Kanzaki transmission problems
Desert_Mariner
I'm new to the group today. Thanks for letting me in. I just bought
a 2003 Beneteau 411 Special Edition in late August. It is berthed at
Marina Del Rey, CA. On seatrial, we noticed a high pitched noise in
the drive train that begins around 1400rpm, peaks at 1600 and dies off
at 1800. The noise only occurs when the boat is lightly loaded
underway "at speed". It will not occur when the transmission is under
heavy load as when starting from a stopped position. The broker
thought the noise might be coming from the cutlass bearing. The
surveyor said "maybe".
At haulout, the surveyor found a bad cutlass bearing. The owner
agreed to replace it. I insisted in a later email to the broker that
while the noise may have been coming from the cutlass bearing, the
noise had to be corrected as a condition of purchase. I live in
Arizona. The boat is in California. I relied on the broker's
assurance that the noise was fixed. Well, as you can imagine, the
noise is still there.
A mechanic recommended by the broker inspected the drive train last
week and determined that the transmission is shot. It is a Kanzaki
Tuff Torq Model KBW20-1. It is coupled to a 56HP Yanmar. The Yanmar
shows only 420 hours on the meter. The mechanic drew a small amount
of fluid from the transmission. The fluid is black, opaque and smells
of carbon; definite evidence of overheating and probably burnt
clutches. I'm guessing the noise itself is coming from a burnt
bearing. Additionally, the prop shaft turns slowly in reverse when
the transmission is in neutral. I'm working now to try to get the
previous owner to ante up and fix this problem, but I'm not holding
out a lot of hope.
So here are my questions.
Has anyone had a similar experience with this transmission? It seems
like a very low number hours for the transmission to have gone bad.
There is no evidence of a leak, either current of past.
Does anyone have any recommendation or experience, as an owner, with
rebuilding these?
Can I buy a rebuilt transmission from a supplier like I would buy a
rebuilt carb from an auto supply store and then send back the core?
How much should this cost to rebuild this transmission?
What should be the customary warranty period and terms for a rebuilt
marine transmission?
Does anyone have a recommendation for a certified and reputable
rebuilder in Southern California?
Thanks for the help.
Dan Berkey
S/V Corvette
Beneteau 411 SE
Alvis
We were Yanmar dealers in Australia for many years, and I know the KBW
20 well.
We almost invariably found that the root cause was mis adjustment of
the remote controls. The owners handbook is very specific about
checking this regularly.
Your observation of slow rotation in neutral also suggests this.
The burnt oil tells you there has been clutch slipping under load.
Unfortunately you will probably need to have it overhauled, but it is
worth trying a flush out and new oil (ATF type A) and MAKE SURE THE
REMOTE CONTROL ADJUSTMENT IS PERFECT!
The fact that the noise goes when you are at full thrust is
encouraging. It means the clutch plates are not totally worn.
You can still engage ahead and astern, so the fork mechanism can't be
too badly worn either. That is the other thing that happens when there
is mis-adjustment.
There should be no pressure on the gearbox control lever except during
a change. ie in neutral or ahead or astern, once the change has been
made, both the gearbox lever and the remote control lever in the
cockpit should be sitting happily in their detents, without applying
pressure on each other.
It is simple to check.
The cable is usually connected to the gearbox by a ball joint that can
be quickly disconnected. If not, it will be a clevis and pin, which is
almost as easy to disconnect. Separate this connection.
Firstly check the neutral adjustment.
Put the remote control in the cockpit in the neutral position. (There
should be a distinct 'notch' feel when it is in neutral.)
Similarly move the lever on the gearbox by hand and make sure it is in
the neutral detent.
At this point the cable should be positioned so that it slips on and
off the ball (or the pin slips in the clevis) without having to move
the lever at all.
Now check that the same is true in ahead and astern. If these don't
line up as well, the travel is not correct and will need to be
adjusted by choosing a different hole on the lever at one end or the
other. An old and worn Morse cable can also cause trouble. If in
doubt, change it. A new one will be smoother and easier to move as
well. If you need to do this or change the lever positions, it is
probably worth getting an experienced mechanic to do it.
The Kanzaki gearboxes are unusual in that they use the torque of the
engine to create the engagement forces for the clutch plates, so it is
better to make the engagement positive and quick. This results in a
distinct 'clunk' as it engages which sounds a bit disconcerting. It is
actually not good to ease it into gear gently as you would
instinctively try to do.
This actual mechanism is a set of balls running up ramps between two
plates. In time, the balls can wear a groove at a particular spot, and
once this gets too deep it stops the process.
Good luck, and I hope you have caught this in time to avoid the major
overhaul.
Stuart
Larry Cohan
> We were Yanmar dealers in Australia for many years, and I know the KBW
> 20 well. We almost invariably found that the root cause was mis adjustment of
Stuart, that was a really good posting. Even those of us without those
symptoms learned a lot from your tutorial. Thanks.
Larry
Desert_Mariner
Thanks so much for your detailed reply. Your post now has an honored
place in my maintenance log as part of my annual check.
As an update to all who helped me through this ordeal, last week
Marcus P. from the Botswain's Locker in Costa Mesa, CA inspected and
serviced my transmission. Botswain's Locker has been in the marine
power business since the 1930s and came highly recommended from
several sources. To my great relief, Marcus informed me there is
nothing wrong with the transmission and it does not need a rebuild.
He believes the transmission has never been serviced since new (440
hrs), but that the fluid was just very dirty and the transmission is
operating normally. The noise he traced to the dripless packing
gland. This Beneteau uses a Volvo gland with saltwater cooling/
lubrication coming from a through-hull located next to the gland.
Marcus was very strong in his opinion that this setup is inadequate
and prone to clogs and failures. He recommended changing the
saltwater source from the through-hull to a port off the engine raw
water system. He performed the modification, serviced the
transmission and checked the engine-propshaft alignment. Problem
fixed. YooHoo!!! Although it was expensive to use this company (I
had to pay the standard rates for the 4 hour round trip travel time
from Costa Mesa to Marina Del Rey), it was worth it. Thanks to
Botswain's Locker and Marcus! It always pays to use the best.
Dan
B411 SE "Corvette"
Tempe, Arizona