I can shift from 1st to 2nd no problem but 3 and 4 disappear. When I do find 3 and 4, 1 and 2 disappear. I changed the clutch 8 years ago but have maybe put 5k miles on my Van. It is a 84 westy. My mind says linkage but I am not very up on clutches. If you can point me in the right direction it would be appreciated. I am suppose to be going camping on Friday and would like to take my ride if I can figure out whats going on and fix it.
i went through the clutch pages but didn't see anything that resembled this issue
The clutch is not your issue. All it does it connect the flywheel (engine) with the driven plate (gearbox input shaft) and disconnect when you push the pedal. The selection of gears is as you suspect in the shifter linkage. There are numerous parts out there to address various issues but start by having a look and seeing if there is anything obviously broken.
Don't forget the engine/transmission mounts could be the issue. The shifter is located on the body and engine / transmission can move on mounts so if the mounts are excessively worn or break then they may move so that the linkage cannot compensate. This might be why you can get 1-2 sometimes and 3-4 other times; due to power-train movement.