I think you'd feel the awfulness if it stripped teeth. I lost a tooth on mine and it was a terrible racket that I'm pretty sure I felt in the shifter.
I think it did stripped ALL teeth off. I lost 5th gear under boost towing my xj uphill with cruise control on. The awfulness, terrible racket was loud and shook my truck.... no way I could've reacted fast enough to 'save' whatever left on 5th gear as the cruise control fully send it to try hold 70mph.
I read that 5th gear nut usually backs off and lose 5th gear quietly after either shifting or coasting, never while under load....
the big question mark is did it fuck up the shaft with however it failed.
quad4x4 I think is who had all sorts of good info and what at the time I thought was the best fix, but it was on a new style shaft with better support f or the gear I think
the 'permanent' fix by torque king is discontinued
I believe there are only 2 imported full spline main shafts to choose from. I read that the one with 3-piece thrust washer is the best option on the market. The 5th gear nut will not come off, BUT the mainshaft and the 5th gear are 'wear item'. Their spline will eventually wear out and strips as the 5th gear is not press-fit whatsoever and get side loaded by the gear below and changing in power flow via accelerating and coasting. New-Venture fucked up the design on nv4500.
https://torqueking.com/product/721/qk1001-dodge-nv4500hd-4x4-mainshaft-5th-gear-and-nut-kit/I will reuse the existing mainshaft if the 5th gear nut held on for it's dearest life and the gear teeth lost.
No way I will toss it if the 5th gear nut stayed on lol