Atlas II Specs and opinions

[Buckshot]

This was originally going to be a PM for Jefe, but since Kevin and Ray could answer as well, and it might clear up these questions once and for all - I am making it a regular thread.

Can anyone (Ray, Jefe, Kevin) post the correct specs for an Atlas II and your current opinion on 4.3:1 vs 3.8:1 Atlas II? I have an 97 OHV with the Auto tranny and a blown 4405. And I haven't regeared the rear just yet either....so I could go 4.56 and Atlas 4.3 or 4.88 and Atlas 3.8, or even some other combo (I'm 3.73 on 35" tires right now ).....just don't know yet.

Probably need to get the Atlas ordered ASAP to get it in by June so I'm hoping someone can help with some shortcuts on the research. And your opinions now since I have read many posts about 4.3 would be bad for stock brakes, 3.8 is a little rough for Jefe in reverse, and this of course is muddled by differential ratios too...

I have $4k to drop on regearing, e-locker, an Atlas and new driveshafts if need be. (I know I'll at least need to replace my front driveshaft since I have that odd spherical flange connection.)

 

[Ray Lobato]

You're gonna have to replace both driveshafts, because the Atlas is alot bigger that the stock Transfercase. They cut the length from the rear driveshaft on mine, but I don't remember by how much.
My Atlas is the 3.78:1 ratio and I am running 4.10 gears. You will have to get a speedometer adaptor from Nevada speedometer (the address is in the manual) to adapt to the jeep speedo gear inside of the transfercase.
The only problem I had was when I first got it, after wheeling for a day, my transfercase wouldn't stay in 4lo on the front, but that was just an adjustment of the linkage. Make sure that you put a little locktite on the nuts to keep them from vibrating loose. I have no complaints.
What kind of specs are you looking for? I guess I'll look for the manual when I get home.
Oh you also have to tell them what kind of yoke on the front and back outputs of the transfercase that your want.
Hope this helps.

 

[Buckshot]

I guess I need to do some more reading. I'm not sure what yokes I want, nor specs for the driveshafts. What did you do? I guess I'm looking for as much info on length of driveshafts and yokes and everything so I can just order all the right stuff and install it in one weekend without having to put in the Atlas, then measure what I need for driveshafts, then yank the Atlas and put the 4405 back in while waiting for driveshafts....I don't want much

On the choices for the Atlas - 3.8 vs 4.3
I've been told that I need 4.88s for my 35s, but I'm also hearing that a 4.3 Atlas would allow me to stay closer to the stock ratios in high at 4.56 in the diffs and still give me similar crawl as 3.8 and 4.88.

Also - I'm looking for real-world pros and cons for the Atlas case. I here all positives on this site and it sounds great. But there have to be some negatives that you know about now that you've had it in for a while.....right?

 

[Doug]

If you're going to order an atlas order it now, I've been waiting almost 2 months now for my 5:1. There are no negatives about the atlas, except the price.

 

[Jefe]

specs as in what?

If I were to do it again, I would get the 4.3:1, even with the 4.88's. Even then I'd probably still dream about adding a klune inline. On flat ground I have no problem keeping the rig from rolling while in gear. On extreme inclines, yes it will overpower the brakes, and then you either have to rely on engine braking (another reason to go lower) or pop it in neutral. The only times it has been dangerous are when I'm going up an obstacle and need to back down, and thrown it straight into reverse. I now hit N first until I need power to get rolling.

Now that I have the 3.07:1 1st gear of the 700R4 it is better, but I STILL wish it was a bit lower. But now I CAN put a Klune inline.

 

[Buckshot]

sorry - lengths and such - I remember reading a post about someone (maybe Jefe?) popping in the Atlas and then measuring needed driveshaft lengths and then popping the 4405 back in. Which is what I want to avoid. (it's my daily driver, so I have a weekend to complete it)

 

[Jefe]

sorry - lengths and such - I remember reading a post about someone (maybe Jefe?) popping in the Atlas and then measuring needed driveshaft lengths and then popping the 4405 back in. Which is what I want to avoid. (it's my daily driver, so I have a weekend to complete it)

Yup, that was me. And it was the weekend before a Moab trip and I had to take it back out because I couldn't get driveshafts in time.

I can give you my measured driveshaft length, but there is no guarantee that it is correct for you, and I'd hate for you to have a driveshaft made the wrong length because of it.

 

[bmxking5]

If I were to do it again, I would get the 4.3:1, even with the 4.88's. Even then I'd probably still dream about adding a klune inline. On flat ground I have no problem keeping the rig from rolling while in gear. On extreme inclines, yes it will overpower the brakes, and then you either have to rely on engine braking (another reason to go lower) or pop it in neutral. The only times it has been dangerous are when I'm going up an obstacle and need to back down, and thrown it straight into reverse. I now hit N first until I need power to get rolling.

Now that I have the 3.07:1 1st gear of the 700R4 it is better, but I STILL wish it was a bit lower. But now I CAN put a Klune inline.

Jefe, you can always just sell me your Atlas and get a 4.3:1. It would be just slightly better than getting a manual 1354, but only by a little. Like Doug said, the only con about an Atlas that I know of is the price.

 

[Diff Whack Daddy]

specs as in what?

If I were to do it again, I would get the 4.3:1, even with the 4.88's. Even then I'd probably still dream about adding a klune inline. On flat ground I have no problem keeping the rig from rolling while in gear. On extreme inclines, yes it will overpower the brakes, and then you either have to rely on engine braking (another reason to go lower) or pop it in neutral. The only times it has been dangerous are when I'm going up an obstacle and need to back down, and thrown it straight into reverse. I now hit N first until I need power to get rolling.

Now that I have the 3.07:1 1st gear of the 700R4 it is better, but I STILL wish it was a bit lower. But now I CAN put a Klune inline.

What he said. I have to agree whole heartedly on the 4.3:1 if I did it again. I haven't had a problem overpowering my brakes yet as Jefe explained, but that could be a number of reasons.

Jefe, don't want to steel the thread, but didn't you have the Atlas before the 700? If so, isn't your Atlas the funky Ford 5 bolt with the 25 spline input just like mine? If it is, then we are still in the same boat with the Klune, it won't work. Before I did the 700 swap, I was slated to be the R&D vehicle for the Klune, but the engineer who was backing me left Klune and opened High Impact.

 

[Buckshot]

Ok - all the parts are in. 4.3:1 Atlas II, Driveilne e-brake from High-Angle Driveline, twin stick shifter with cable attachment instead of hard mount (so I can fab up a bracket for it in the middle of my console ABOVE my rear air without cutting into the ductwork!). 4.88 Yukon's for front and rear and an EATON e-locker. My wife is ready to kill me and take the checkbook away! Everything is finally going in July 11th.

Last question (yeah RIGHT!). I've seen some things that say that the speedo gear conversion unit from Nevada Speedo is REQUIRED for the tranny to shift. Do I now need to wait on that thing too? Or can I just put that in later to make my speedometer work again?

 

[Jefe]

Last question (yeah RIGHT!). I've seen some things that say that the speedo gear conversion unit from Nevada Speedo is REQUIRED for the tranny to shift. Do I now need to wait on that thing too? Or can I just put that in later to make my speedometer work again?

Your trans will not shift very well without a speedo though it will work, and unfortunatly with a 97 you have no choice but to get an adapter from Nevada Speedo.

 

[gmanpaint]

Your trans will not shift very well without a speedo though it will work, and unfortunatly with a 97 you have no choice but to get an adapter from Nevada Speedo.

Old thread, but just found it.

So for those that did this in the 2nd gens, I am unsure about the VSS setup. AA gives the proper gear, but that's all I know. They said they use the Dana 300 speedo assembly in them, but do not include it. So from what I can tell, they send you the case with a speedo hole in it. They say to have Nevada speedo make a signal converter, but do not say what else I need to make that work. Nevada speedo asked if they include the cable tube. I said all I know is they send the speedo gear for my ratios.
I just don't know exactly what all I have to do to get the VSS working. They sent me this pic saying this is what the case uses, but it is not included. The sales dept is not being very forthcoming to what all they send & what I need.

I'm about to be in the same boat as Jeffe was with getting this installed in time for an upcoming meet. I will have a few days to install it, and be ready to hit the road, and am attempting to get my ducks in a row. Any help with info on what I need to get, is appreciated.