Well, a call to MOR/ryde reveals that the recommended torques are as follows:
The 7/16-14 UNC X 1.25 long (grade 5) bolts for the Z-Bracket to rubber shear spring connection calls for 40 ft/lbs., as per the following torque chart in their RE kit installation instructions. See page #2. (As a side bar, notice the shocks in the drawing. Very interesting! But, that's another topic of debate!)
MOR/ryde RE Installation Instructions
The 7/16-20 UNF (grade 5) wet bolts(a Dexter part) with the zerk fitting, they said 30-50 ft/lbs, as per the following Dexter document. See page 6, step #3. Based on torque differences between the two thread pitches of 14 tpi(threads per inch) vs 20 tpi in other charts, I would recommend 45 ft/lbs for the wet bolts.
Dexter Axle document
Tom S. and Art-n-Marge,
A torque value is not usually a valid consideration for NPT(National Pipe Taper) fittings, except, that aircraft applications usually require torque tolerances to comply to their standards.
Generally, in a typical non flight-critical application, the tapered female threads are supposed to be tapped to a specific pitch diameter at the top surface of the hole, using a special go/no-go gauge to determine that tolerance. For the mating fittings, the zerk in this case, as a general guideline, after finger-tight engagement, tighten a further 2-3 full turns for sizes up to 1 inches for NPT fittings.
Most people use "feel" for proper tightness to assemble NPT fittings to achieve the sealing properties which they are designed for. After you snap a few of these things off, you soon get good at it, trust me! Also, if a fitting is used in different materials (aluminum, plastic, brass, etc.), Torque goes right out the window, because a tapered thread can easily strip the threads or even crack the part that the fitting screws into.
Now that I have thoroughly confused everybody with the mystical intricacy of proper NPT tightening, all of this goes out the window with these wet bolts! On the ones that I received, the shoulder of the zerk bottoms out on the face of the bolt. Not at all a proper exercise in NPT correctness! If the fitting bottoms out before the tapered thread engagement seals, you will never keep it from leaking through the threads.
.....But there is still joy to be had. Since there is no pressure to cause a leak in the threads(to wit: the grease will be leaking out at the ends of the bushing anyway), it's all a moot point.
So, for this application, you just need to tighten them enough so they won't be loosened by the grease gun tip when you pull it off of the zerk. I really think that 20 ft/lbs is
way too much if you feel the need to have to use a torque wrench on the zerks. 5 ft/lbs should be more than enough, unless you think you need to get in some practice using your EASY-OUT broken bolt extractor set.
....We now return you to the regularly scheduled program.
