Which atlas II?

[BornAgainXJer]

No!!!!!!!!!!!

Sounds great to me!


hinkley

That's what I was thinking

 

[Mike L]

That's what I was thinking

The 4.3 is the one I am gonna get as soon as the pocket book allows me to or I break something in the 231. Whichever comes first. I think the main concern with the 4.3 and an auto is whether the brakes are upgraded or not. I have heard of people with an auto, 4.88's, a 4.3 Atlas, and stock brakes not being able to stop while going downhill. The only way they can stop is to put the transmission into neutral.

-Mike

 

[korda]

Anyone have more input on gearing too low?

I was looking at a 3.8 or 4.3 atlas and someone brought up the point of being careful I wasn't so low the rig crawled through my brakes.

I've got 1/2 ton Ford brakes on my 44 front and the large GM calipers on the 60 rear. I've got a 4.0 with AW4, 4.56 gears in the axles on 35" tires, going to 36" next year. I'm running a corvette master with a wilwood adjustable prop. valve.

Thanks.

 

[BrettM]

Anyone have more input on gearing too low?

I was looking at a 3.8 or 4.3 atlas and someone brought up the point of being careful I wasn't so low the rig crawled through my brakes.

I've got 1/2 ton Ford brakes on my 44 front and the large GM calipers on the 60 rear. I've got a 4.0 with AW4, 4.56 gears in the axles on 35" tires, going to 36" next year. I'm running a corvette master with a wilwood adjustable prop. valve.

Thanks.

it sounds like you have plenty of braking power to handle either ratio.

However, the 4.3 (or even 3.8) may be too low for the type of wheeling you do. I have an AW4, 2.72 tcase, 4.88 diffs, 35" tires, and it's perfect for 99% of rock-crawling. If you do a lot of mud or wooded trails, you will likely find yourself geared too low with 3.8 or 4.3. They make a Highlander 3.0 case as well.

 

[What Rd]

IF all you do is rocks, particularly dry rocks, then low is the way to go. But as Brett said if you mix it up with wooded trails and muddy terrain you can easily gear yourself too low to be effective. Here in the muddy midwest, Rubicons are more handicapped than they are benefitted by their 4:1 t-case gearing (at least until they learn to run in higher transmission gears and really tach it up).
I currently run a 4.0, AW4 (with Brett's AW4 controller), 4.88s, 2.72 t-case and 33s. For the mix of wheeling I do, it's perfect. When I go a little taller, or start to get into big dry rocks more often, I'll want to go a little lower, but doubt I'd go as far as 4:1. I'm anxious to see what the numbers are going to be on the new 4-speed Atlas. Anyone know?

 

[BrettM]

IF all you do is rocks, particularly dry rocks, then low is the way to go. But as Brett said if you mix it up with wooded trails and muddy terrain you can easily gear yourself too low to be effective. Here in the muddy midwest, Rubicons are more handicapped than they are benefitted by their 4:1 t-case gearing (at least until they learn to run in higher transmission gears and really tach it up).
I currently run a 4.0, AW4 (with Brett's AW4 controller), 4.88s, 2.72 t-case and 33s. For the mix of wheeling I do, it's perfect. When I go a little taller, or start to get into big dry rocks more often, I'll want to go a little lower, but doubt I'd go as far as 4:1. I'm anxious to see what the numbers are going to be on the new 4-speed Atlas. Anyone know?

they're using np241 planetaries in front of their 3.8 Atlas, so you get 2.72, 3.8 and combined 10.*

 

[woody]

they're using np241 planetaries in front of their 3.8 Atlas, so you get 2.72, 3.8 and combined 10.*

I've been reading up on that, seems like the ticket for a medium WB rig.

Just for fun: a 5 spd XJ's crawl ratio is like 31:1 (low range/1st gear)

add bigger axles, NV4500, Atlas IV: 5.4 axle gear x 5.6 1st gear x (2.7 x 3.8 case gears) = 30:1 in hi-range/1st gear, 82:1 with the 2.7 engaged, 114.1 with the 3.8 engaged, 312:1 with both case sets engaged.

Skip the granny-gear tranny/keep the AX15: 20:1, 56:1 with 2.72, 76:1 with 3.8, and 206:1 with both lows.

 

[043500]

Supposedly once the atlas 4spd hits the market the 2spds are supposed to drop in price by quite a bit and the 4spds are supposed to comparably priced with the STAK 3 spd cases. THis is in a couple of the magazine articles I;ve read....not that I believe everything in magazines...BUT it makes sense.

 

[korda]

I guess I haven't had the same experiences that some of you guys have had. We do plenty of trailriding on wet, loose and very tight trails. The rigs I wheel with that have a 4:1 have that much more control in every situation. I woudn't describe any of them as handicapped.

Thanks for the input. I wish I had the cash to buy one of those new multi speed cases but I'm really stretching it as it is.