Have seen old cast iron T-Cases crack and have seen some of the NP cases crack, but the difference is that some of the NP cases are made from either aluminum or MAGNESIUM
I'd not fix any and get a uncracked/busted/etc junk yard case and rebuild it
This image is a busted NP T-Case and most likely driven in 4x4 lock on pavement or on good traction surfaces. The below link is to a site that addresses the age old non-4x4 or newbie-4x4 person asking and/or folks providing advice (sure you can) if it is okay to drive on pavement in 4x4 lock...of course a standard 4x4, not all-wheel or full-time...NO IT IS NOT OKAY to drive in 4x4 lock on good traction conditions
Here is why part time 4WD should never be used on dry pavementThis image show why...
dodge guy wrote:
I would go reman or low mile used. I've never seen a T-case blown up!
How did you do it? Curious!
-Ben
Picture of my rig1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...