alpha drive gear shift problem.

[betty boop]

Looking for advice if anyone has ever adjusted the gear shift cable on an alpha gen 2 leg

the problem,

last week the boat refused to go into reverse, when she eventually selected reverse it
was with above idle revs and need;ess to say she veered off backwards
at 1200/1500 rpm.

IT would seem the cutout switch is not 'cutting out' so I can't select reverse gear
smoothly only forcing.

I understand the principle of the v notch cutout when the remote cable i s pulled
the engine cuts out and gear change is deselected/selected as required, the
switch is set up correctly and works (tested)

What I cant replicate is a forced or difficult gear change on out of water.
I've tried to re adjust the gear shift cable and received different results.
one test reverse cut out worked the next forward cut out only worked.
Fed up on Friday I left her with the cutout appearing to not work in either direction.
I checked it against Betty and both looked and behaved the same.

I then had some work to do on the trim sensors raising and lowering the leg
a lot and today I find the whole system seems to be working correctly with
cutout mech moving as it should and gear shift engaging F & R. as it should.

Am I missing something? I can't see how a set system would give different
results with no interference to its set up. According to the manual the system
although complicated is relatively straight forward minimal movement 2 cable
gear shift with a cam set up to the cut out switch in the middle and throttle cable.

The only thing I haven't done is try to adjust the cable to the gear shift lever as
the book says it is set with adjustment possible. Just wondering if anyone has
gone down this road before on and what adjustments can made if any.

[Ianfs]

Am I missing something?

Yes, just as I was when mine didn't work.

First of all the dog clutch on Mercruisers is an over cut gear which, when under pressure
from water holds the boat in gear. The cut out mechanism is there in order to take the
boat out of gear only and not to put in into gear.

Now the gear shift cable and the throttle cable both work in conjunction with each other,
so if they are not adjusted correctly for some reason, your symptoms will occur.

You cannot test the clutch mechanism properly when the boat is out of the water because
it needs the water pressure to check its correct operation. However you can get the
adjustment right so that when you put her in she will work properly.

This guy is a mate of mine from Aus, hes a top mechanic, however I'm not sure if
this video applies to both Alpha One and Alpha One Gen II but Chris says Alpha
drives so I think they are the same. I hope it helps.

[betty boop]

missing a link there Ian? seems to be a common problem is it me not seeing vids?

[mlines]

Video works fine for me

[betty boop]

Just seen my original post and for help to others - Shifting onto gear seizure, stiffness on
changing gear, constant adjustment of the shift cable ? this problem was found to be
water in the Lower Shift Cable more so Salt deposits causing corrosion and restricted
movement identified as salt or water at the shift plate in engine bay - A new cable
needed and a reseal of the drive obviously as the upper gear housing is removed.

Ive just found out that whilst a gasket failure can cause water in shift cable most
likely (and I missed it ) it will be a failed lower shift shaft seal - whilst the bell housing
is open replace that carrier seal.

[url]http://www.ebay.co.uk/itm/Shift-Shaft-Bushing-Kit-for-Mercruiser-Alpha
-Gen-II-replaces-806036A-1-/260888270424?hash=item3cbe271658:m:m
-HbmeNXjzZjWelBlX0CnUQ[/url]

[url]http://sterndrivetools.com/Replace%20your%20R,%20MR%20or%20
Alpha%20One%20Bell%20Housing%20Shift%20Shaft%20Seal.html[/url]

[Ianfs]

Can I just say, I think I understand what you have studied Ian, but Alpha One Drives and
earlier had a completely different upper shift shaft seal/bushing to Alpha One Gen II's.
They were small and unreliable.

They only sell the newer bushings now and the likely hood of a Gen II leaking is remote,
the newer seal has 3 seals within the brass bush and is much less likely to leak.

Having said all this, as with any leak, imho...if you suspect an issue its always best to
change it out. However if you have a leak into this area, I would suspect the gasket
between the drive and the bell housing at that point....When you tighten the drive
nuts, very often the gasket squeezes out a fraction, it's such a small strip for the
gasket to squash in, it may go one way or the other. A good dollop of
Marine Silicon will stop water intrusion.

CIMG5956.jpg (153.66 KiB) Viewed 14649 times

[betty boop]

very good Ian you are spot on. If I may explain a little - initially my diagnosis was the gasket
but then after completing the job (by pure chance) I read many online reviews on the
Gen 2 seal failing and causing the leak. Yes Gen 1 was unreliable but Gen 2 apparently
are also prone to failure (although having owned one for 12 years now I haven't
personally experienced or heard of this)

funny you should mention silicone on the gasket at that area you highlighted
- when I refitted the drive with black marine gasket sealant + gasket I noticed
the new gasket fitted would not sit between the 2 drive section at the shift
cable chamber . After 3 refit attempts with more gasket sealant added it would
still sit outside the drive. When the trimming knife came out i soon reached
the point of 'Oh Sh@t' and a new gasket was needed. Luckily my spare
(a quality one not a cheap knock off) fitted first time and sealed as it
should AFTER I removed all the gasket sealant. So theory 1 - either gasket
sealant does not work well in that very thin area of contact acting as a
lubricant or cheap gaskets are not worth the saving.

Theory 2 - My belief is the previous gasket also sat proud at this point
(having been 'told' by the dealer it had a full drive service before
being sold) and caused the water ingress but it is unclear how the
water (without exhaust gas pressure) travelled up the shift cable.
The drive has now been tested at low speed and on plane for 45 seconds
(on a river) and the shift cable end & plate is dry having stripped it
down so the only course of action is to leave it for the torbay rally
and check for salt ingress after 4 days of lots of use.

so - from this exercise I've learnt I should read more on faults and
symptoms (if i need to replace the seal the gasket is 1/3 the cost
of the seal (£10 vs £30) so doing that job at the time would have
saved £10).
It also raises the question on gasket seal- those in the profession
hate it and are not advocates of EVER using liquid gaskets.

I will also add (thinking out loud) that I had a the main lower drive
seal fail on Betty but after removing and refitting it was evident
(in case) that the spring seals can be prone to a kind of slippage
and leaking. In betty's case the seal did not leak once it was reseated
under high pressure test over 4 days + but i did replace it. SO it may
be the case that the shaft seal had failed but has reseated now that
I have fiddled with it, i.e. many wiggles.