I am currently running the terraflex terra low 4:1 in a 231 with an sye and extra large hd chain kit. I’ve got 5.13 gears in the axles as well. No problem with it. But I want to upgrade before there is. I’ve gone larger tires etc. since installing. and also want the ability to have 2 low and just front dig etc. my questions are if I order the one for the current ax-15 and swap to the 32RH auto in the future as is the plan can I use the same transfer case without issue. Or should I do the auto swap first? Second is anyone using the atlas in there Tj. I’m leaning toward the cable shift set up to make install easier as well as smoother shifting. With the stock engine and trans. Is it worth the upgrade to the hardened output shafts. Does the 4.0produce enough power and torque to warrant the cost? Leaning towards the 4.3:1 unless I go 4 speed then I am leaning toward the 8.? Final low gearing box. Any thoughts or ideas/ help from people that have one or have researched it. I just started looking at them today as I saved a bunch on my hydro assist steering kit by finding a nearly new used set up and this was next on the list.
Had a similar setup to what you currently have. 4.0/NV3550/Teralow 4:1/4.88's. Last January at the Winter 4x4 Jamboree in St. George, UT i smoked the planetary thrust washers. Teraflex no longer has parts for the Teralow, so the rest of the 231 became a parts donor to a friend who also runs a Teralow. If yours still runs, you should be able to sell it for a decent amount. I had multiple people asking if I was selling it until they found out it was smoked.
I talked with Mike Partridge at EJS, and told me a lot of the same things they told you on the phone. (Linkage shifters, 4.3 ratio, 1310 u-joints, etc.) I ordered a Trail Series T-Case in late April and got it late June.
Regarding the AX-15 swap to 32RH, the biggest deal you'd run into is if you had to swap input gears. Not a huge deal either way, I personally wouldn't wait to swap an atlas in until the trans swap is done.
Cable vs. Linkage- I like the look of the shifter setup better with the cable shifters with the knobs side by side and the actual shift pattern. The cable and linkage shifters shift pattern are reversed from each other. Since they recommended the linkage shifters to me, I went with those. They do fit nicely in the stock location in the console. I'm happy with the linkage.
Hardend output shafts- I don't remember seeing an option for hardened shafts when I ordered. I went with the Trail Series case, I assume that means that they are not the hardened units.
I stuck with the 2-speed because of price and DS lengths. I asked them about 5.0 vs 4.3 and they told me 4.3. I can see where the 5.0 can come in handy, but wouldn't have changed anything if the Teralow didn't go on the spazz. For the type of wheeling I do, I am happy with the 4.3.
It took me 1 day to install the Atlas at a leisurely pace. Probably could have been done faster, but didn't want to rush. FWIW, I really like the sight tube feature, its worth the extra few pennies to get it.
