Re-gear: Final questions before install

chino1969

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O.K., one last time for any input and for confirmation I am making the right decision. I have a 2004 TJ 4.0l, NV3550 5 speed trans. with 33" tires and 3.73 gears, Dana 44 rear, Dana 30 front. Shifting on the road is less than desirable, especially going up hills. This will see some off road like forest trails and moderate off road use. This will be my daily driver for awhile, I live in PA where we get snow. I have decided to go with 4.56 gears and a Detroit Tru Trac LSD in the rear. I was going to go with an auto locker in front but changed my mind when reading about the handling quirks in the snow, so the front will remain open diff. until I see a need to do something different. I can't justify air or electronic lockers for my intended use. I believe an LSD in the rear will do everything I expect or need. Any opinions greatly appreciated. Understand I am very pragmatic and don't need to spend money where it is not needed. Thanks.
 
Grimmjeeper.com

Your tire diameter is the hub height x2
 
I have 33's with 3.07 gearing, 5spd 4.0L. when I regear I think I'll go with 4.88. I don't want to go higher than 33's. It's my camping/fun vehicle, so I will deal with the 307's as long as I need to
 
I started with 4.88 and 33s and loved it. I now have 4.88 and 35s and I wish I had 5.13 or even 5.38(I hardly go over 70 anyway). nv3550 trans.
 
Many have recommended 4.46 as I've asked many questions and done a fair amount of research. I'll ask these questions from those who now recommend 4.88 gears over 4.56:
1) What would the advantage(s) be?
2) Would there be a significant amount of difference to notice?

Understand I have already talked with the shop and made the appointment. Anyone who is in favor of 4.56 gearing over 4.88 I would appreciate your opinion; especially Jerry Bransford or Mr. Blaine. I'm looking for a bit more in depth reason. Thanks.
 
Mine is a daily driver, and 4.56's work well for me. I won't go bigger than 33's, so the 35 scenario is irrelevant to me. Not to scare you from re-gearing, but some who have re-geared have experienced harmonic vibes as a result of faster drivetrain speeds post re-gear. Going too deep could exasperate the condition. Just my 2 cents.
 
I vote 4.88. Have you considered putting trutracs front and rear? I personally would either put a locker or a lsd in the front while they are regearing it to save money on labor.
 
Many have recommended 4.46 as I've asked many questions and done a fair amount of research. I'll ask these questions from those who now recommend 4.88 gears over 4.56:
1) What would the advantage(s) be?
2) Would there be a significant amount of difference to notice?

Understand I have already talked with the shop and made the appointment. Anyone who is in favor of 4.56 gearing over 4.88 I would appreciate your opinion; especially Jerry Bransford or Mr. Blaine. I'm looking for a bit more in depth reason. Thanks.
Lower gearing off road, important on a manual trans. A bit better take off. Couple hundred rpm more at cruising speed so less downshifting. Better gearing if you ever go larger than the 33. 4.56 will work well, too, 4.88 just a bit better.
 
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I have the same set up, but my trans is AX-15 5sp. Mine is a dailysh driver, and I am a 4:88 wth 33's also. I don't plan on going any bigger than 33's.

Not trying to sell you anything just letting you know what others ie me are running. I am quite satisfied with my gearing.

My story is I had a Ford rear end built by a shop for my TJ, My intentions also were 4:56's. I then bought new gears and locker for the front and installed them myself, only to find out that the shop accidentally put 4:88's in the rear. Once I figured out their error, they said they would switch them to 456, but after having been driving around with 4:88's and not even knowing it. I just had them change the front to match instead. So in the end I ended up with 4:88's. I am happy with them.
 
I vote 4.88. Have you considered putting trutracs front and rear? I personally would either put a locker or a lsd in the front while they are regearing it to save money on labor.

Am considering Tru Trac front & rear. Will talk to shop tomorrow. Am definitely going with rear right now. Thanks.
 
Lower gearing off road, important on a manual trans. A bit better take off. Couple hundred rpm more at cruising speed so less downshifting. Better gearing if you ever go larger than the 33. 4.56 will work well, too, 4.88 just a bit better.

Thanks. Will never go larger than 33". After having driven it all summer with 33" tires and 3.73 gears I found the gearing to be less than adequate. Too much shifting too quickly. Not compatible with the type of driving I do as this will be a daily driver for awhile. From reading and research the 4.56 gearing sounds right but will talk it over with shop. Compare two vehicles side by side both with 33" tires everything the same. One has 4.56 gearing, the other 4.88 gearing. Would there be that big a difference between the two to warrant the 4.88 gears?
 
Lower gearing off road, important on a manual trans. A bit better take off. Couple hundred rpm more at cruising speed so less downshifting. Better gearing if you ever go larger than the 33. 4.56 will work well, too, 4.88 just a bit better.

I always get this ass backwards so please bear with me. When you say: Lower gearing off road, important on a manual trans. A bit better take off. Do you mean the lower gears will move the vehicle faster or slower off road? Less shifting off road as well as highway? I'm tired of shifting so many times to travel locally, downshifting to go up hills, up shifting because my rpm's are getting high and the trans. is screaming. I'm hoping the 4.56 gears will improve my ride by eliminating these short comings. If I were never driving this on the highway I would stick with 3.73 gears but want the best of both worlds; on road highway and moderate off road. Sound right?
 
4.88 is lower gearing than 4.56. Think of the larger number as a longer lever.

I'll add that when I move to 35" tires, my hope is to change my existing 4.88 to 5.13. And the funny thing is that the rpms will still be lower than my current setup with 33s.
 
I had the exact same setup as you and went with 4.56, a Detroit in the rear and a lockrite in front. I also said I would never go to 35s, and then I did after about 6 months. 4.88 would've been a little bit better with 35s, but it's still pretty good at 4.56. for me the 4.56 is just right for 33s.