The Mighty Merc – Shaving the NP205

I knew I was planning on running a doubler setup in this rig (more on that in a later post). I wanted an economical, and robust transfer case for the rear that could be twin sticked. There really are only two options when it comes to this, either the D300, or NP205. The D300, while available cheaply, tend to get expensive once you start needing to beef them up. Considering that this this will likely be a 6,ooo lb rig with a decent amount of gear reduction I was worried about making a D300 live even with the heavy duty components.

That left the NP205 as the likely candidate. However, these things are massive and they have large boss that just kind of gets in the way of everything if you want to clock it up any. So I found a NP205 for $100 delivered (photo after LOTS of grease was cleaned off of it):
Sara L.: Driveline &emdash;

I then twin sticked the thing using one of the many write-ups floating around the internet:
Sara L.: Driveline &emdash;

Stripped the case and marked where I wanted to cut:
Sara L.: Driveline &emdash;

My grinder let out the magic smoke, so I wound up taking the case to work and milling the surface flat:
Sara L.: Driveline &emdash;

Which left me a case looking like this:
Sara L.: Driveline &emdash;

And a hunk of the boss like this:
Sara L.: Driveline &emdash;

Ground a piece of 3/8” plate to stick on top:
Sara L.: Driveline &emdash;

Preheated the whole case to 300°F, MIG’d it while still heating it (Weld, reheat, weld), reheated the whole case up to 300°F after the last weld, and wrapped it up in Fiber-Frax. The Case was still at 90°F the next day after spending the night in a 40°F Shop:
Sara L.: Driveline &emdash;

The end result:
Sara L.: Driveline &emdash;

Sara L.: Driveline &emdash;

Assembled, Primed, and Painted:
Sara L.: Driveline &emdash;

I did wind up adding another mount to the NP205 to replace the one I cut off. I’ll address that in a later post. There was also an adaptation for the VSS since the axle I’ll be using in the rear doesn’t have a provision for a tone ring. That will come up in another post as well.

Up next, the doubler!

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