Transfer case gearing question

lomodyj

lomodyj

Well-Known Member
Joined
Mar 21, 2005
Location
Out in the Middle
Looking at purchasing an Atlas II to replace the NP231 in the YJ. Not finding a lot of info on best gearing in the case... YJ has the 4.2L 6cyl (MPI) and the TF999, Axles will have 4.88 gears running 35 inch tires. Atlas is offered in 3.0, 3.8 and 4.3:1

Jeep is used mostly for trails, some rock crawling and as little mud as possible...

Thoughts? Opinions?
 
It depends on the wheeling you will want to really do. All three will be a upgrade to what you have now. From my experience, Rubicons with the 4:1 are very impressive in rocks where slow crawling is preferred. You need to decide what will work for your style of wheeling. Thinking stock 231 is like 2.7:1. Enjoy shopping!
 
A friend of mine is running the 3.8:1 case in a 4.0L, 5 speed TJ with 4.56's and 35s. He is geared very well for crawling and all around wheeling, IMO. I'd say go deep, but with the auto tranny, it's not as necessary. I wouldn't go for the 3.0:1. Either of the other two options will work out great for you. Your next issue, though, will be braking. With all that low gearing, your booster just isn't gonna cut it on anything downhill. You're gonna have a helluva time stopping that thing without popping it in neutral.
 
Galen,
I think with the mix of trail riding/crawling you do I would consider either the 3.8 or the 3.0. I would lean towaards the 3.8 for the simple fact that even though I find my 4:1 a little slow for straight trail riding you can always pop it in high for the easier sections. I never find it too low for crawling rougher sections, but my final gearing is not quite as low (4.56's, no auto advantage).
 
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