The other day while driving my truck I lost 5th gear. (Imagine that?!) At the time I didn't think much about it thinking it was just the nut that had fallen off. Instead of repairing the problem with the trans in the truck I decided to take it out and fix my occasional scuff I had when shifting to 3rd while I was at it. After I removed the transmission I was shocked when I seen that my input shaft was nearly twisted in half!!:--) . After few minutes of standing there in disbelief, I decided to tear into the trans to see what else was wrong. When I pulled the rear cover off I was shocked again when the 5th gear nut was still tight on the shaft. By then I was thinking that the mainshaft and/or 5th gear splines were stipped. Not the case, The 5th gear collar on the countershaft was stripped and wiped clean of teeth. Luckily I had a spare NV 4500 with the parts to fix the problem. As for now I waiting on a Input shaft and synchro blocker ring from Zumbrota. I am now really thinking hard about a 6 speed conversion, but hate the way they shift compared to a 5 speed. The funny thing is that the friggin' lube juice for the trans costs as much as the replacement input shaft! Go figure!