Ultradot Gen 1 elevation adjustment housing coming loose?

I have a middle-age Ultradot Gen 1 where the elevation adjustment stopped "clicking" in the upward direction?  It would move, but was just a smooth turn without any clicks.  After fiddling with it, I realized the housing (the outer metal tube where the cap screws on) had become loose somehow?  I could turn it down into the main body with my fingers and tighten it up, and after doing the click adjust worked again in both directions.  Tightening the housing also moves the dot, much as turning the click adjust.  I then gently tightened the outer housing with a pliers and rag, but realized it was snug, but not hitting any end point?  I don't want to over-do it and kill the unit completely.  Equally, I want the unit to hold its zero.  Should that outer housing reach a point where it doesn't tighten any further?  In other words, go ahead and keep tightening until it grounds out?  Or is "snug" what I'm after?  It seems like it could loosen itself up with recoil, and I'd not notice except my shots would start to be off zero?   I haven't had this problem before so curious other experiences and repair suggestions anyone might have?  I could take the elevation insert all the way out I suppose, but not sure what good that woudl do.  Or send it in, but I don't have the receipt so won't get it done under warranty.  If I can fix myself I'd prefer to do. Would thread-lock work?