How to torque drivebelt tensioner pulley bolt?

When I was taking my engine apart, I think I may have made the mistake (or not?) of removing the drivebelt tensioner pulley off because reinstalling it involves turning the reversely threaded bolt counterclockwise, which also flexes the whole tensioner. The reason I am saying this is because I just broke the bolt thinking the torque wrench was still accurate even with the tensioner turned counterclockwise on every turn but it wasn't and I applied waaay too much torque until I broke the bolt. The extenuating circumstance being that I was able to extract the broken piece out so now I need to order just the bolt and not the whole tensioner (which I hope to find separately and not have to buy the whole thing).

My three questions are:

1. How to I reinstall this tensioner pulley considering the spring compressing when I turn it counterclockwise? Is there a way to lock the tensioner while torquing the bolt for the pulley?
2. I tried RockAuto and googling for the part number for just the bolt but couldn't find. Do you know the part # so I can order from a Toyota specialty parts store online?
3. The manual does not provide torque spec for the tensioner pulley but says 40 ft/lbs for the three regular idler pulleys. Is it the same torque for the tensioner pulley bolt?

 

I think the Haynes manual covers that.

 

You can lock the tensioner back.
There is a hole that will line up once you get it in the right place.


What isn’t clear is what you mean by inaccurate?
There isn’t a clear TQ spec that I know of, but there are claims of it being 39 ft/lb.
39 ft/lb is 39 ft/lb. Either the spring will be “weaker” than 39 ft/lb, or it will be stronger than 39 ft/lb.
If stronger you should get a click.

I’d probably just remove the belt, grab the tensioner pulley, and hold it to torque it.
And that’s IF I torque it.

I’d test my TQ wrench first.
The rule of thumb is that it generally take 10% less Torque to loose a bolt.
Therefore, if you are testing a lug nut, you want to tighten the lug nut to 10% more than the reverse bolt value.

And to be honest, I don’t alway fool with that.
I go by feel.

 

I thought the wrench would be getting an accurate reading (and click at 40) even though the tensioner was getting compressed.

Thanks for the rest. Do you know if it's possible to order just the reversely threaded bolt? It would be kinda stupid to have to buy the whole thing.

 

I think it might be one of the pages the baby tore in shreds recently LOL

 

I would think so, but you need to know the size, the pitch, and the length, and possibly the flange size at the head. I can not remember what the bolt looks like. But most pulleys use a flange type bolt.

 

Yes, it's a flage type. I will do the measurements tomorrow.

 

It will probably be metric.
So you’ll likely need to measure in mm.

 

Yes, here are the specs:

Head: 14 mm
Length (just the shaft, excluding head and flange): 40 mm
Thread pitch: 1.5 mm (M10, I think)
Shaft diameter: 9.75 mm (does that mean normative 10?)
Flange diameter: 24mm
Thread direction: reverse

Conversely, the idler pulley bolts are 35 mm and pitched at 1.25 mm, same shaft diameter, and normal thread direction (torqued clockwise).

So far, the closest I found is this but the head is 17mm instead of 14 and not flanged so I think it will fit.

 

It all looks correct to me.
Buy a single bolt is expensive. $26 BEFORE shipping.

 

Yeah I know. Stupidity carries a price. Still better than buying a whole damn tensioner for 80 + shipping.

Another silver lining is that I was able to extract the broken part and do not have to take the tensioner out, which means taking the AC pump out, which is a PIA.

The shipping + tax were another $9.