drive shaft stuffing box

[Tudorsailor]

Surely the way to check the thread direction is to get a nut of the correct size and put it on the end of the threaded rod and see which way it turns

TS

[pcmm]

Originally Posted by Tudorsailor

Surely the way to check the thread direction is to get a nut of the correct size and put it on the end of the threaded rod and see which way it turns

TS

The easiest way I've learned to determine thread direction (or handedness) is to see which way the threads "angle". If they are angled upwards to the right, its a right handed thread. If the threads angle up to the left, its left handed.

[Dieseldude]

Scubaseas' induction heater suggestion is a good one. This would supply concentrated heat exactly where needed without the hazards of a flame torch. Induction heaters are somewhat exotic though due to their cost. So not a lot of mechanics have one. Not sure if one could be rented from a rental shop. Penetrating oil of course is a good basic start. It can help to heat the nuts before applying penetrant. Just a mild heat that will not burn the oil should be used. Tapping the nuts will make vibrations that will help the oil to penetrate. An impact wrench that is operated by hitting with a hammer would target the vibrations exactly where needed. An impact grade socket is recommended, as a regular socket can crack. I am assuming that the nuts are conventional hex nuts. For these, a six point socket is essential. A 12 point could easily round off the nut corners.

I once had to slack off a gland, but the studs were too short for leaving them in place for emergency sake. If packing is being renewed while the vessel is floating, some studs must remain in place to enable emergency re-tightening of the gland against water pressure. They must be of sufficient length to allow enough retraction of the gland access for fitting a new wrap of packing. After slacking back each nut, I fitted a jam nut on each stud. One at a time, I exchanged each short stud for a longer one. This enabled the gland to be retracted, but some studs were left in place to make it possible to tighten back the gland in case of a packing blow out which could sink the vessel. Before doing anything, I trimmed the vessel to the head as much as possible. Decreasing submerged depth of course decreases water pressure on the packing.

If all else fails, a Dremel type tool or dye grinder may be the remedy if sufficient clearance is available to get the tool in. Rig on a slitting saw or thin grinding disk. Cut across the width of the nut. Depth of cut must be controlled to not cut into the stud if you plan to re-use them. But there is a problem in that the rotating cutter or grinder will not bottom out against the gland, leaving a portion of the inner end of the nut uncut.

This would require application of brute force with a hammer and cold chisel to completely split the nut. The chisel must be heavy enough to apply sufficient force. A light one will only bounce. It must be well sharpened. There is some risk of damaging the gland and studs when the chisel suddenly moves toward them. Before trying the chisel treatment, the nut may release with application of force by a wrench, as the cut slot will have released some tension. Doing surgery on the nut is very much an all or nothing approach. Once begun, there is no undoing the cut. If one cut does not work, make another on the opposite side of the nut. I did not have to try this, but if a hole can be drilled into the end of the nut that is against the gland, this will remove some material that the disk cannot access. If a grinder is unavailable, a row of holes along the thickness of the nut might remove enough material for a cold chisel to complete the job. This is quite a precision drilling operation requiring good technique and a high quality sharp drill bit. Starting points must be center punched to avoid the drill skating off location. A combination drill as a starting drill would be useful. These have a reduced diameter point that is less prone to wander. They can be had in various diameters at machine shop supply stores.

Instead of the nut splitting approach, you choose to heat with a flame torch, setting wet rags over flammable items nearby can help to avoid fire. Just wet them periodically if the flame dries them. A pump sprayer or garden hose close by is essential.

Good luck, and for next time, you can apply a suitable anti seize compound to the studs to avoid all this.

A tip on direction to turn. This can be confusing when threaded fasteners are situated in odd places. You can set a ratchet wrench in the correct direction whole holding it normally, in this case for "off" or counterclockwise. Then position it over the fastener. Give it a twist and you will know that you are correct.

[Dieseldude]

Note that my experience was with a steel hull vessel with the stuffing box well secured to the hull. Some folks have noted leak hazards with stuffing boxes in fiberglass hulls. These installations would require that the stuffing box be well secured for applying a lot of force to gland nuts.

[littledave]

Originally Posted by tkeithlu

Wow! That sounds like a good way to shear the bolts. How about
1. soak overnight in penetrant
2. tap tighter then looser according to beetle's method but maybe without the three pound hammer. A 1/4 inch impact driver or maybe an air wrench would do.
3. that fails, get out the torch and both burn off the corrosion and get some differential expansion to work for you.
4. If that fails, get out the big torch and soften the nuts.

Saw a very good boat mechanic use a small but hot gas torch to just heat a seized nut on our exhaust manifold. It freed the nut off the stud and while nut was already burred from our attempts to undo it, the stud was fine.

[gregorybross]

I would discourage any hammering on the lock nut. Mine cracked so I had to replace the entire stuffing box. Since the flange attached to the transmission was frozen on athe flange, shaft and stuffing box all had to be replaced at considerable expense.

[Bill Creadon]

When I bought a 38 Catalina Morgan from Cooneys on Long Island Tyler Cooney was going thru the commissioning and taught me to use a blunt object (a 6” piece of drive shaft which he gifted to me) and tap the locking nut with several strikes and it will loosen. He explained that bronze components will work loose with this method. I have been using this method for 25 years thanks to Tyler Cooney. I found many uses for that blunt object.

Georgia Song

[Finalee]

Originally Posted by Boatyarddog

I've not seen Left hand threading on packing glands yet.
You first response is very sensible.

I've used a wide flat punch striking the flats of the locking nut on their rise.
Be sure you don't mangle it to much, you can file the flats if you have to.

I use Kroil, PB is good too, acetone and trans fluid is good.
A bit of heat.

Be sure your moving the nut CCW, looking from behind the nut forward to the bow, or engine
CW if from the bow looking aft toward your rudder post, or stern.
This can be confusing to some.
SV Cloud Duster

This works well in the right hands.