Just FYI, the '05 and '06 model TJ's have differently geared transmissions, which helps me out a little bit as well. See the difference below between the AX-15 and the NSG370:
AX-15 (5-speed):
1st - 3.83
2nd - 2.33
3rd - 1.44
4th - 1.00
5th - 0.79
Rev - 4.22
NSG370 (6-speed)
1st - 4.46
2nd - 2.61
3rd - 1.72
4th - 1.25
5th - 1.00
6th - 0.84
Rev - 4.06
The difference of . 04 at 70 is 2100 vs 2230.
4.10 would have got you to 2454 which would been conservative but better. 4.56 would have been 2700.
I would bet dollars to donuts 2700 rpm at less throttle input would have been better mpg.
taking unsafe rigs to a whole other level
I'm surprised ECGS sold them to you with those gears...hopefully they questioned you and offered some advice.
Why is it their obligation to do so? They sell a ton of rears for stock replacement. If your buying a rear end you should be competent enough to make big boy decisions and not require a babysitter. If you order online just check the boxes, why would they inquire as to end use if the individual doesnt inquire.
97 XJ Clayton Longarms 35s locked etc.
94 YJ MTO
98 5.9 ZJ Limited alllll original
02 Cummins 6spd HO Studs, Sticks, Box, Pump...
I have to admit, I don't understand the fixation of what our jeeps are doing at 70mph. 95% of my driving time is spent at 60mph and below, with the vast majority being in the 40-50mph range. Plus, I have never done 70mph off-road... Not that it doesn't sound fun! I think I would choose a different vehicle if I spent that much time doing 70. Or potentially change my gearing to something like 4.11 or 4.56.Originally Posted by 2002wranglerX
RPMs are only part of the picture. If you look at a dyno chart for the 4.0, there's about 9-10 hp difference between 2200 and 2700RPMs. And if that much of a difference sucks, a few engine mods should overcome that. You also have to look at final drive ratios. If we were to take your jeep and my jeep, put the same tires on them, and give you 4.11s front and rear while I had 3.73s front and rear, I would still have better final drive ratios than yours because of the transmission. My final drive ratio will compare to around 4.34:1 in a similarly equipped TJ from before 2005. That falls almost dead center between 4.11 and 4.56.
I spoke with ECGS, a lot. I didn't just blindly dump a ton of my hard earned money on random axles. I put in more research and effort than just asking a few people what gear ratio I should use. I also didn't just go with the "common wisdom" of the internet and over gear it to the point 1st gear is useless. But hey, thanks for your input.
Sounds like lots of math and not a lot of first hand experience.
I wish you well. You certainly stepped up on some decent axles.
taking unsafe rigs to a whole other level
On Thursday I towed my quad on my 14’ trailer from latrobe to delmont so my dad could use it for hunting. The Jeep could barely handle 3rd gear on the flats and loved 1’st and 2nd on any type of hill... there’s your gearing example. Once the trailer was off the Jeep maintained 60mph and an unbelievable 21mpg on the way to my camp on Friday. It’s amazing how good it can seem to run until it has to do some work.
Rear is done, I drove it long enough to back out and pull back in to my garage and then started tearing into the front. I'm almost done with the front. Just need new hub bolts (seriously, why don't they ship with new ones already??), which I'm picking up today. My goal was to have it finished by today, but I think I'll run a bit over because of the wait for hub bolts plus I've been fighting a nasty cold. Either way, I'm satisfied with how much I got accomplished. I'll get some pictures up tomorrow.
I hate the unit bearing bolts. I honestly think thats the first thing I've done to every new to me Dana 30 I've ever acquired is remove those bolts clean them up and slather them in antiseize. I have a box I started to toss ones in from junk housings etc. To have extras haha
97 XJ Clayton Longarms 35s locked etc.
94 YJ MTO
98 5.9 ZJ Limited alllll original
02 Cummins 6spd HO Studs, Sticks, Box, Pump...
Those bolts suck. I have a 12 point 1/2 inch socket I tap onto the really crusty ones.
The new ones from napa are hex heads, so hopefully I'll have less problems with them if I should ever need to replace them. I'm still a bit concerned though because they're a bit longer the the original bolts. But they clear, so I guess it'll bee alright. Still debating about the rotor dust covers. It's like $50 for a new set and I'm struggling to see the benefit of having them on.
Ya, I would switch mine over to hex head, and you will be fine with ones that are longer as long as they don't touch the spinning hub. Screw the dust covers.
It clears, just closer than the old ones:
I threaded an old one in to show the difference:
Anyway, here's a shot of the axles finally installed. Just a few things left to button up. My only disappointment is that the front doesn't look as good as the rear. But then again I don't have the money too swap all of that out with brand new parts. Besides, in a year or two, it'll all look the same.
I've only ever had 1 vehicle have problems after removing the dust covers. But that was a Ford and I think they designed those trucks to completely rust out on purpose (Sorry Ford fans). It's more aesthetics than anything... Well, that and not wanting to drop another $50 on a part I have to replace because of rust.
Every Jeep I've ever worked on, had to have it apart, the dust covers got chucked in the scrap bin.
97 XJ Clayton Longarms 35s locked etc.
94 YJ MTO
98 5.9 ZJ Limited alllll original
02 Cummins 6spd HO Studs, Sticks, Box, Pump...
Looks like it's coming along!
taking unsafe rigs to a whole other level
Didn't have much time to wrench this weekend, but I got a few more items ticked off my list. I swear the only way I'll get done is if I take a day off work and not tell my wife about it. LOL
It looked like you had a good chunk of the work already done in the pics. What all do you still need to do? If your anything like me I wouldn’t recommend making it driveable until the very end, once it moves I never finish anything else lol.
Right now I only have to reconnect the diff vent, put the tires back on, check alignment, adjust the rear parking brake, and double check everything to make sure I didn't miss anything. This weekend, I torqued all of the front suspension, filled the front diff, put the second hub on, and reinstalled both sets of rotors and brakes.
It's alive!
Finished up all my checklists, took it off the jackstands and put about 30 miles on it... Only 470 more to go before the new axles are broken in. That should only take like 3 months. lol
Awesome! How did it drive with the new locker?
To be honest, I haven't noticed much of a difference in drive-ability. Obviously, the front locker has no impact in 2WD, you'll just hear the occasional popping from the Spartan locker. The rear LSD will kick out the rear occasionally, but I'm used to it from other vehicles with a Limited Slip. I've only done a little bit of 4WD time thus far (still babying it during break-in), and all of it has been low speed. On tight turns, it does try to go straight for a little bit. But if you goose the gas pedal, it'll turn. I'll have to play more in 4WD and let you know (hopefully we can get some snow I can play around in). I'm still getting the feel for the new gearing, locker, LSD, and lift so it's a little hard to analyze everything at once.
Went through some deeper mud tonight, in 4WD, still low speed... Turning wasn't an issue and traction through the mud was great, even with my crappy little all-seasons. So far, there's been no downside to the locker up front.
300 miles into the 500 mile break-in and everything's going good. Drove in the snow this weekend in both 2WD and 4WD and I can tell you that the only difference I noticed is the turning radius is larger in 4WD with the front locker. But as far as making it impossible to drive or the vehicle not turning just didn't happen to me. Maybe it's the difference in driving styles, or maybe the fact that I have a limited slip in the rear as well, but I don't understand why people complain about locking the front. If you're on the fence, just do it, you won't regret it.
Just ordered a new oil pan and gaskets. I was amazed at how rusted that thing is... It looks paper thin right now but it still holds oil, so hopefully it lasts until I can get back under there! From what I've read, you have to drop the y-pipe to swap out the oil pan; So it looks like I may add a set of headers and new muffler while I'm at it. If I go that route, I'm going to try and wait until spring to replace the oil pan (to save up some more money).
Speaking of mufflers, has anyone used the Magnaflow cat back turn down style muffler? It basically ends before the rear axle, instead of having that pipe snake its way through to the back of the Jeep. Any thoughts?
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