Did a search and apparently nobody tightens these with an impact gun. I torqued them to 150 ft/lbs, max for my torque wrench. I don't want to try to reach the 180 ft/lbs with the torque wrench; don't want to throw it outta whack. AND I don't have a second 1/2" drive breaker bar.

So I can I just support the bolt from behind with a socket & breaker bar, and tighten the nuts a little bit with an impact wrench? Any harm in that? Those f'ers are thick as hell, I don't think I'll snap 'em.

 

Sure. I did. In fact, I couldn't get mine off even with my Snap-On. I ended up using a 24" breaker to start them. If an impact can't get it off it sure can't overtighten it. They are rated higher in reverse torque. I SERIOUSLY doubt you will break them or strip the threads. The are quite beefy

 

No kidding! Hey, thanks, I didn't know that about the impact wrenches. (Mine is a Campbell Hausfeld PL1502, nowhere near as good as a Snap-On! ) Good, I'll go give them their "final tighten" when I get home. And I'll put "second breaker bar" on the tool wish-list. Thanks man!!

 

To tighten mine I put a 4' pipe on my 1/2" ratchet and gave it a good pull, nothing broke. Bent my good Taiwan ratchet a little though.

 

Are you sure it's not 180 Nm instead of ft.-lbs.? I torqued mine to 125 ft.-lbs., and I'm pretty sure the spec sheet mentioned 180 Nm.

 

Different years will say different things. My 86 Helms says 195 ft-lbs, when my 92 helms says 125lbs+120 degrees (final torque must exceed 148ft-lbs).

 

Actually the sheet I used said 170 Nm (125 ft.-lbs.) and a 120 degree turn but the final torque must not exceed 148 ft.-lbs. The parts should be the same for all years, I wonder if they found a problem with torquing it at 195 ft.-lbs. and changed the specs?

 

My GM manual for 88 says 202 ft lbs for the torque.