I've had my 1978 Trojan 26 for three seasons now, and can't for the life of
me decide for sure whether the transmission has always done this or not. My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet Drive,
original with the boat, to my knowledge.

When put into gear, there is a slight pause, a fraction of a second only,
but easily visible that the prop tranny/shaft does not start turning
immediately - then it catches and away it goes. (Idling just above 600 rpm
indicated.) It does so with a very soft audible clunk, and I seem to
remember it being noiseless when "new" (to me).

I have shifted it into gear at above idle speed, very infrequently, count on
one hand, etc., because I'm kind of clumsy. Other than that, I can't think
of anything that might be considered abusive.

It is still so much smoother than the Bravo II I/O I used to own, which
itself was so much smoother than the Alpha 1 before that. Passengers have
never noticed or commented - it's quite a subtle clunk. I think I may just
be listening too hard.

What is normal behaviour for these transmissions? Thanks.

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

On Sat, 14 Feb 2004 06:16:23 -0500, "Charles T. Low"
wrote:

I've had my 1978 Trojan 26 for three seasons now, and can't for the life of
me decide for sure whether the transmission has always done this or not. My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet Drive,
original with the boat, to my knowledge.

When put into gear, there is a slight pause, a fraction of a second only,
but easily visible that the prop tranny/shaft does not start turning
immediately - then it catches and away it goes. (Idling just above 600 rpm
indicated.) It does so with a very soft audible clunk, and I seem to
remember it being noiseless when "new" (to me).

I have shifted it into gear at above idle speed, very infrequently, count on
one hand, etc., because I'm kind of clumsy. Other than that, I can't think
of anything that might be considered abusive.

It is still so much smoother than the Bravo II I/O I used to own, which
itself was so much smoother than the Alpha 1 before that. Passengers have
never noticed or commented - it's quite a subtle clunk. I think I may just
be listening too hard.

What is normal behaviour for these transmissions? Thanks.

It sounds like normal wear - the "clunk" is probably gear lash and/or
a bearing or shaft just slightly out of spec. It's close to thirty
years of service - that's pretty good on an inboard transmission I
would think.

I wouldn't worry about it until it gets to being a "thunk" instead of
a "clunk" or you start hearing gear noises while underway. At that
point, it would be worth looking at.

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern

Charles T. Low wrote:
I've had my 1978 Trojan 26 for three seasons now, and can't for the life of
me decide for sure whether the transmission has always done this or not. My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet Drive,
original with the boat, to my knowledge.

When put into gear, there is a slight pause, a fraction of a second only,
but easily visible that the prop tranny/shaft does not start turning
immediately - then it catches and away it goes. (Idling just above 600 rpm
indicated.) It does so with a very soft audible clunk, and I seem to
remember it being noiseless when "new" (to me).

I have shifted it into gear at above idle speed, very infrequently, count on
one hand, etc., because I'm kind of clumsy. Other than that, I can't think
of anything that might be considered abusive.

It is still so much smoother than the Bravo II I/O I used to own, which
itself was so much smoother than the Alpha 1 before that. Passengers have
never noticed or commented - it's quite a subtle clunk. I think I may just
be listening too hard.

What is normal behaviour for these transmissions? Thanks.

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====


The "delay" is normal & deliberate via a bleed hole before delivering
full pressure to the clutches (not unlike the car, has a delay when you
select drive), if the mechanic is happy & you have confidence in him/her
then that's the answer.

The "clunk" might be the shaft bush/bearings, if they're a tad worn the
shaft moves to one side each time, again not really a worry.

K

On Sat, 14 Feb 2004 06:16:23 -0500, "Charles T. Low"
wrote:

I've had my 1978 Trojan 26 for three seasons now, and can't for the life of
me decide for sure whether the transmission has always done this or not. My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet Drive,
original with the boat, to my knowledge.

~~ snippage happens ~~

It just occured to me - does the drive train have U-joints? If so,
then that's the most likely cluprit.

Good luck.

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern

Tom,

As others have already explained, this is a straight-shaft inboard setup,
pretty standard, I think, and it is not horizontal. You can see a photo at
www.ctlow.ca/Trojan26/Rudder2001.JPG, from my Ksenia page (address below).
No U-joints, and no "shock absorbers" - the shock is absorbed by the water!

I think it would be more efficient if it were horizontal, and on some
displacement hulls (a few) it is, but on a planing hull I think it just has
to angle down. Building a casing below the hull to contain a CV joint which
would then allow the shaft to run horizontally would not be
"hydrodynamically" efficient either, I don't think - might as well have an
I/O - pros and cons! I do depend heavily on trim tabs to maintain attitude
when on plane. ("Slow" plane, which is all this boat does!)

The cutlass bearing referred to elsewhere is in the housing at the bottom of
the strut in the photo referred to above. The prop shaft is stabilized by it
and by the passage through the hull and then at the transmission. Apparently
very long shafts require extra supports, but for most of us that's a typical
arrangement. If the shaft were misaligned with the tranny, or just not
straight enough, then that would cause vibration and premature wear of all
sorts of things (I guess), but not the behaviour I'm describing. At least,
not directly.

I have, by the way, checked the prop, by hand, but it seems absolutely
solid.

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

"Short Wave Sportfishing" wrote in message
...

It just occured to me - does the drive train have U-joints? If so,
then that's the most likely cluprit.

Good luck.

Later,

Tom
S. Woodstock, CT

On Sun, 15 Feb 2004 16:53:37 -0500, "Charles T. Low"
wrote:

Tom,

As others have already explained, this is a straight-shaft inboard setup,
pretty standard, I think, and it is not horizontal. You can see a photo at
www.ctlow.ca/Trojan26/Rudder2001.JPG, from my Ksenia page (address below).
No U-joints, and no "shock absorbers" - the shock is absorbed by the water!

Twelve boats in my life, all outboards. I'm seriously thinking about
converting the '68 Chris*Craft Corsair to an outboard - I did rebuild
a "stringer" type drive and I have two Buick V-6s, one of which has
been rebuilt, but I'm not at all comfortable with that setup.

All of which has nothing to do with your drive system. :)

Well, as long as you are happy with it, that's all that's necessary.

Good luck.

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern

Any clunking would be play somewhere in the drive train. Most transmissions
do not 'engage' or disengage gears, the gears are always engaged and another
device connects or disconnects the gears from the shafts. In your case a
fluid operated clutch. Usually these clutches weaken and slip with age.
Rarely a malfunction can cause the fluid pressure to be too high or the
clutch to grab but that is very unusual. The application of power to the
rest of the drive train will take up slack anywhere there is some. Some
slack is normal but it would not hurt to take a closer look at all the
pieces of the drive train from the engine through to the prop. A u-joint,
loose prop, loose engine coupler, will make a clunk. It is hard to check
the transmission it's self for play because it will not engage unless it has
power to it. The rest of the drive train you can often check with the
engine off by grabbing stuff and trying to turn it against it's self.

"Charles T. Low" wrote in message
. ..
I've had my 1978 Trojan 26 for three seasons now, and can't for the life
of
me decide for sure whether the transmission has always done this or not.
My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear
to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet
Drive,
original with the boat, to my knowledge.

When put into gear, there is a slight pause, a fraction of a second only,
but easily visible that the prop tranny/shaft does not start turning
immediately - then it catches and away it goes. (Idling just above 600 rpm
indicated.) It does so with a very soft audible clunk, and I seem to
remember it being noiseless when "new" (to me).

I have shifted it into gear at above idle speed, very infrequently, count
on
one hand, etc., because I'm kind of clumsy. Other than that, I can't think
of anything that might be considered abusive.

It is still so much smoother than the Bravo II I/O I used to own, which
itself was so much smoother than the Alpha 1 before that. Passengers have
never noticed or commented - it's quite a subtle clunk. I think I may just
be listening too hard.

What is normal behaviour for these transmissions? Thanks.

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

There are no U-joints, bleed holes or built in delays.

When you move the selector to forward or reverse, the spool valve directs the
fluid to the proper clutch. There should be at least 120 PSI present at the
spool valve in all selector positions. The internal pump is actually capable of
much higher pressure but it is regulated by a relief valve built into the end of
the spool valve. The relief valve directs fluid to the heat exchanger. There
are test ports for checking the pressure. Remove the 3/8 plug on the top of the
case next to the port leading out to the heat exchanger. Warm and idling you
should read at least 120 PSI in all selector positions.

To check reverse pressure, there is a smaller plug either next to the 3/8 plug
or on the front adapter on the top of the case depending on the vintage (some
models have both plugs in which case you can use either). Warm and idling in
reverse, you should again read a minimum of 120 PSI. This verifies that the
reverse clutches in the front of the transmission are receiving full apply
pressure.

There is no separate test port for forward apply pressure since the hydraulic
circuit for forward is through the center of the shafts and not the case as it
is in reverse. If you have the specified pressure at the 3/8 test port while in
forward, it is pretty safe to assume that the forward clutches are receiving
full apply pressure due to the design of the circuit.

"Charles T. Low" wrote:

I've had my 1978 Trojan 26 for three seasons now, and can't for the life of
me decide for sure whether the transmission has always done this or not. My
mechanic thinks it's OK. The AT lubricant is full and looks crystal clear to
the naked eye, and I do change it (rarely). It's a Borg-Warner Velvet Drive,
original with the boat, to my knowledge.

When put into gear, there is a slight pause, a fraction of a second only,
but easily visible that the prop tranny/shaft does not start turning
immediately - then it catches and away it goes. (Idling just above 600 rpm
indicated.) It does so with a very soft audible clunk, and I seem to
remember it being noiseless when "new" (to me).

I have shifted it into gear at above idle speed, very infrequently, count on
one hand, etc., because I'm kind of clumsy. Other than that, I can't think
of anything that might be considered abusive.

It is still so much smoother than the Bravo II I/O I used to own, which
itself was so much smoother than the Alpha 1 before that. Passengers have
never noticed or commented - it's quite a subtle clunk. I think I may just
be listening too hard.

What is normal behaviour for these transmissions? Thanks.

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

On Sat, 14 Feb 2004 16:41:25 GMT, Jim Kelly wrote:

There are no U-joints

~ snippage ~

Along the propeller shaft? I mean, I have never owned an inboard or
an i/o (other than the Chris*Craft I'm salvaging) so I don't know.

It would seem to me that a direct connection to the engine/tranny
combination without having a U-joint of some sort to help absorb
vibration wouldn't be a good design.

How else with the type of transmission you described, would you
develop a clunk? Prop loose maybe?

Just trying to learn. ;)

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern

The transmission is direct coupled to the prop shaft. The prop shaft is
supported on the other end by a cutlass bearing that employs a rubber
insert. Although the rubber insert will absorb some vibration and very
minor misalignment, it is important to verify alignment at the coupling
on the transmission. This is done by taking out the bolts holding the
two coupling halves together, separating the halves slightly and checking
alignment with a feeler gauge. This must be done with the boat in the
water.

A clunk could come from several places. A loose prop or worn prop key, a
worn cutlass bearing, a loose coupling, or the transmission itself. I
think the first thing you should do is try and find the source of the
clunk. This would best be done with the boat out of the water. Have
someone move it in and out of gear while you check each area. Only put
the transmission in gear momentarily when the boat is out ot the water
and do not run above idle. The cutlass bearing is lubricated by the
water that surrounds it and will not be lubricated when the boat is out
of the water.

I hope this helps.

Short Wave Sportfishing wrote:

On Sat, 14 Feb 2004 16:41:25 GMT, Jim Kelly wrote:

There are no U-joints

~ snippage ~

Along the propeller shaft? I mean, I have never owned an inboard or
an i/o (other than the Chris*Craft I'm salvaging) so I don't know.

It would seem to me that a direct connection to the engine/tranny
combination without having a U-joint of some sort to help absorb
vibration wouldn't be a good design.

How else with the type of transmission you described, would you
develop a clunk? Prop loose maybe?

Just trying to learn. ;)

Later,

Tom
S. Woodstock, CT
----------

"Fisherman are born honest, but they get
over it." - Ed Zern