Upgrading my 2002 4.0I6 manual from 3.73 to 4.56. 4inch lift and 33x12.5 wheels. Any surprises I should know about from someone else that did this upgrade?
Taking to the shop for the exact reasons you stated. I already have lockers in the back on my HD44 do you think my 30 upfront will be ok with lockers? I have read some mixed reviews
My D30 is holding up fine with stock shafts and 33s. If you are going to be running 35s I would eventually upgrade to chromos.
A buddy that I wheel with has taken his rig on some pretty gnarly trails here in CO with his 35s, stock shafts, and lockers. They held up very well. Thats not to say he didnt break ears. Ive been with him in 3wd basically. He just recently upgraded to chromos.
Check out his type of wheeling on post #10 http://www.wranglerforum.com/f282/tj-3-5-metalcloak-lift-1373162.html
If you got the $$, go for shafts as well. Just piece of mind. But youll definitely be ok with stock.
A buddy that I wheel with has taken his rig on some pretty gnarly trails here in CO with his 35s, stock shafts, and lockers. They held up very well. Thats not to say he didnt break ears.
They didn't hold up well on that trail in the pictures. I made it through the trail and then both shafts fell apart on normal street driving over the next couple of days. I will tell you that those front shafts were on my mind the entire trip. totally mentally exhausting worrying about them.I wouldn't try to convince anyone that stock shafts are ok on 33's, especially if the front is locked. Even on a moderate trail. It only works until it doesn't. Just my experience of changing out shafts 3 times. We all can be lucky for only so long.:beerdrinking:
Your 3.73 D44 locker will only work with a "thick" 4.56 gear set, just FYI. Unless you are super hard on it, the stock shafts will work in the 30. Of course going chromo is not a bad idea if you have the coin.
Luckily I have the 3.73 stock. I read with 33x12.5 a 4.56 is best and I don't have to start making any other mods. I plan on putting lunchbox lockers in front also since the only activate in 4wd. Shouldn't be able to tell they are there in 2wd
Hosejockey my mechanic told me I didn't really need to upgrade to 456 since I have a 373 because it plenty of power with a manual. Thoughts? It's almost 1600 for the upgrade and I think he just doesn't want me spending unneeded money. He is somewhat of a friend also.
Well, being in Kansas you may not feel it like we do with the mountains of Colorado. I can tell you that I noticed a difference going from 4:56 to 4:88. I couldn't imagine running 3:73's with 33's. as the old saying goes, ignorance is bliss. If you haven't experienced the difference, then you just don't know or feel that it will have that much of a difference. Once you make the change, you'll be like "why didn't I do that sooner!"
Upgrading to 4.56 gears should be considered mandatory. One of my previous rigs had 4.10 gears with 33s and was barely tolerable. 3.73s would be unpleasant at best.
What is the largest tire you don't foresee? Plan for that tire. I'm running 4.88, 6sp manual, in CO. Unless I'm starting uphill don't even use 1st gear, but the low end torque on trails, aired down and at elevations of 8000'+ is outstanding. Planning on 37's in the near future. But my rig is no longer a DD and is a trailer queen now... I paid $1800 for re-gear.
Ok I have question. I have '05 X auto running 31" tires...so if it's still running stock gears it should be 3.07. It drives fine and I have had no problems..then why is every one saying go to 4.10+, Is there something I'm missing? Hopefully this sheds some light on why we go to such high ratios.
especially with an auto, your transmission will have a hard time deciding if it wants to be in 3rd or overdrive and it can be annoying. as if gas mileage wasn't bad enough in stock form, it only gets worse with that gear set and tires, or bigger...we're talking about seeing single digits depending how you drive. then there's the loss of usable power.
but if it's worth the effort, gear change means new components and hardware. but for me, cheap is always a priority, so i swapped out the axles in my tj for a rear from another tj with a 4cyl and 5spd, the front from an xj with a matching 4.10. $350 for both to bolt right in.
Ignorance is bliss, in this case. A gear swap will make a very noticeable difference, especially with 33's. Less downshifting with a manual, no more gear hunting and downshifting/ upshifting with with an auto. Off road you can creep along and climb without having to bury your foot in the gas pedal.
If you can live with your current set up, more power to you. If you want to optimize your Jeeps set up, a gear swap is needed.
33's with 4.10 gears is intolerable, 5th gear on the AX15 is unusable unless it's on flat ground at 55+ mph. Would imagine 3.73 you'd just about have to get out and push. Do yourself a favor and find a gear ratio calculator online. Plug in all your info with stock specs(tire size, gear ratio's), then do the same with the 33's you plan on installing. Find the gear ratio that will bring you as near back to stock specs as possible. I know on mine it's going to be near a 5.13 gear. Or you could use this math equation to figure it out, Old Gear Ratio × New Tire Size ÷ Old Tire Size = New Gear Ratio.
The 3.07 is only a guess. The PO has done some mods. So as far as I know, I'm running 4.10 on 31-10.50. And the tires have maybe 4K on them so going to 33"+ is a long way away. Besides around here it's either ~25 mph or 50+ and the transmission doesn't really do the "gear hunting" you are talking about. Maybe I got better gears.
One way to find out exactly what gear ratio you have is, put a piece of tape on the inside of your tire to make a line pointing up and down, then a piece of tape on your drive line point forward and back. Rotate the shaft while counting turns of the shaft to make one full revolution of the tire. For example the driveline rotates 4 times to make one full rotation of the tire you have 4.10's.
33 with 5spd and 4.10 is not at all intolerable in my wife's 04 Rubi and that is in the mountains. Town is just over 5000 feet and home is over 7000 feet above sea level and OD works fine. Ain't the ax-15 but is about the same
My 98 sport has 4.56 and the AX-15 and 33 for summer tires and for commute on highway I like the the 4.10 Rubi better
Intolerable is in the eye of the beholder but from the perspective of someone with regular access to both a big over statement
33's with 4.10 changes your diff gear ratio to 3.36 and that is a good highway gear, not so fun around town or on the trail and, really would like a better explanation of why you would like the 4.10's over 4.56's since there's what a 200 rpm difference hardly noticeable I would think.
You like your setup that's fine, intolerable in my expectations. Do believe that highway speeds were mentioned in my post and, no I wouldn't know if the slushbox trans is the same as a manual. Couldn't conceive owning an automatic myself. As far as your perception of what is a big overstatement, you might want to talk to the thousands of other folks that own Jeeps that would agree with my statement. But, thanks for your input.
I've tried to read all of the gear ratio threads on here and anywhere else i could find to help me make a decision. My jeep is an '00 Sport with 4.0L, NV3550, 33 x 12.50 x 15's, and 3.73's in a D-44 in the rear and the D-30 up front. It spends a lot of time on the freeway going on road trips, but when i take it off road it is crawling on the rocks and up and down steep rocky inclines. I am seriously thinking of swapping in a 32RH auto with a manually activated OD (switch on the shifter) for when i off road (just my preference). I'll live with it on the freeway without the overdrive. Digger, what do you think? Thank-you guys and sorry if this is a thread hijack.
The intolerable conditions I was speaking of was 4.10's with 33's never compared 4.11 to 4.56 that was you. I will stand with my description on intolerable 4.10's and 33's. When one gets the opportunity to operate a similarly outfitted Jeep with 4.88's or even 5.13's the difference will be day and night. The motor and drivetrain will not have to work near as hard to move the truck down the road. The engine will be up in a decent RPM range to get the best performance. MPG's will likely increase depending on your driving style. Guess we will just have to let the OP decide what he want's to do as it is his rig. Then you and I will have to just agree to disagree.
$1600 sounds reasonable. I paid $1800 to have mine done. One by-product of the re-gear you might watch out for is drive line vibes at higher speeds. Your drive shafts will be spinning faster than before, and if your drive shaft operating angles are approaching max angle, that little extra RPM could send them over critical and cause a vibration. If you have a SYE and double cardan rear drive shaft you'll probably be fine. I don't, so now I'm experiencing vibes above 60 mph after re-gearing.
Vibrations occur due to poor DL angles, not increased RPM's due to a gear swap. You had vibs before the gear swap, whether you felt them or not. The gear swap simply put the vibs into a speed range that is more noticeable to you now.
Good idea to check your u-joints for excess play. A driveline re-balance might be a good idea. Of course if you are lifted a SYE/double cardan shaft is probably needed.
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