1989 Volvo duoprop model 290 with a 5.0L engine. When shifting into forward,
there is a 2 or 3 second 'lag' before the outdrive engages. It's not the shift
linkage, I checked it and then the marina confirmed it was adjusted correctly.
It also isn't 'cable stretch' as some friends have suggested.

Marina thinks that the 'clutch' in the outdrive is wearing out and will need a
$1,000 rebuild. I ran the outdrive for the remainder of the season (about 6
weeks) as is but now I need to make a decision.

Anyone have any advice or experience with this problem?

Thanks.

Wklkj wrote:
1989 Volvo duoprop model 290 with a 5.0L engine. When shifting into forward,
there is a 2 or 3 second 'lag' before the outdrive engages. It's not the shift
linkage, I checked it and then the marina confirmed it was adjusted correctly.
It also isn't 'cable stretch' as some friends have suggested.

Marina thinks that the 'clutch' in the outdrive is wearing out and will need a
$1,000 rebuild. I ran the outdrive for the remainder of the season (about 6
weeks) as is but now I need to make a decision.

Anyone have any advice or experience with this problem?

Thanks.

Assuming the linkage etc is all Ok as you suggest;

The drive is transmitted by two cones coming together one is on a very
course thread on the shaft, so when you put it in gear all that happens
is the shift fork gives it a nudge in the right direct, after that the
cove spins along the shaft till it collides with it's partner & starts
transmitting power.

Once it's got load on it they stay engaged because the thread on the
shaft is pushing the two cones together, the more power the tighter the
engagement.

If you have seen a set of synchromesh cones from an old manual car
gearbox they look exactly like that only much bigger & these cones don't
just get the two gears to the same speed before splines slide into
slots, they are the "only" engagement. If you hit something they should
have some slip but gees louise not likely:-)

The common problems are;
(i) Like car synchromesh cones they have fine grooves machined into the
mating surfaces to disburse oil, once they wear off & the cones are just
smooth it's harder to get them to initially engage, however once the
cones get power through them, driven by the threaded shaft they will lock.

(ii) The shift fingers run in a groove which has tiny lumps deliberately
put into the walls, so as you shift it gives the sliding cone some
shocks to encourage it to start sliding along the shaft's thread.

(iii) Check to see it's got the right oil!!! Lots of people put a
different oil in there but it doesn't allow the cones to slide into
engagement as easily. Most of them just use engine oil but check your
manual & make sure someone hasn't put special marine "gear oil" in
there, if so your problems might be as simple as putting the correct oil
in it.

You can get the top off the leg & access the shift cones etc pretty
easily so it's not a big job to have it properly checked, alas the
proper fix might be expensive.


K