YJ flat belly with Atlas?

1993yj

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Location
Salt Lake
I have decided that I need some lowering gearing, which makes for a good excuse to do an Atlas. Looking to replace the 231 with a 4.3 two speed. Currently I have the 231 clocked so I have a completely flat belly with no body lift and not cutting into the floor. I did have to do a 1" motor mount lift. I know that the cases are about the same in height, but has anyone fit an Atlas this way? I won't do a body lift, and will cut into the floor if needs be (hoping I won't have to), but trying to figure out what will be necessary before the project begins. It will be a winter project.
 
It's way too early to be thinking about this, so my peoples that probably have a few more brain cells that aren't exhausted can help you out on this. That being said, I will give my personal experience regarding this.

I too replaced my 231 with an Atlas 4.3. I have a 1" motor mount lift, had a 2" inch body lift, and an almost flat belly pan. I took the 2 " body lift out and with the tranny tunnel being narrow on the YJ, it squeezed all my shift levers into a very small space. I did end up cutting the floor more than I wanted to, but it was the only way I could get the Atlas levers to work full range. I believe that after doing this, I read somewhere that Advance Adapters either recommends a spacer to drop the belly pan down a little or a 1" body lift to accomodate the components. I also noted that without the body lift, I get a bunch of grinding/popping from the t-case against the tunnel as well that I didn't get before removing the lift.

I think sometime this winter, I will be dropping my belly pan down a bit. Just in the last two years I was able to start parking in my garage even with 40" tires. I don't want to lose that by putting a lift back on. Sorry for the rambling, hope this made sense and helps with your thought process...
 

1993yj

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Location
Salt Lake
Thanks. That's exactly the kind of info I was looking for. My other option is always to just do the Tera 4:1 kit for the 231 because that way I will be able to keep everything where it is currently, but I can't confirm that it will work with a clocking ring. Tera told me they think it should, but said that their long input shaft is only 1.75" long from the face. That is already ~.35" shorter than my stock input shaft, and when you add in the 3/8" spacing for the clocking ring, I am not sure that it would work. I also figure that doing the Tera kit would get me by for a while, but ultimately I would want an Atlas in the long run.
 

skippy

Pretend Fabricator
Location
Tooele
I run an atlas clocked flat in my wifes TJ with the belly up skid plate from teraflex and the atlas is about an 1/8" away from just about everything with a 1" body lift. I say skip to the atlas but if you want a teralow Shoot mesha a message and he can get you a smoking deal on a new one often times cheaper than you can find a used one
 

skippy

Pretend Fabricator
Location
Tooele
depending on how your lower links are mounted on your frame I would want the belly pan low enough so its a smooth transition onto the lower links. Yes its lower but having the smooth transition keeps you from getting hung up on your link mounts.
 

1993yj

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Location
Salt Lake
If/when I go Atlas the clocking ring and 231 (with SYE and Novak cable shifter) will be up for sale. It never was a question of what do I want to go with, but rather how well will it fit into my current setup. Pretty sure that's still the route I will go, I will just be prepared to lower my skid plate a bit.
 

STAG

Well-Known Member
If you decide to cut your floor and need help with welding in the new sheet metal let me know.
 
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