got a 2001 nv 4500 started grinding in third and fourth and took it apart and put scyncros in 3rd & 4rth and third gear in it everything looks great put it back together today and filled it with penzoil snycromesh oil and it still does the same **** any ideas

 

well any ideas

 

sometimes when starting my truck up and taking it out for the first trip of the day sometimes 2nd will grind a bit before going in, its cold up here and guess its just the thick gear oil? Dunno if its the same issue for you or not

 

Hey I done the same thing. 3rd is grinding. Put new synq in it and same problem.when ya find out let me know.

 

pulled mine out an had it rebuilt an everything is fine, maybe you did it wrong... just a thought.