Pto instalation

[charginj]

Hi all i have installed a pto onto transfer case but it doesn't seem to engage properly. I haven't installed the shifter yet but if you pull on the linkage to engage the pto it seems to mesh but if you rock the pto out put shaft back and forth it pops out. I have installed the pto using a gasket sealant but was wondering if it is supposed to be shimmed out or i am supposed to use a certain thickness gasket.
Any help would be much appreciated
Cheers Jason

 

[cruiser_guy]

The gasket thickness should not matter.

See if it's really fully engaged. You say it "seems" to mesh.