track tensioner not moving while pumping the grease
work around salt water? I ask that because we had some dozers one time that worker on gas wells and were in the brim water it was amazing how bad they would rust up took a lot to get them to move The other thing is how worn is your under carriage 963s have two positions for the idler when it gets so worn you have to remove the bolts in bottom of frame and move it forward on roller frame
you can get this at O'Reilly's it is amazing
How about posting a photo showing the tensioner and idler.? As @pittsburgh cat man says it will be easy to see if the tensioner is fully extended and if the idler linkage is in the first or second position.