Re: [Amel Yacht Owners] Prop shaft bearing
I received this from ian & Judy Jenkins.toggle quoted messageShow quoted text
Amel Super Maramu #376 Kimberlite
HOW TO STRIP DOWN PROPELLER AND STERN GLAND
You will need a 24mm spanner or ratchet in addition to usual tools plus the
following allen keys 3mm, 4mm, 1/8th and 9/64ths.
1. Undo the 3 nylon bolts holding on the red nose. This reveals the
nut secured by an allen key. Round the side of the allen key may need
cleaning. The allen key needs quite a lot of pressure to shift it.
2. Once the allen key is removed, the big central nut will also take a
lot of pressure to undo. You need a block of wood about 12” square and 2”
thick. This rests between one of the prop blades and the horizontal surface
of the keel below to keep the shaft still.
3. Having loosened the big nut, but before it is removed, put in place
the 3-bolt remover. Each of the 3 bolts goes home. Then put a big spanner
on the centre bolt and assist by ‘tapping-in’ the centre bolt lightly with a
hammer. The bolt takes a lot of shifting, about ¼ of a turn per effort,
tapping also on the shaft between the prop and the prop-cutter (quite hard).
4. When the big bolt turns freely, unscrew the 3-bolt remover, remove
the centre nut and the whole prop.
5. Remove the collar and clean off the outside of the cutter blade.
6. Tap out the key on the stainless steel shaft – tap fore and aft and
it will come.
7. Undo the allen keys on the cutter. NB at least one of these is a
non metric key! ALSO when holding the shaft do so with a rag or glove as
the key-housing is very sharp.
8. Loosen the large nut with a V in it - which is below the stainless
steel shaft. Before removing it put a wide funnel, hose and container under
it. Be prepared for the oil to spurt out. It will take about an hour to
drain. It is not necessary to open the oil reservoir inside the boat.
9. Having removed this large nut and drained the oil, dig out the
narrow seal (against which the inboard end of the nut rests) with a
10. To put BACK this big nut, check the O ring on it, put silicon on it
plus a new seal to replace the seal taken out under 9. Replace the seal on
the nut shaft with silicon on the boat-side of the seal. When the nut is
tightened up the V should be vertical.
11. To extract the ‘wearing out ring’ (which I refer to as the bronze
bearing), undo the 2 allen keys and use a screwdriver to lever against the
allen key or tap out the bronze bearing using a hammer and chisel - the
chisel pointing obliquely aft.
12. Once the bronze bearing is out, take a big screw-driver and dig out
the 3 rubber seals.
13. With a small blade clean the surface of the in situ (female) part of
the bearing. Also with sandpaper clean the aft-part of the internal surface
having sealed inboard with some tissue (the seals sit slightly in from the
aft edge of the in situ bearing so there can be a build-up of calcium here).
After cleaning remove tissue!
14. Before replacing bronze bearing with its 3 seals, you need to make
sure that the O ring on the inside of the new bronze bearing will fit
properly. To do so, push the new bronze bearing home without fitting the
seals. It should go with a hard push from your hands. If it doesn’t, try a
different O ring, as they are not all absolutely identical.
15. Once you are happy with the O ring fit, fill each rubber seal with
grease plus a very small amount on the edge of the in situ bearing to assist
entry. Use the old bronze bearing to push in the first, subsequently the
second and subsequently the third (i.e. do not put all 3 in at the same
time) NB The first 2 seals have the hollow section facing forward, the
3rd has the hollow section facing aft. ALSO it helps in
tapping home the old bronze bearing to use a pipe with a greater diameter
than the shaft, one end of which you can rest against the outer face of the
old bronze bearing and the other end of which you can tap with a hammer.
16. Having tapped home the 3 seals so that the 3rd seal is about 10mm
inset, remove the old bronze bearing and push in the new bearing so that it
is hard up against the outboard seal. THEN ease the bronze bearing aft 2mm
so that it is not actually touching the seal. This will leave the 2 allen
keys on the bronze bearing about 2 to 3 mm aft of the in situ bearing and
the widest part of the bronze bearing will be about 2mm inside the in situ
bearing. Tighten these allen keys.
17. Replace the thin rubber ring on the shaft ahead of the stripper.
18. Fit a new anode on the stripper. When reassembled this anode fits
inside the V on the big nut. Tighten the two pairs of allen keys to secure
the stripper to the shaft.
19. Replace the rubber ring aft of the stripper.
20. Replace the key in the stainless steel shaft.
21. Clean the inside of the prop and put the prop back on the shaft,
lining up the slot on the prop with the key. Tighten up the 24mm nut really
tight, to fasten the prop to the shaft and replace the allen key against a
flat side of the nut using Loctite.
22. Replace the nylon nose without greasing the 3 nylon nuts.
23. Take this opportunity to re-grease the prop through the allen key
holes on each blade and hub. These do not need Loctite on replacement.
24. Refill the leg with 15w40 oil through the reservoir – it will take 8
to 9 litres.
25. When draining the BOW THRUSTER TUBE capture the oil in a transparent
container to see if there is any water in it. If there is, change the seal
between the prop and the leg.
[mailto:firstname.lastname@example.org] On Behalf Of minaxi53
Sent: Thursday, April 13, 2006 3:34 PM
Subject: [Amel Yacht Owners] Prop shaft bearing
Can anyone give a detailed description as how the prop bearings are
pulled and replaced. My boatyard mechanic is reluctant to do this as
he has not worked on Amels Drive before.
Vito, I believe you did this a while ago? How are things going? I see
you made it to the other side so far, drop me an email with your
Thanks for any info
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