2ZZ belt tensioner adjusting 'nut' repair - now broken off

[sadavis80]

Anyone successfully 'replaced' the broken off 'nut'? Thinking I'll drill and tap through the center of what remains of the nut and put a BOLT in there. Would like to 'back it up' with a nut on the back of the arm, but doubt there's enough room. I also thought of moving the 'nut' further from the pivot bolt so the pull isn't quite as hard. I can't understand why all of the tensioners have the 'adjuster' so close to the pivot. The pull was so hard, I couldn't even tell when I was 'near the limit'.

New replacements must be made of Platinum and even those are SCARCE. I think I'll take a shot at fixing this one.

Thoughts?
OH.. 2005 Vibe GT - close to 200k.
Steve

[joatmon]

https://www.partsgeek.com/qfh2k45-toyot ... ioner.html claims to have one for $56 (likely +tax/shipping)

[sadavis80]

Yeah,!claims!. But the proper one for the 2ZZ is $261.76 - actually BOTH *SAY* they are 2zz. I already gave it a shot and had to send it back.
The $56 one is for the 1zz. They DO LOOK similar at a glance but there are several subtle differences that make them NOT COMPATBLE.

Hard to justify the difference in price...but they come out of different molds and I guess they sell a LOT MORE of the 1zz than 2zz.
Tks for trying.
Steve

[joatmon]

I'm being pretty worthless for your problems

Is there enough clearance to run a bolt through from the back side?

[sadavis80]

"I'm being pretty worthless for your problems "...
Wouldn't say that ... BUT... I have taken some action.

No clearance to run a bolt from the BACK side, but I do have clearance to run one through from the front. Unfortunately, I didn't think to take a pic before working on it, but the original bolt-head was BROKEN pretty much OFF - even dipping a bit into the meat of the surface of the tensioner. I milled off all the 'crap' left over from the original and made a GUESS about how far I could go 'out' away from the pivot point ..and still stay 'within' enough meat of the arm so that it wouldn't break apart from the force.
You can see a couple pics and some writeup (giving info on tension arm difference 1ZZ vs 2ZZ) on my website at
https://www.wedgeracing.com/2023/Vibe_2ZZ/

This all started with my shredded belt a couple weeks ago.. viewtopic.php?t=48617. I watched some (MORE) videos about tension arms and figured as long as I was this far in, I would go ahead and see if I can fix the OIL LEAK that has plagued the car (and my garage floor). I've replaced the valve cover gasket, and the chain tensioner and it's oring TWICE with no improvement..so the TIMING CHAIN COVER GASKETS are next. ...2zzlow says "it's EASY.. simple stuff". I doubt that, but I'm ON IT

Steve

[tpollauf]

I watched some (MORE) videos about tension arms and figured as long as I was this far in, I would go ahead and see if I can fix the OIL LEAK that has plagued the car (and my garage floor). I've replaced the valve cover gasket, and the chain tensioner and it's oring TWICE with no improvement..so the TIMING CHAIN COVER GASKETS are next. ...2zzlow says "it's EASY.. simple stuff". I duotbt hat, but I'm ON IT
Steve

Visit this thread and you'll see where your oil leak problem is. It's NOT an easy job. I did not have time to fix mine so a mechanic friend of mine did it for me. viewtopic.php?p=521527&hilit=2004+GT+ti ... ak#p521527

[drfrisker]

The bolt head on my tensioner was rounded off befofe I did my timing cover reseal job earlier this year. I managed to reinstall it without using it, but it's not a memory I'd like to revisit. I used a c clamp in the perfect position on the tensioner to get the arm in the right spot for the belt to slide on. It's a huge pain in the (removed). The a/c hardliners are in the way and they might leak a little when you move them out of the way. A smaller clamp would work but holy guacamole.

[sadavis80]

Just a follow up... I finally got the engine back together and it was time to install the serp belt.. my tensioner arm 'fix' FAILED. The bolt I put through the arm, just stripped out. SO.. I had to fabricate a TOOL. Made it from 1/4 steel plate. Drilled a hole to put the plate over the arm mounting bolt with tabs to the front and back to get leverage on the original arm and pull it downward. I also bought a belt that is 3/16" longer than the original. Even with that, I was just barely able to install the belt. Interesting to me was that with my new pulley arm tool, I was able to pull the arm all the way to it's limit and it's really easy to see how the original 'nut' breaks off on these things. The shock/spring that controls the force on the end pulley is SO STRONG, that it's impossible to 'feel' the end of the travel. On every other serp tensioner (in other type vehicles), it was pretty easy to tell when you reached the end of travel, but this blasted thing is SO HARD to pull, you just can't tell.

That cast tensioner arm just doesn't have the strength in the cast 'nut' to pull that kind of load. My welded up plate tool, DOES have enough strength thankfully, but the job is still quite difficult. The movement of the end pulley is pretty short. With the end pulley almost touching the crank pulley, I could still JUST BARELY get the belt over the sides of the alternator pulley.

The GOOD NEWS, is that my oil leak is FINALLY FIXED!!. I got my broken liftbolt out, replaced the oil pan with one for a 1ZZ to get the additional baffling ..and replaced the o-ring on the chain tensioner in addition to the timing chain cover gaskets. I'm really surprised that I'm now burning NO OIL at all.. even with just under 250k on the engine. Cleanest my garage floor has ever been . OH.. I also replaced the PVC valve... it was 'messy' and was probably pulling some oil through there.

Side note - the valve cover gasket set, did NOT include a new o-ring for the shaft that connects the oil supply to the top of the valve cover to lube the camshafts. The cams were showing some significant wear .. I think because of lack of oil up there. The original o-ring was loose enough that I'm sure I was losing oil pressure to those vents in the cover that are SUPPOSED to be oiling the camshafts. Be sure to replace yours .. or at least check for snugness any time you remove the valve cover. It wasn't even mentioned in my shop manual, so I just searched my o-ring stock for one that 'felt right'.
Steve

[tpollauf]

Nice work! I've never had to mess with any of my tensioners yet BUT appreciate it when someone is smart enough and has the resources to create another option to solve a problem, and FIX it. I've had to fabricate several gizmo's and widgets in order to get me out of jams. Luckily I have the resources & tooling to do such work. Thanks for sharing!

[sadavis80]

Thanks.
I took some pix of the tool just in case someone needs to build one. It's a 'rough in', but it got the job done.
You can see it at
https://WedgeRacing.com/VibeGT/tensioner_tool.html

Steve

[zbyers]

I've only ever broken the cast hex/nut once on the dozens of Vibes I've owned. It was one with 250k+ miles on it when I bought it and changed the belt. I quickly learned that since it is cast aluminum, to stop once the tensioner stops; you won't have any more give and you will break that nut.

FWIW, I have a used OEM tensioner in the garage for a 2ZZ laying around if anyone is in need.

[sadavis80]

When I had everything out of the way to jack up the engine for the timing chain cover reseal, it was "easy" to SEE the end of travel.. however, with the engine in it's normal position .. at least on MY GT, it's pretty IMPOSSIBLE to see that 'end of travel' while pulling on a bar to release the tension and trying to get the belt over the alternator pulley. In my case, I'm pretty sure the length of the belt was the biggest issue. I'm almost positive that there really was NO 'effing way' that the belt (the shorter one that was on the car) was going over the lip of the alternator pulley. The ONLY way to get that one on would be to have the belt on the alternator, compressor and steering pump first.. and then slip the belt over the idler pulley last (no lip there). Again, using that method, your hand/arm would totally block any view of the 'end of travel' on the tensioner arm.

In addition, "Quickly learning" still meant you broke ONE - and that was probably 'some years ago' before they became as rare as hens teeth. That stupid arm sells for almost $300 now.. IF you can find one. When I was searching for a complete 2ZZ engine, I noticed that most of the offer engines did NOT include the tensioner arm. Some even included the alternator, some even included the A/C compressor. But only ONE included the tensioner arm and it was one of the most expensive ones.

Thankfully, as soon as I actually removed the crank pulley, the REAL problem was quite obvious and I saved myself $3G in dollars for a replacement engine .. not to mention the additional work of getting the axles and trans off and back on.

Interesting to me.. although I've worked on engines for many years and replaced LOTS of serpentine belts.. it NEVER occurred to me to buy a slightly LONGER belt to make the job easier. The guy at NAPA suggested it .. and it WORKED although it still took a LOT of pressure at the alternator. Of course, I have NEVER before encountered one where the belt was such a TIGHT FIT either. I had watched several 2ZZ videos where the guy doing the job (usually 2ZZlow) simply 'pulled the belt off .. and then 'just slipped it back on'. He OBVIOUSLY was using a longer belt - even longer than my 'longer' one I used in the end. The geometry of MOST tensioners is quite a bit more 'dramatic' than the geometry of the 2ZZ. I presume that's why the spring pressure on that arm is SO much higher (at least twice the force) than any other engine I have worked on .. including even my 360 HP CAT DIESEL motor home.
Steve