Setting Propeller Torque

Can someone please clarify how I am supposed to set the torque on the nuts on my front propeller shaft when I can barely get a wrench on the nut because of the clearance?
Thanks.

 

Closed end wrench and two fingers of grunt.

 

'Till the elbow clicks?

 

Rotate the shaft. The nuts on the top have more clearance.

 

Lockwashers AND self-locking nuts? Who needs torque?

 

My torque spec on those is as tight as I can get it with a normal combination wrench. Haven't had a failure in 30+ years doing that.

 

Yep, just as tight as you can get it with a normal combination wrench. If you tighten it enough to break the bolt you are stronger than I am, and in that case back off a little.

 

This.

 

I don’t want my hardware to be the weak point! I appreciate all the great advice.

 

You might enjoy reading Caroll Smith's publications on fasteners. Or take NASA's opinions into consideration.

Neither one believes that lock washers help.


NASA Reference Publication 1228 (1990) “Fastener Design Manual” addresses fastener material selection, platings, lubricants, corrosion, locking methods, washers, inserts, thread types and classes, fatigue loading, and fastener torque.

• The section on lockwashers states:
lockwasher of this type is useless for locking.

 

I have a special combination wrench . that I ground OD down on box end
stays in tool box . so it never gets lost
torque - good an tight

 

Wow, y’all torque stuff?

 

I will check that out. Thanks.

The prop shaft u bolts had nylocs and star washers when I got the jeep. I replaced with grade 8 yellow chromate partly to minimize rust.

I have been reading a lot about lock washers (and thread lock) and the only lock washer that has consistent endorsement is a nordlock. I have a few of them but didn’t think I would need it here because I was also using a Nyloc. This split lock washer fits in the space a little better than a flat washer.

Even though split lock washers “don’t work” I saw several fasteners that had marks cut in where the washer ends were engaged. That may not hold up with time. I’m primarily relying on Nylocs if not in a heat sensitive area and thread lock if in a heat sensitive area.

 

I use grade 8 self locking (nylocks) on those. Never had one loosen up. McMaster-Carr items. Like others, just a box end and as tight as I can get them.

 

These really only need about 15 lbs of torque. The caps are actually easy to overtighten causing pre mature failure of the joint.

 

Loc tite?

 

I’m not sure how this will show, but I bought a new 1/2” wrench and chamfered the side I was putting in toward the shaft that gave me enough clearance to get around the nut, but left a significant amount of the structure intact.

 

That would have been the trifecta - loc tote, nyloc, and lock washer. Going nowhere!