Cracked NP 205-Dead or repairable?

[KK5 Native]

I was in the process of rebuilding my NP 205 for the ORD doubler and when I was torquing down the shaft on the center gear cluster the cast iron case cracked. The torque for that nut is 90-130 ft. lbs. I was using a torque wrench and I was not over torquing it.

I'm assuming because the case is cast iron there is no way to repair it. Does anyone have any experience and/or success in repairing these?

 

[ryoken]

eesh, that's ugly...

sorry to say, I'd be looking for a new case.... could it be fixed? sure, but you factor in the labor to prep that, than the welding cast process, than the machining, tapping, etc needed, it'd be more cost-effective to replace the case... and obviously the cast welding aspect would always be suspect..

 

[nvrenuf]

I agree - dead and not cost effective to fix.

 

[KK5 Native]

Yeah that was pretty much my thoughts on the matter. I didn't want any weak links on the build up of the doubler because I plan to beat on it pretty hard once it's in.

I've got another NP 205 I'm going to tear down and rebuild. It's a 27 spline input so I'll have to get it machined out to accept the larger bearing and use the 32 spline input from the cracked case.

 

[sweetk30]

you sure the main shaft end was good ? looks little obb long in the hole .

or was there a chance something got wedged in there ?

its a straight shot hole on the back side and should have not done this . the main pulling load is the front of the case were the nut is on the shaft .

and if you need help with the build of the 203/205 ord kit look here http://coloradok5.com/forums/showthread.php?t=253000

 

[KK5 Native]

Upon removal of the shaft I found a small protruding lip on the end. If you look at the top pic you can see where the lip was before because there is a small gap on the case portion. Then clockwise up from that is the lip that was not installed back in the original indentation. I'm thinking that was the cause of the fracture.

 

[sweetk30]

yep something wasn't right and since-u-was the last one to work on it . . . it said hell no .

atleast its not a ultra rare case .

heck I have a brand new n.o.s. large bearing fig8 case in stock for a extra build when I am ready .