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

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

On Sat, 14 Feb 2004 20:05:57 GMT, Jim Kelly wrote:

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.

Ah - makes sense. So the whole drive train, engine/tranny/shaft/prop
are at some sort of angle then?

Later,

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

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

Yes, the transmission is bolted to a bell housing on the engine so that it
sits at the same angle as the engine. The prop shaft also assumes this angle
since it is direct coupled to the transmission. This is what is referred to
as a "straight inboard". On many newer boats of this size, the engine is
mounted backward with the front of the engine close to the transom. A V-drive
is then used to connect the engine to the prop shaft. On this type of
installation, the engine is not angled as in the straight application since
the prop shaft angle is accommodated by the angled "V" drive design.

Short Wave Sportfishing wrote:

On Sat, 14 Feb 2004 20:05:57 GMT, Jim Kelly wrote:

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.

Ah - makes sense. So the whole drive train, engine/tranny/shaft/prop
are at some sort of angle then?

Later,

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

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