All --

I saw this on Ebay and was wondering what the benefits would be of putting this in my 75 Bronco. Atlas 2 Speed Transfer Case -- Item number: 290686173577.

Thoughts?

I know at least one guy, JD has one in his truck. I aim to have one someday, but can't afford one yet. There are 2 options for low gear, something around 3.5? and 4?, so you get a lower 4 low, twin stick, and they are super strong. Overkill unless you are really going to abuse your truck. I think they are longer than the stock D20, so you may need to mod your driveshaft, and you'll need an adapter to mate it to the stock trans. You might need a body lift to get it to fit without major cutting.

I'll let someone who has one tell you more.

http://www.ebay.com/itm/Advance-Adapter ... 89&vxp=mtr

It would need a 28 spline input shaft and maybe a different clocking ring to work in a Bronco. Driveshaft mods would be required. Benefits are they're very strong and this one has a 5:1 low gear. Your D20 has 2.34:1 low gear. Great for crawling but limits your speed in low range to a max of about 20 mph.

Ok, so I am guessing that while it would be great, it is probably way beyone my wheeling needs / budget. With everything out of the Bronco right now, all kinds of ideas are crossing my mind before I dump the engine and trans back into the vehicle. :-)

Mine is actually a 4spd, so it has the planetary along with the main gear box behind. IMO the single best place to get crawler gears is in the t-case. That way you have your low gears for the crawling and maintain your highway gearing.

This is a good case. Depending on your tranny, you will need an adapter there. Do you have an auto or standard? I don't know that this Atlas is any longer than your D-20, but with adapters, it could be. There are dimensions on AA's website.

Before I got serious about this one, I'd get quotes from other suppliers. I can give you a contact for mine. I actually got my 4spd for cheaper than they are listing the MSRP for on this one.

Plug your numbers into one of the online gear calculators and see what the differences are with your current setup vs one with the 5.0 Atlas
http://www.rocky-road.com/calculator.html

Finally, the Atlas has been one of the best mods I have done to my bronco. I got the clock-flat version, so I do not have anything that hangs below my frame rails under the belly. But that takes frame and floor pan modifications. Still well worth it as I used to get hung up so much on my D20. Not to mention the control you get from going slow.

Have any specific questions? I wonder why they took it out of the XJ to start with?

JD, I know you'll be headed out of the country before I'm ready to upgrade to an Atlas, but if you could post or pm me your supplier and pics of your install mods, I'd love to see it. Do you have a body lift in addition to the frame/floor mods?

Sure! My pics:
http://s8.photobucket.com/albums/a39/je ... 20Install/ - also a write-up here: http://www.colorado4x4.org/vbb/showthre ... ight=Atlas

If I were to do it again with frame mods, I'd weld in a piece of 1/2" plate inside the frame as opposed to doing what I did outside. Just because it makes the frame non-symmetrical if I were to build something in that area. I may also lay in some 1/4" plates top and bottom inside the frame as well. Aside from that, I am completely happy!

I have a 2" body lift and you can see how much the floor was modified.

I bought my Atlas from Kincade Bauer rawkdog@gmail.com Best price I could find. (I appreciate you telling him who sent ya)

Word of caution - It took 6 months for me to get my Atlas. Based on what I have seen on another build thread, they are still behind, but maybe not that much.

J.D.

Thanks JD,

I've bookmarked these pages, and hopefully will get to use them someday. This is the first build thread & pic set I looked at and didn't realize how much work it was to install one of these. It looks like the extra work to clock it flat is significant. I've accepted that I'll be doing a body lift, but 2" was more than I wanted. Looks like you need the 2" to do it flat. I've got more to think about now. Do you think it could be installed, with no bl or a 1" bl, if you leave it hang below the frame? I know why you want it above the frame, but I still use the truck to haul my dogs, and adding more lift will make it difficult for them to get in. And I can't lift a 115# lab or a 125# Pyrenees in/out of my truck. I recently measured my axle to frame, and realized my 3.5" lift has settled down to about a 1" lift. So just installing my new springs will be lifting my truck a lot, adding a bl is going to put it in the sky.

Chad

Chad, It was a lot of work, but for a dedicated wheeling rig like mine, it was worth it. I think you'd have to do a 3" to avoid body work on the clock flat. I do believe that a normal version of the T-case will install without a BL, or maybe a small one. I know others have done it. I was one of the first IIRC, and probably the first with the Clock-flat. Anyway, the normal version shouldn't hang below the frame anymore than your D20, but you'll want to protect your investment with a skid that can hold up the entire weight of the bronco. They are awesome cases, but come at a price!

I understand completely with the dogs. My 125# Chessy is too old to jump in anymore, so guess who gets to lift him...

Chad this is the option I was lookin at.

http://www.northwestfab.com/blackbox-i.html

Zoso,

I saw that when it came up on the cb.com site, I'm still keeping all options open. My concern with the black box, was shortening the rear driveshaft & the potential severe rear drive shaft angles. I don't expect to get a 4 speed like JD, just the regular 2 speed Atlas. I like the black box & Atlas because it keeps the low gears in the t-case, while keeping the high gears in the axles, seems like the right solution, like JD said. Both the black box & the Atlas give you low gears on the trails and high gears on the road, the best of both worlds.

I thought my D20 was shot, but I twin sticked it and it cured the popping out of gear, so I've got more time to think & save $ for an option. We'll see what happens. When I considered the cost of upgrading & rebuilding the D20, the Atlas seemed like a good one-shot solution. I'd like to upgrade to an automatic trans, and since the Atlas bolts to the 4R70W with no adapter, it seems like a good option. These are all very long term ideas, nothing will happen in the next year, or maybe more. Maybe by then I'll have a tow/hunting/dog hauling rig, and driving down the highway for long runs will not be a concern. Only time & money will tell.