Snap on torque angle work backwards?

[sattech200]

Hi all. Doing head gaskets on a Subaru boxer engine. I believe Subaru has updated the torque specifications to the values below. My question is, is the snap on torque angle 3/8 safe/capable of measuring angles going backwards?

1 - tigten all to 22 ft-lb
2- tigten all to 51 ft-lb
3 - Back off all bolts in reverse order of assembly by 180° first;
4 - back them off by 180° again.
5 - tighten bolts (a) and (b) to 25 ft-lb
6 - Tighten bolts (c), (d), (e) and (f) to 11 ft-lb).
7 - Tighten all bolts by 80 to 90° in alphabetical sequence.
CAUTION: Do not tighten bolts more than 90°.

snapon: ATECH2F100GB

 

[PCustoms]

If not, how can you torque left handed bolts?

 

[N8sToolz]

180 is pretty easy to count with or without a torque angle gauge.

Those bolts will be completely loose by the end of that second backing off.

 

[dnschmidt]

Easiest way is to mark 12 o'clock on the bolt, I use a yellow paint pen and screw with the initial ********. which to me makes no sense. by simply looking where the mark goes. For the final sequence, which is all that matters, the torque angle will work perfectly.

 

[PCustoms]

Everything being a multiple of 90, you could easily do this by eye with a standard wrench.

 

[2ndGearRubber]

Yes it works backwards, I just tested it. For loosening specs I just use paint paints as it's much easier.

 

[2ndGearRubber]

I would not trust it for loosening. It only registers angle if there is resistance. For instance you could not thread a bolt down and register angle applied until the nut hit resistance of the fastener surface.

If the fastener becomes loose enough angle would no longer be logged.