yes, 90 wt. Does it grind or just acts like it is stuck? First thing I would do it verify it is not real low on gear oil. Then make sure your clutch is adjusted properly and disengaging all the way. (if the clutch is partially engaged, that can make it real hard to shift!)


Mike
1955 Chevy 6400 ex-flatbed (no bed now!) sold September 2023
In the Stovebolt Gallery
1958 Chevy 6400 flatbed W/dump
In the Stovebolt Gallery
1959 Chevy Suburban Owned for almost 20 years, Daily Driver -- sold May 2016
In the Stovebolt Gallery

Sufficient unto the day is the evil thereof