88 YJ-CJ Transfer Case Shifter

April 10, 2022

88 YJ-CJ Transfer Case Shifter

Jeep TJ Distraction...again:

There was a short, one-day distraction to replace the Rear Main Seal again - I failed on my first attempt. An entire team of Austin Jeep Exclusive folks helped out with the seal - thanks to everyone! I'm crossing my fingers that this one will hold.

The lift made this so much easier - thanks Gordon!

Transfer Case Final Touches

The rear flange arrived, and I got the NP231j all buttoned up.

The Front Yoke Got Cleaned and Painted

New Rear Flange Installed

The NP231J was out of a TJ, and had an incompatible shifter arm. I had to dig into my parts pile to find a YJ shifter arm to match the YJ shifter that I am hoping to use.

(Spoiler Alert: the YJ shifter worked well!)

Different Shifter Arms - I need the YJ-type

Transfer Case Shifter Options

Stock YJ Shifters (and background info):

In a YJ, the transfer case shifter mounts directly to the transmission. There were 4 or 5 different types of shifters that mounted differently to all the different transmissions (AX5, AX15, BA10, Automatic, etc). The YJ shifters work well, but it's a pain to have all the different types of shifters. Since I am attaching to a TH350 transmission - no stock shifter will work without mods.

Stock YJ Shifter

Cable Shifters:

I could have purchased a transfer case cable shifter. These are very popular with the TJ folks. But that would be $200-300, and all these small purchases add up! And I would also have to figure out mounting, modify the floor, drill holes, cut holes, etc. The cable shifter remains my backup plan if I fail with less expensive options.

Cable Shifter

Aftermarket Shifter Brackets:

My other option was to use the aftermarket YJ shifter that came with the Jeep. The shifter handle is stock YJ, but it bolts to an aftermarket bracket (probably from Novak or Advanced Adapters). The aftermarket bracket mounts to the transfer case mounting studs, which is pretty clever and convenient.

Aftermarket YJ Bracket

One complication is that my TH350 transmission has a thick aluminum Novak adapter to convert to the NP231J.

Shifter Modifications:

As always, nothing ever just bolts right together 😒

I did a test fit, and there was interference with the Novak Adapter at one of the holes.

First Test Fit

It also sits up way too high - that's a side effect of the tummy tuck and flat skid plate.

Sits up about 1.5" too high

Upper Left Mounting Hole Interference

It was pretty obvious what needed to be done:

Modification 1:

Clearance the Novak Adapter to fit the shifter bracket - this will be done on the mill.

Modifcation 2:

Cut 1" of the shifter bracket to lower it. It will still be 1/2" too high, but I can live with that. Or even shorten the shifter arm later to compensate.

Modification 3:

Clearance the Novak Adapter more to clear the shortened shifter bracket.

Area to be removed

Novak Adapter Mods:

I removed the Novak Adapter - this was already planned so that I could replace the two seals:

I set up the Novak Adapter on the mill and started cutting:

Finished Milling

Shifter Bracket Mods:

Silver Lines show the 1" Cut

The First Cut

2nd Cut

Test Fit

The 3 Pieces

Tacked Back Together

No picture, but it was fully welded at this point. I still need to paint it.

Test Fit:

The test fit was very successful - the shifter fits the Novak Adapter and it is sitting much lower.

Installed - temporary bolts used in place of the Transfer Case Studs

After Modification - much better

After Modification - not perfect, but pretty good

After Modification

Shifter Rod:

I dug some shifter rods out of my parts stash - one of these should work well

(or it will be relentlessly modified until it fits 😈).

Shifter Rod between Handle and Transfer Case

I ordered a couple of new shifter bushings too.

As a side note, on my 95 YJ, I replaced the factory rod with two mini-heim joints. That setup works great, and that will be my backup plan if the factory arm/bushings are problematic: