Lexus Repair: timing belt tesioner, crank shaft, water pump replacement

Question
I have a 1990 ls400 that required the serpentine belt tensioner to be replaced.  After finding your advice on the water pump replacement, I haven't had trouble taking it apart and putting it back together.  Except for the timing belt tensioner.  Where the 2-12mm bolts hold the housing.  The center pin hits against what looks like a pin in the block.  Have I changed the timing or something?  I suspected it to drop right in and I would be done.  Can you suggest a fix?

Answer
BY GOING OVER YOU'RE QUESTION, IT SEEMS THAT THE CENTER PIN ( IN THE TOP OF THE TENSIONER) IS STARTING TO CONTACT THE TENSIONER BRG ASSY. AND RIGHTLY SO.I THINK THAT YOU HAVE NOT COLLAPSED THE TENSIONER FIRST, BEFORE INSTALLING.IF YOU PULL THE RUBBER BOOT OFF THE TOP. YOU WILL SEE A HOLE IN THE CENTER SHAFT.YOU WILL ALSO SEE 2 HOLES IN THE TENSIONER HOUSING 180 DEGREES APART.FIND A DRILL BIT THAT FITS THESE HOLES. NEXT PUT THE TENSIONER IN A VISE, LONG WAYS. START TO TIGHTEN THE VISE DOWN IN SMALL INCREMENTS, (1/4 TURN). AFTER EACH 1/4 TURN WAIT A LITTLE BIT. THIS IS DUE TO THAT THE TENSIONER IS SILICON FILLED.IT TAKES AWHILE TO CATCH UP.ONCE THE CENTER SHAFT HAS COLLAPSED COMPLETELY INSTALL THE DRILL BIT INTO THE 3 HOLES. ONE THING I HAVE FORGOTTEN TO TELL YOU. BEFORE YOU PUT THE TENSIONER INTO THE VISE,ALIGN THE 3 HOLES IN A STRAIGHT LINE AND REINSTALL THE RUBBER BOOT.RELEASE THE VISE AND THE DRILL BIT WILL HOLD THE CENTER SHAFT.INSTALL THE TENSIONER TO THE ENGINE.MAKE SURE ALL TIMING MARKS ARE CORRECT. THEN PULL OUT DRILL BIT.THIS WILL RELEASE TENSIONER.TURN CRANK SHAFT OVER 2 TIMES. THEN RECHECK MARKS.
GOOD LUCK