLandry did that and it sound like I may follow you guys when I trade up tire sizes eventually. Keep us posted.
My guy was a little expensive but was highly recommended in the Houston area. All they do are gears and axles. I was about 2800 out the door using Dana Spicer.
 
Am very interested in your results. Are you using Dana Spicer 44 @ 4:56? If you don't mind sharing what are they charging you? I assume you are keeping all the OEM drivetrain and axels. I know @BenLandry did that and it sound like I may follow you guys when I trade up tire sizes eventually. Keep us posted.
Yes...Dana Spicer 44 @ 4.56. I bought all of my gears and associated hardware ahead of time and had it shipped to me (I'll look for the receipt for the amount). The shop that is doing the work normally charges ~$120/hr, but since he does the work on all of our vehicles, he gave me a price of $1000 for the change-out/install.
 
My guy was a little expensive but was highly recommended in the Houston area. All they do are gears and axles. I was about 2800 out the door using Dana Spicer.
Worth paying a little more and doing it right first time. My shop botched my front 4.56 gear install on my jk. Had to get it redone. 😡
 
My guy was a little expensive but was highly recommended in the Houston area. All they do are gears and axles. I was about 2800 out the door using Dana Spicer.
I had a quote a couple of years ago for about 2800 for my LJR so with prices going up that sounds like a decent deal. I dont know, its the only time I have paid attention to how much it costs.
 
4.56 gears installed and all I can say is...WOW!!! I definitely notice the difference in ride quality, acceleration, and shift points. So very glad I went this route and big time thanks to everyone who contributed input along the way!
I think your trans will do some learning also and adjust itself to new gearing. So it will get better.:p
 
4.56 gears installed and all I can say is...WOW!!! I definitely notice the difference in ride quality, acceleration, and shift points. So very glad I went this route and big time thanks to everyone who contributed input along the way!
Congrats on your new 392XF! (Xtremely fast, or fun, or any other f-word) :)(y) or maybe it should be called an 392XX for Xtreamly Xtreme. Or 392XL for xtremely logical because you ended up with 37” tires, 4:56 gears and Fox Shocks for less $ than FCA wanted for 35’s, 4:56, with Mopar shocks. Thoughts?

I totally understand that the acceleration and shift points have changed but what changed on the ride quality? Thanks for the updates. It’s making me think about re-gearing. :unsure:
 
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I did the 4.56 re-gear on my standard 392 about two months ago. Total cost was about $2,000. I'm running 35's with everything else on the suspension stock, and the gears made a HUGE difference. I'm at 4,400ft elevation, and it will chirp all 4 tires on a non-brake launch. I'm very happy.
 
I really like my 35's.
I noticed the reduction in power when I went from 33-35
I think 4.56 is too much gear for 35's
Re-gearing to 4.10 sounds like a waste.

Indecision may or may not be my problem.
 
I really like my 35's.
I noticed the reduction in power when I went from 33-35
I think 4.56 is too much gear for 35's
Re-gearing to 4.10 sounds like a waste.

Indecision may or may not be my problem.
Keep in mind, the stock XR comes with 35's and 4.56 gears. That's the reason I went to 4.56. Plus it gives you the option to go to 37's in the future.
 
Keep in mind, the stock XR comes with 35's and 4.56 gears. That's the reason I went to 4.56. Plus it gives you the option to go to 37's in the future.
True, but 37 with 4.56 is still geared lower than 33 with 3.73
 
I totally understand that the acceleration and shift points have changed but what changed on the ride quality? Thanks for the updates. It’s making me think about re-gearing. :unsure:
What I meant by ride quality is the overall difference in having 37's and 3.73 differentials vs. 37's and 4.56 differentials. Acceleration from a standing start, getting up to speed rapidly or slowly, shift points, etc. - all of that (to me anyway) encompasses ride quality. As mentioned - very, very glad I pulled the trigger on this!
 
True, but 37 with 4.56 is still geared lower than 33 with 3.73

If you dont worry about gas mileage... the 4.56/35 combo is killer. Extremely responsive yet still docile on the highway.
I just went to 37s (measure 36") and feel 4.56 is about perfect for that.. as the first thing I noticed was my RPMs go down and my MPG go way up on the highway.
 
as the first thing I noticed was my RPMs go down and my MPG go way up on the highway.
So, way up to what? 12 MPG? Thats what I'm getting now. I'll have to look into gearing. The 35's slowed me down significantly. I'm very surprised.
 
So, way up to what? 12 MPG? Thats what I'm getting now. I'll have to look into gearing. The 35's slowed me down significantly. I'm very surprised.

17ish+ highway... up from 15.
More to come on it as I havent done a whole lot of driving with the 37s yet.
Ill get a real test at the end of the month with a 1200 mile drive to FL
 

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