2005 Pontiac Vibe GT - 2ZZGE engine  - approx 200k miles 10/2023

Tensioner Arm repair for broken pressure release 'NUT' on the original Aluminum arm.

Pic below shows the location where the 'NUT' used to be. Looking closely, you can see the 'divot' at about NNE where the original 'NUT' broke into the base metal.

Below and to the right of the original location, you can see the new 1/2" hole I drilled and tapped at my 'best guess' location. This is about 3/16" further from the pivot in order to improve the (HORRIBLE) mechanical (dis)advantage around the pivot bolt. That's "not much" change, but a decent 'percentage' improvement. When I milled the arm, it is not perfectly flat across the surface. For a metal casting it's MUCH easier to get the parts out of the mold if there is some taper in the surfaces.  SO.. the mill is flush on one side, but I didn't want to dig INTO the arm any more than necessary. Also in this pic, you can see the major difference between the 1ZZ and 2ZZ arms.  The left end of 2ZZ is LONGER to the shock/spring location - the 'roughly 45 degree angle of the 'cutout' where the belt crosses from the alternator to the power steering pump (that black mark is from the belt). The 1ZZ arm has a similar offset, but it's almost vertical. Across the bottom of the arm, it's almost straight, whereas the 1ZZ has a significant angle across the bottom. There is also a different distance from the pivot bolt to each end.

In the shot below you can see the bolt I added to replace the original 'NUT'. The bolt 'bites' into the back of the 'slant' a bit, but not enough to be an issue - it doesn't protrude past the edge of the backside of the arm.  I wanted the additional thickness of the NUT ON THE BOLT - to provide more material for a socket to grab.. and, of course THIS is real STEEL nut and bolt, whereas the original was just a chunk of aluminum, 'glommed' onto the side of the arm. I have high expectations that this part will NOT FAIL.  I'll be really TICKED if it does.

Before this goes in, I will be tig welding the new nut to the bolt, and then installing the combo with RED LOCTITE. *AND* I"m using a belt that is about 3/16" LONGER than the one that was on there.  Pretty sure I got the wrong belt last time.. meaning that the belt would JUST BARELY .. and I mean *BEARLY* go onto the aternator pulley.  The arm had to be stressed to it's limit to get the belt installed. Next time, it should be a 'piece of cake'.. sure :-).  I'm using (planning to use) a NAPA belt P/N PBH 6K747 .. as opposed to the Duralast 745K6.  I'll know more after I get everything all back together and (try to) install the new belt.