re-gear questions

Gotta disagree with you Dutch.
Use the website I linked to in post #6

x2 - while I was always happy with my 4.30/5-spd/4.0/33's on the highway, I always wished they were a little deeper off road...:sunshine:
 
I guess my next question is what's a good "traveling" RPM (Long trip, highway) to shoot for?

The link that Frank provided is really helpful in figuring out what RPM you'll be running at but, being the novice I am, I'm not sure what's....good so to speak.

Again, I'm a manual transmission, NV3550 and NP231 and it calculated to:


4.56 gears in 5th gear - 2557 RPM @75mph
4.10 gears in 5th gear - 2299 RPM @75mph

I'm used to ruinning VERY low RPM's in my current setup at 3.07 gearing and rarely need to go above 3k RPM so this is all new to me. I'm well under 2k at 75mph currently.

Thanks for all the help everyone. It's much appreciated.
 
Except the limited in the front (and especially on a rig you can't disconnect the hubs) will steer like crap because the two driveshafts are always tied together. With a locker up front your turning radius won't be affected as badly because the locker will unlock and allow the two driveshafts to spin at different speeds. Been there, done that, and I'll take a locker up front and limited slip in the back over the oppositte anyday. Especially on a daily driver.

Negative Ghostrider, I ran a TruTrac for several years in my XJ D30 with NO steering issues!
 
Really? With an AX-15 and 4.56 gears on 36's I had plenty of pull for the highway, although admittedly I can't say much for offroad as I had a 4:1 t-case and never wheeled with the 36's, 4.56's, and a stock t-case. Maybe that was the difference for me. Still, on 32's and 3.55's I felt fine on the road and only wanted steeper gearing for the trail.

Mathematicaly you should only need a 3.77 gear ratio to be back to stock on a 3.07 equipped manual with 33's if you use 27" as the stock tire size. Now I know that doesn't account for extra weight and rolling resistance but tats why on an AX-15 I usually recommend 4.10's for 33's wich should also allow you to go up to 35's as mathematically that only calls for a 3.98 ratio to be back to stock.

A stock XJ (as per Novak's chart) is turning 2263.6 rpm at 75mph in 5th gear, with 4.56's and 33's you'd be looking at 2750.9 rpm at 75mph

Using Novak's chart and their identified OD of .78 for the NV3550 (AX-15 is .79) I'm showing 2716.09 rpm at 75mph with 4.56's and 33's. Thats a lot of RPM for prolonged highway use. Based on a 27" tire and stock gears the NV3550 should be running you at 2234.9rpmat 75mph.

As per Novak's chart my XJ (36's and 4.56's with an AX-15) comes out to 2521.6 rpm at 75mph and that sounds about right from what I remember and it did wonderful on the highway. Like I said, I was running a 4:1 tcase so I have no comparison for on the trail with a stock tcase.

Keep in mind to that for him his NV3550 has a 4.01:1 first gear so with only 4:10's and 33's his crawl ratio (1st gear and 4low) will be a 45:1 compared to a similarly setup AX-15's 43:1. Stock the AX-15 rig was only at 32:1 and the NV3550 34:1, so either way a fairly nice improvement with 4.10's and 33's.

My XJ was sitting at a 70:1 crawl ratio wich I found way too low on regular trails and only appreciated on the larger obstacles, I also found it to be lacking on the really tuff stuff. On easier trails I was constantly going back and forth between 4hi and 4 lo because I was running out of rpm in 5th gear/4lo trying to keep up with people.

My current rig has a crawl ratio of 46:1 in 4lo and 122:1 with the crawl box engaged.

His rig with 4.56's would have a 50:1 crawl ratio, so while that would be great on the trail I don't think its worth pushing 2700+ rpm on a daily basis at highway speeds.
 
A stock XJ (as per Novak's chart) is turning 2263.6 rpm at 75mph in 5th gear, with 4.56's and 33's you'd be looking at 2750.9 rpm at 75mph

agreed, that's why I suggested 4.56 and keeping it under 70 on the highway ;)
 
Negative Ghostrider, I ran a TruTrac for several years in my XJ D30 with NO steering issues!


If it worked for you cool, I had a D44 with disconnectable hubs so I don't know how it was with the trutrac up front on the street in 2wd. I know it killed my turning radius as soon as I put it in 4wd and locked the hubs though. Thats why I went ARB on the YJ.
 
agreed, that's why I suggested 4.56 and keeping it under 70 on the highway ;)

Sorry, but I like doing the speed limit (or 5 over) without thrashing on my engine. In the end its all a matter of driving style, personal preferance, and the area you live. If you mainly drive in town and up the mountains where the speed limits are less than 75mph anyways its different than if you regularly drive on I-25 fairly long distances.
 
agreed, that's why I suggested 4.56 and keeping it under 70 on the highway ;)

I'd love it if I could do that but on the other hand, my 35-45 minute drive to and from work everyday would take THAT much longer. Maybe when it turns into a trail only rig. :)

Sorry, but I like doing the speed limit (or 5 over) without thrashing on my engine. In the end its all a matter of driving style, personal preferance, and the area you live. If you mainly drive in town and up the mountains where the speed limits are less than 75mph anyways its different than if you regularly drive on I-25 fairly long distances.

Pretty much my setiments exactly Dutch. Oh, and I very much appreciate your input reguarding my issue. Thanks sir!

Edit: I actually appreciate everyone's input. It's really nice to be able to come here and ask dumb questions and not have everyone jump down your throat for it. :)
 
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If you truly want the best of both worlds, you'll want 4.10's in the axles and a 4:1 tcase, so you can comfortably crawl.
 
I'd love it if I could do that but on the other hand, my 35-45 minute drive to and from work everyday would take THAT much longer. Maybe when it turns into a trail only rig. :)



Pretty much my setiments exactly Dutch. Oh, and I very much appreciate your input reguarding my issue. Thanks sir!

Edit: I actually appreciate everyone's input. It's really nice to be able to come here and ask dumb questions and not have everyone jump down your throat for it. :)

No problem, thats what we're here for more or less.

Now if this was pirate you would've received a different response from me, I'm not such a sweet and joyful fellow on that site. I have to tone it down a bit here. :D
 
Do some more research before you get too excited. They are nice on the trail but you may not be too happy with the noise on the road.

Will do. Are they THAT noisey though? I mean, really noticable and can't hear your stereo? Either way, I need to do more research on it. It's just nice to have options that I'd never heard of or knew about before this, ya know? Thanks Frank.
 
From what I understand, and experianced with my TeraLow, is that they're only loud in low range. Mine whined like crazy in 4low, but didn't make any noise in either 4Hi or 2wd.
 
From what I understand, and experianced with my TeraLow, is that they're only loud in low range. Mine whined like crazy in 4low, but didn't make any noise in either 4Hi or 2wd.

Your TeraLow was performing correctly then. They are supposed to make a little noise in 4Low only. If a TeraLow setup is making noise in any selection other than 4Low than something is wrong! If you knew what was going on in that case while in 4Low you would have a bowl movement....lol. The coolest setup I have had a chance to operate is my brothers Toyota mini truck, he has duel cases, marlin crawler & 5.28's ......... talk about crazy low :wow:
 
A little noise? Made those ginat blowers on a funny car engine sound muted. :D

Toyota guys are rediculous in their crawl ratios. I've seen Yotas with like a 200:1 total crawl ration. With my crawl box setup and gearing I'm at 122:1 and thats rediculous as it is.

I used novak's miles per hour chart to calculate that in 1st gear with my tcase in low and the crawl box engaged (so lowest possible gearing) I'll be doing 3mph at 3000rpm. :D
 
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