Chain tension

[Tango42]

Ive been on a mission the last few nights to seal up the leaks in my superchief. Ive taken all the outer hubs/bearings apart and resealed them. All the bearings/axles/sprockets are in good shape. Now that its all back together, everything looks good except for the right front chain. The tension on this chain goes from tight to real loose over each rotation of the sprockets. When I spin the wheels, everything seems to run very true....nothing bent. I'm not sure if it was like this before I took it apart....I hadnt messed with the front chain tension until now. The chain seems good, sprocket looks good......what am I missing?? Any ideas?

Thanks,
Ron