NP246 to NP241

This information is already in my SAS build, but i wanted to make some smaller articles available.

If/when doing a Solid Axle Swap (SAS) in a NBS silverado, the NP246 autotrac transfer case will not work for several reasons:

1. The elimination of the ABS and front speed sensors will cause the auto 4wd to burn up and ruin case.

2. A fixed yoke is needed for the front drive shaft rather than the 246's slip yoke.

So what do you need??? A NP241 from a OBS, mid 90's to 98. If you have a automatic, make sure you get a transfer case from an automatic. If not you will not have the proper splines on the input shaft. The NP241 VSS will work with your current computer and will wire up in 2 seconds.

Another advantage of the NP241 is that a Slip Yoke Eliminator (SYE) is available for a rear drive shaft with a severe angle. This will eliminate that well known ''clunk'' and add strength to the tailshaft.

http://www.ls1truck.com/upload/files/198/246to241.JPG

Looking at the two cases, you will see that the 246 uses studs to attach to adapter and the 241 uses bolts. Just use bolts and the original 246 adapter which is on your truck, DO NOT use the NP241 adapter. It just won't fit.

Once the 246 is out and the 241 is in its place you are going to have alot of extra wires. The only wires that matter are the two wires for the original VSS. The two wires are green and purple. You can either buy the pigtail for the 241 VSS or simply solder two wires to VSS and silicone them as I did. Saves you the cost of the pigtail (roughly $48 from GM).

http://www.ls1truck.com/upload/files/198/241wired.JPG

Install the rear driveshaft, which will match right up, and verify that you are getting a reading to your speedo. I taped up all my extra pigtails and wiring because you just never know.

As for making brackets to hook up the manual 4x4 shifter....I am lazy and haven't done it yet.