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AdamL · 05-08-2024, 05:22

I have a 1994 Oceanis 400 Beneteau rigged with a Z Spar in-mast furler. I believe that it is a Z600E mast section. The furling mechanism seems to be an earlier version of the more common system which has the spiralled furling drum. In my case, the lower furling mechanism has a smooth drum and can only be repaired/maintained by dropping the whole rig and pulling the mechanism out through the bottom of the mast. I have been unable to find any details or diagrams online so I thought I would add these notes and photos to the global knowledge base.

The lower furling mechanism can be removed by removing the gooseneck fitting attached to the mast with 6 rivets and 2 bolts. Once the rivets have been drilled out and the bolts removed the gooseneck fitting comes off, releasing the furling mechanism which can be pushed/pulled out the bottom of the mast.

As it turns out, the furling line is held in the furling drum via a captive plate on the inside of the drum. When the hex bolts (which hold the furling line in) are tightened they compress the line to the inside of the furling drum. With the system, the furling line can be replaced without removing the furling mechanism out of the mast.

The halyard swivel can also be slid along the furling extrusion and out the bottom of the mast for maintenance.

The lower furling mechanism is a fairly simple system with the furling drum held inside a thick-walled tube by internal circlips (size 90mm) at either end to hold the bearings and drum in place. The end caps of the furling drum hold the bearing races in place. The bearings are “steering gear” or also known as “head stem” bearings consisting of an inner and outer race that sandwich 52 stainless steel 5mm bearings. The external dimension of the bearings race is 90mm with an internal measurement of 72mm by 7mm high. The tubing which makes up the drum is 70mm OD by 500mm long. It was hard to get a wall measurement, by it appears to be 2.6mm thick??? (Don’t trust this measurement).

The halyard swivel again is a simple affair, the internal bobbin is held in place by an 80mm internal circlip. However, to remove the bearings and bobbin you need to drill out the 4 rivets which hold the 2 plastic spacer plates in place. Once the rivets are removed this will allow the whole internals to slide out. When sliding it out, do so in a bucket or over a fluffy towel, because bearings are guaranteed to go everywhere. Again, the bearings (one at either end of the bobbin) are steering gear bearings consisting of an inner and outer race that sandwich 43 stainless steel 5mm bearings. The external dimension of the bearings race is 80mm with an internal measurement of 62mm by 6mm high. Observe and remember the bearing races orientation when you disassemble the system so you can put it back together the same way.

In my case, the bearing races of the furling drum and halyard swivel were in good shape (impressive after 30 years) and all I needed to do was give everything a good clean with de-greaser and replace the bearings with new balls. To assemble the bearings (again over a fluffy towel, you’ll drop one or two), place one race onto the furling drum (or bobbin) add grease to the race to make it “sticky” and place each ball one by one until the race is full using your wife’s best tweezer (she’ll total understand and love you that little bit more). Place the top race in position and hold everything in place with the circlip. I lubricate the assembled bearing with lithium grease because I think everything is better with lubrication. I understand stainless steel bearings can be run dry at low speeds, so what you do with your balls is up to you. I did find that Z Spar suggested maintenance is to grease the bearings with WD 40 or Harken lube.

See below for some pictures.