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81

The Mess Hall / Re: Which Atlas Transfer Case

« Last post by Jeffy on August 21, 2020, 09:05:35 PM »

Well personally I loved my 2:46 and 4:1 combo But I think a 2.7 and 4:1 would be perfect!
The 4 speed Atlas should fit the bill just about right. Or a Black Box i and a flipped 300 with 4:1.
Or a 4:3 Atlas then if you feel you need more choices add a Black Box to it. You can do that down the road. Granted you would have driveshaft mods. I sent mine out to be modified vs buying new ones. Much cheaper.
Granted I mostly just ran the 4:1 it did just about everything I wanted with 5:38's on 35's. But I feel the 5:1 would be to low for most trails.

I just tried out my Black Box a couple weeks ago. Im not 140:1 vs 208:1 with the Klune. I do enjoy the 2:7 the 2:46 is not low enough for my tastes.
I ran it in all figurations to see what's what. Having both in low I used 3rd gear on the transmission mostly for the trail I was on. I did use first gear low, low and it was ok. Not near as low as I was before. But it should be plenty for what I do.

Hitting the Dusy next week. I'm sure I will use all the combinations. Where as before I would just use the 4:1. After I switch from 4:88's to 5:38's I pretty much would only use the 4:1 unless it was a very mild part of the trail.

So that puts you at 84:1 with just the 4:1.  That seems to be the golden number for the Rubicon.  The TJ Rubicon who was with me was pretty much stock on the same tires and was 65:1 but I know that's not going to be low enough for a 2.5L.  An AX-5 and a 4.3 would already be 86:1.

I'm curious to know how much you use 2nd and 3rd with any combination though...  I just realized you're running 2.46 and 2.72 not 2.46 and 4:1.  That's huge overlap then.  So really you're only using or 2.72 or both.

I'd kinda like to keep it simple so that's why I'm consider a 2-speed over a 4-speed.  I'm sure if I ever do an engine swap 5:1 will be too low...  Gonna have to look at all the numbers again

82

The Mess Hall / Re: Which Atlas Transfer Case

« Last post by FourbangerYJ on August 21, 2020, 07:45:14 PM »

Well personally I loved my 2:46 and 4:1 combo But I think a 2.7 and 4:1 would be perfect!
The 4 speed Atlas should fit the bill just about right. Or a Black Box i and a flipped 300 with 4:1.
Or a 4:3 Atlas then if you feel you need more choices add a Black Box to it. You can do that down the road. Granted you would have driveshaft mods. I sent mine out to be modified vs buying new ones. Much cheaper.
Granted I mostly just ran the 4:1 it did just about everything I wanted with 5:38's on 35's. But I feel the 5:1 would be to low for most trails.

I just tried out my Black Box a couple weeks ago. Im not 140:1 vs 208:1 with the Klune. I do enjoy the 2:7 the 2:46 is not low enough for my tastes.
I ran it in all figurations to see what's what. Having both in low I used 3rd gear on the transmission mostly for the trail I was on. I did use first gear low, low and it was ok. Not near as low as I was before. But it should be plenty for what I do.

Hitting the Dusy next week. I'm sure I will use all the combinations. Where as before I would just use the 4:1. After I switch from 4:88's to 5:38's I pretty much would only use the 4:1 unless it was a very mild part of the trail.

83

The Mess Hall / Re: Which Atlas Transfer Case

« Last post by Jeffy on August 16, 2020, 06:42:59 PM »

Well, I talked to SST who with Tremec packaged the TR4050 and they said they didn't have an application for the 2.5L/GM 60* bolt pattern.  Sucks but I wasn't expecting to see one as the GM 60* family gets overlooked for the 90* pattern.  Would have been nice to shed 40# and had a lower 1st.  But that's a lot of money to spend for a nche group.

The downside to the NV4500 is that it's been out of production for more then 10 years but then I don't think it's ever going to be an issue with a 2.5L  It's wat overkill.  Some things to consider is that the conversion on an older YJ adds 1" to the drivetrain length.  IIRC, the Atlas 4 is 2" longer than the 231 but is fine for the front shaft.  An Atlas 2 would give me a longer rear shaft, I'm at 19" now, and shorten the front which isn't an issue.  What I'm wondering though is 11.70 too low to be useful?  1st is a stupid 336:1 in the NV4500 and 2nd is 3.06:1 so that gives you 204:1 and 3rd is 1.67:1 giving you 100:1.  I'm kinda thinking that might be too low to be useful.  If I keep the AX-5 it's a lot more useful though as 1st is 3.92.  Going with a NV4500 basically acts like a doubler.  Going with a 10.34:1 Atlas 4 and 2nd gear would be 162:1 already.  So basically what 1st and a 5:1 would give.

I'm kinda leaning towards the 5:1 at this point.

84

The Mess Hall / Re: Which Atlas Transfer Case

« Last post by Jeffy on August 13, 2020, 12:29:05 PM »

I guess if your main fun will be on the rocks, the Atlas or the oem rocktrac would help.
I think I remember you’re running 4.56’s, I run 4.88’s and 33’s, and your right,
a lot of clutch work on the Rubicon with the stock 2.72 case.
I find with the 4 banger, I typically am the first to shift into low range in my club,
and the 2.72 for the most part does the job.
I debated about getting a 4.1 kit for my 231, but didn’t want to live with it all the time.

Currently my axles are 4.56 but I'm planning on 5.13's so it's more driveable on the street.

Looking at the numbers. if you had 4:1 and shifted into 2nd, you'd have 42:1(2.33x4x3.45) vs 49:1(3.92x2.73x4.56).  Really you need to calculate all of the gears (minus OD) to see that the spread is like.

Problem with the Teralow is that it's noise and prone to breaking.  I don't think you can get a RockTrac to bolt up to an AX-5.  I haven't been able to find out if you can swap the input shaft or not.  My assumption is yes, since a lot of NP2xx parts are interchangeable but for the price of a 231OR, I could get a Atlas 2 and have twin stick, a shorter case and gears rather than a chain.  I've had a few times where 2Low has come in handy.

So for me, really it's the Atlas 2 5:1 or the Atlas 4 11.70.  The only downside to the Atlas 4 is the gearing gets really low with compound gearing.  If I keep the 2.5L though that shouldn't really be a problem. Thee downside to the 5.1 is fewer ratios and limiting the top end to 143:1.  Though that's a nice ratio for the Rubicon from what I've heard and have experienced.

I'm also looking into if you can mate a TR4050 to the 2.5L.  That should be a better transmission than the NV4500 as it weighs 40lbs lighter and has a lower 1zt at 6.16:1 and 2nd at 3.11:1.  With a Atlas 5:1, 2nd gear should give me the equivalent of a 4:1 and 3rd would give me what amount to 2.72:1.

85

The Mess Hall / Re: Which Atlas Transfer Case

« Last post by 95 Lowbuck on August 12, 2020, 07:22:11 PM »

I guess if your main fun will be on the rocks, the Atlas or the oem rocktrac would help.
I think I remember you’re running 4.56’s, I run 4.88’s and 33’s, and your right,
a lot of clutch work on the Rubicon with the stock 2.72 case.
I find with the 4 banger, I typically am the first to shift into low range in my club,
and the 2.72 for the most part does the job.
I debated about getting a 4.1 kit for my 231, but didn’t want to live with it all the time.

86

The Mess Hall / Re: Anyone still have the old Ebay YJ turbo e-book?

« Last post by Jeffy on August 08, 2020, 07:24:49 PM »

I remember the pdf being comical at best.

87

The Mess Hall / Which Atlas Transfer Case

« Last post by Jeffy on August 08, 2020, 07:22:47 PM »

So, I've been thinking about this again.  The first thing I should mention is that I want to replace my AX-5 for an NV4500.  I'm thinking Atlas 2 (5:1) or Atlas 4.  Problem is which ratio should I go with.  The easy answer is the lowest available.  That would be 11.70:1.  Although with the NV4500, 8.16 might be a good choice.  That's 2.72:1 and 3.0:1.  The argument being that the ratios basically overlap each other.  With 11.7:1 though you could shift into 2nd and have 182.5:1..  I know a few members have compound low transfer case gears.  Think 11.7 would be two low?  I know Taco guy's stack Marlin crawlers.  I think the lowest I've seen is 580:1 on an employee's rig.  I'm currently only running 33's and don't really have plans on going larger.  The toughest trail I've done so far is the Rubicon and 2.72 just doesn't cut it.  I don't think 4:1 would either with the 2.5L.  Something in the low 100's would be optimal and anything above that is gravy.  So realistically, 5:1 would work.  143:1 (1st)/77:1 (2nd)/43:1  (3rd)

AX-5 x 5 x 5.13 = 101
NV4500 x 5 x 5.13 = 143
AX-5 x 8.16 x 5.13 = 164.9
AX-5 x 10.34 x 5.13 = 208.9
NV4500 x 8.16 x 5.13 = 234.8
AX-5 x 11.7 x 5.13 = 236
NV4500 x 10.34 x 5.13 = 297.6
NV4500 x 11.7 x 5.13 = 336

88

The Mess Hall / Re: *** Introduce yourself here! ***

« Last post by Long_Nose on August 05, 2020, 09:44:07 PM »

Hi everyone. I finally got an account after figuring out the process. I'm on the Facebook one. But there's more stuff on here I guess. The vehicles info is as follows: 1997 2.5 auto 2.5l red with 31x10.5 tires; almost all stock with 170 k. Needs a lot of work now what she runs and passed smog after sitting for a couple years because of electrical issues and lost keys; it's been in the family for 22 years (1999). Slowly fixing it up; got it to drive reliably since last year but it's gas mileage sucks. With 170k and a slipping transmission that has hard time going to reverse unless it's warmed up and hot outside or driving on the freeway for an extended period. Yeah I could use the help and advice that others have. I've been  reading about Jeeps for awhile and I can replace an alternator, starter but I've never taken apart an engine on the internal side except years ago in automotive class back in the 90s. Anyway I just wanted to introduce myself/old redena (name jeep) sorry for rambling on. 1 Jeep wave to another hi.

89

The Mess Hall / Re: Custom digital gauges with OLED and Arduino

« Last post by IRQ on July 27, 2020, 11:26:40 PM »

Just an idea :)

https://intellitronixgauges.com/1992-1995-jeep-yj-led-digital-gauge-panel/

90

The Mess Hall / Re: *** Introduce yourself here! ***

« Last post by MJ4BangRocker on July 25, 2020, 10:02:29 PM »

Just joined, just joined the 4 cylinder world in total. Picked up an 86 MJ this past Friday, TBI 2.5 5 speed w/ 4wd. Factory 4.10s i think. Long bed It's got a 3 link up front and bigger leafs out back on 33s, so i'll be using it for weekend trips and for puttin around town. Can't do anything else, barely get's outta it's own way.

I'd like to slowly fix it up and restore it a little as they are slowly getting harder to find, but definitely wanna give the abused 2.5 some of it's life back.