Full Size Jeep Network

Anyone out there running an atlas behind the TF727? I have some questions about some things for. Tried to do a search and couldn’t come up with much.

An atlas is easy to install behind a 727. Plenty of people have done it. Did you have a specific question?

I am, running the 4spd version. I'll answer any questions I can.

Just wondering what ratio you went with and what your setup is. Motor, axles, ratio and tire size? How was the packaging. What was the change on drive shaft lengths?

My sig has most of the info. I went with 37" tires and 4.56 gears. With a non-OD transmission this works out okay on the highway but isn't deep enough for off road. That's why I went with the 4 speed. I picked up mine used but never installed. The main transfer case is 2.0. The auxiliary planetary gear is always 2.72. So I have the option of 1 to 1, 2 to 1, 2.72 to 1 or 5.44 to 1. 5.44 to 1 is plenty deep for technical stuff.

I had to replace the input shaft because the used case I bought was set up for a Nissan. It' was pretty easy to swap out the input shaft.

With the addition of the planetary gear the case sits a bit further back compared to a stock np208. So the rear shaft was shortened and the front shaft was lengthened.

I had to trim the 'coffin' for the fuel tank a bit.

I am having issues with the planetary gear popping out when engaged in low. I believe this is an adjustment issue and when I get a chance will drop the case and take a look.

I mostly drive around the trails in 2.0 and often just with the rear wheels.

Wish my JK had a three speed case. The 4:1 is awesome for crawling, but sucks for most trail cruising. But high range is often too high and results in increased trans temps.

Stuka wrote: ↑Mon Jan 13, 2020 1:25 pm Wish my JK had a three speed case. The 4:1 is awesome for crawling, but sucks for most trail cruising. But high range is often too high and results in increased trans temps.

Even with the OD transmission? I would think that would help some. But I agree that 4 to 1 is too low for trail cruising. My 2.0 is about perfect for shelf roads and non technical stuff. And it's a blast running sandy washes in 2.0 rear wheel only. I can whip it up to 30 or 35 mph in no time.

The JK's have such a low first gear in their transmissions the stock transfer case should suffice for most people.

Thanks guys took me a while to reply. I am currently on 40’s and have 5.13 gears. But stock drivetrain. The lack of crawl ratio is destroying the body. I feel like I may hold out until I have the funds for a 4speed. That would be ideal. I like my 5.13’s for the street but dang is it tough in the rocks. I also don’t want to end up too low however.

I watched on Pirate and a deal came up. I was lucky, it was 'used' but never filled with oil or installed. I got a pretty darn good deal on it. Patience is the key.

I plan on adding a Black Box reduction case to my FSJ. It is significantly cheaper, 2.72:1, plus the 2nd/OEM case 2.72:1 that allows 1:1/2.72:1/554:1 and allows for a longer front drive shaft [less angle]. https://www.northwestfab.com/NWF-BlackB ... e_c_7.html