231J HD Upgrade

Since doing my 5.3L/4L60e swap a transfer case upgrade has been on my mind. It says on the Novak site that the NP231 is “well mated to V8 power”, but I know that 5.13 gears, 35” tires and difficult terrain can make that statement questionable.

I read on just about every Jeep forum that all you have to do is find a 231C for 50 bucks on Craig’s List to get the wide chain and gears, and then find a 241D HD and grab the 6 planetary gear-set. Well, I looked most every day for about 6 months. I never saw a 231C for less than $150 and I never saw a 241D HD at all. I thought I was just going to have to run my 231J until it broke then go up to a 241OR or even a Altas when the time came.

Somehow I came across a guy on Ebay that was selling the t-case parts and I contacted him. http://stores.ebay.com/powertrain-p...=5303410&_sid=369570213&_trksid=p4634.c0.m322
He said he would sell me a slightly used, but good condition wide chain and gears, plus a 6 planetary gear-set for $142 shipped. I was surprised and didn’t think it could really be true. I wasn’t having any luck with my original plan so I decided to take a gamble and try it. The parts arrived quickly and were indeed in good condition.


The only thing I have ever done to a t-case is installing a couple SYE kits. But, I have done a couple manual transmissions so I figured it couldn’t be worse than that and yanked my t-case out and started to disassemble it.

Tail cone off.


Back half of case off.


Pulled this out of t-case.


231J three planetary gear-set.


Remove front cover.

Re: 231J HD Transfer Case Upgrades

Pull the input gear and planetary out.


Reassemble input gear with new six planetary gear-set.


Here is the difference in the size of the chains.


Difference in the gears.


Pop this thing off the output gear.


And this.


So it looks like this.


241 gear on the right has roller bearing inside you need to knock out.


Put it back together,


That’s it! Reinstall the t-case and enjoy your new found piece of mind.

It took me a total of about 3 hours because I was taking the pics and trying to remember the steps.

Why is the magnet on the end of the shifting shaft? Hope you don't forget to put it in the right place before things go on.

I didn't. I just set it there so I wouldn't lose/forget the spring on the shaft.

i dont think thatll last john, it looks unsafe. ship to 49651 and i will properly dispose of it for you.








(is there a "jealous" smiley?)