Pakkboks

[Bob Noodat]

Hallo, Ô Fountains of Wisdom..

I have been corresponding about an A25 for sale and the owner tells me it "has the original Albin pakkboks". He says that this is a dripless "packing gland" that uses two oil seals with grease and a bearing in between. Apparently this device is "almost maintenance free, and completely drip free".

Well, it is news to me and all searches end in Swedish. I have no complaints about that, but Google Translate always just ends up insulting my mother and telling me how to get to a sushi bar somewhere in Minnesota, so I thought it would be easier to seek more information from the horse's mouth, so to speak. Although if I then repeat it, it may change ends.

Any comments on the pakkboks would be appreciated. Is it a good or a bad feature? Not just a stuffing box?

PS. I did do a search in this subforum, to no avail.

[NickScheuer]

From your description I'd say we have a "pakkboks" in or 1976 Albin-25 Deluxe. Got news, for'ya, it leaks. I opened it up last season and thought it showed too little grease and too much airspace, so I packed in more grease. We had to decommission our boat too soon to determine whether the added grease is effective.

[NickScheuer]

If it just slows up the leak to a trickle, we'll keep it instead of installing something else.

[tribologist]

Lol! You probably need to be on Norwegian pages for that spelling. they do the kk. We do ck. ”stuffing box” would be packbox in swedish.

Search images for packbox propelleraxel

Ulf

https://wasayachts.eu/shop/begagnade-pr ... el-nr-176/

[dkirsop]

My boat has the original shaft seal you refer to. My boat is also equipped with the original AD21 diesel engine and the 25mm propeller shaft. The seal is very good, easy to maintain and needs minimal care so long as it is kept properly lubricated. There are a few things to know about to keep the seal working properly.

First, the seal is drip tight. Whenever the boat is launched an air pocket will form in the shaft log at the back of the seal. The seal needs to be in contact with the water to prevent overheating. To remove the air loosen the hose clamps at the back of the seal and wiggle it until water starts to drip from between the hose and the seal then tighten everything up. If the air is not removed the seal will become extremely hot and the lip on the seals will become damaged and leak.

Secondly, apply grease sparingly. The grease will become warm and expand. If there is no room to expand then it will push the front seal out. The body of the unit should only be 1/2 full of grease. The rear seal will not push out if the unit is properly positioned on the shaft log. The rear seal should be about 2-3mm ahead of the shaft log face.

Attached is a detailed drawing of the seal assembly.

shaft seal.jpg

[Bob Noodat]

Thank you so much dkirsop and tribologist. Very good information, plus Swedish language primer. 3000 Krøne is apparently CAN $400. On the face of it that might sound expensive, but one must be grateful that someone still stocks them, I am sure they are not making a fortune by doing so.

I shall store the picture and the invaluable tips, along with the link to the supplier in a file, just in case.

The boat I am interested in has a marinized Kubota V1200B, a 4 cylinder 1.2 litre 22hp engine, said to be half the weight of the AD21.

[DesertAlbin736]

Interesting. Our boat is a 1971, an even earlier hull # than Sea Quill & one hull earlier than Driftless & has an old fashioned drip type bronze stuffing box. Just finished repacking it recently. Runs cool when adjusted for 3 or 4 drops per minute at cruising speed & zero at rest.

[WillieC]

Interesting that Mr. K's pic appears to show the original built in prop remover nut, which exists on my 30mm super deluxe propshaft. And, note, no upper or inner bearing.

[dkirsop]

There is a sleeve bearing in the seal housing even though it is not referenced on the drawing. It might be a babbit bearing. When everything is properly installed the hose casing is in shear and sufficiently stiff to hold the shaft centred in the shaft log which simplifies aligning the engine to the shaft.

[WillieC]

That must be the bearing that Albinmotor lists in their catalog!

Mine, having been swapped over to the PSS style is missing all that. I suspect the log may have been shortened as well. My added beneteau sleeve is serving that same purpose.

[tribologist]

Looking at that drawing makes me think it is the reason why they got away with a long 25mm shaft. That design will add significant damping of the first mode of the shaft. A drippless face seal is adding negative damping if anything.

[honza]

I dare to guess, that the "bearing" is there just to keep the seal rings aligned and centered and that it does not do much for the shaft support.

[dkirsop]

Because the seal assembly sits within 1/16" of the face of the shaft log it is quite stiff when snugged up and does support the shat in the log. At the same time the bearing also prevents the weight of the shaft from resting on the lip of the seals.