This is a write up on the conversion to full width axles I did on my 92 YJ. The axles are 3/4 ton GM with 4.56 gears. This is my first write up so it is in no way a complete step by step how to. If any one has questions on this conversion just ask. I have done a couple of these conversions and am always willing to help out a fellow wheeler. I want to thank crossed and guyer for there help when an extra hand was needed, Morning star for her patience and RNITOVR for supplying some much needed parts.
There are several things I had to change for this conversion. The stock front axle has drivers side diff and the 3/4 ton is a passenger side diff. To solve this I switched out the old NP 241 t-case. I found a Dana 300 out of a 84 CJ7. This is a gear to gear case and a popular case for its strength. The Dana 300 will bolt to the AX-15 tranny kind of. The bolt pattern is the same and have the same spline count, but the input and output shafts are to long. It would also hang lower than the stock t-case. To fix this I made a clocking ring and spacer. Switching to the 300 also meant rerouting the exhaust, and making new driveshafts. I am fortunate to have had the opportunity to learn the skills and have resources to make most of the parts myself for this project, but they can be bought from several places.

The Jeep before the conversion

Front axle ready for install. Spring mounts are only a 1/8" wider each side than stock YJ. So its pretty much a bolt in job

Rear axle with mounts cut off. Mounts need to be moved in to match YJ springs



Axles bolted in and ready



Old t-case (NP241)

Clocking, spacer and driveshaft flange rings before finish work

Clocking ring drilled and tapped

Spacer ring drilled

Clocking ring and spacer installed on Dana 300

Floor cut out for install

Bo the shop puppy always ready to help

The exhaust rerouted down driver side and out stock location

New rear driveshaft with drive flange

The finished floor with twin stick shifters for the t-case

Front brake calipers need to be "machined" a bit to clear 15" rims. Thanks to RNITOVR for the flat top steering knuckle and crossover steering arm.

Traction Bar. A must have for any spring over axle conversion (SOA)

The finished project




As with any project I still have a few "bugs" to work out. The speedometer drive has to be installed from the old t-case. This not being in yet has caused a few issues with the fuel injection and caused oil to leak from the t-case all over the rear axle.
I can't wait to see how it all works on the trail.