mercruiser Gen II drive problem

[dutch135]

The boat is a 1993 Crownline with 4.3L LX, I beleive it's a Gen 2 outdrive., the boat has 209 hrs
Have put less than 2 hours on the motor this weekend, but yesterday we launched for an evening fireworks cruise, and noticed a squeel, (at first just thought it
was the normal belt squeel I get every time it starts). Today I am thinking that maybe the squeel was a little different... then put the drive into reverse, and forward as we pull away from the dock, and things didn't act right.
the boat wasn't moving. I raised the lower unit to verify that the prop was in fact still there, and it was, but I was getting no shift sound as I moved in F or R.
At one point, when shifting into F or R, the motor stalled,
and I was thinking it was maybe the ignition, but soon realized I had lost something in the drive. We paddled back to the launch, and loaded the boat on the trailer and I had somebody get in the boat once we were out of the water, and put the lever in F and R... I turned the prop, and when in gear, I would get the normal ratcheting on one direction, but in the other direction, when I turned the prop, I hit resistance, which was normal, but then I realized I could keep turning, without a
huge effort. I had somebody in the boat check the motor
to see if it was turning, but it wasn't... So,,
I think I have a problem in my drive,, possibly gears, upper gears?
Is it possible for a bearing to sieze? then cause something to break? Is there any "coupler" that could be bad? (I think I know the answer to that)
I plan on doing some more investigation tonight, but wondered where to start.
I would feel comfortable taking the lower gearcase off,
and then removing the upper, but I don't think I would
be capable of rebuilding myself.,, seems to intricate for me, and I wouldn't have any special tools needed.
thoughts anyone?:'(

 

[PuddleJumper]

Re: mercruiser Gen II drive problem

When you were able to continue to turn the prop with resistance, did the prop shaft move also? Possibly spun prop hub check before getting in too deep?

 

[hullofalottatrouble]

Re: mercruiser Gen II drive problem

could be your lower unit shift cable gone bad.. the stall may be to the cutoff switch that engages when you go into gear? i may be way off here so interested to hear what others think..

 

[dutch135]

Re: mercruiser Gen II drive problem

I think the shift cable is working ok, because after
we stopped moving, I was able to get a restart and
shift without stalling. And on the trailer, that seems to
work properly.

As far as a spun hub, I seem to be able to hear
things turning inside the unit when I turn it while
In gear,, but I can double check that later to verify.
(although at this point I would give anything to have that be the problem!)

 

[hullofalottatrouble]

Re: mercruiser Gen II drive problem

shift cable could be okay.. but your description of how you

turned the prop, and when in gear, I would get the normal ratcheting on one direction, but in the other direction, when I turned the prop, I hit resistance, which was normal, but then I realized I could keep turning, without a huge effort.

sounds exactly like what happened when my cable went bad.. it just couldnt hold the drive in gear so i could force it to turn as you did.. replaced the cable and all is well.. also turning the prop if it isnt fully engaged is really nothing more than turning it in neutral so you wouldnt notice the engine turning over at all..

you may also find that you can shift on the trailer on muffs and it will appear to work just fine.. but once in the water under load it doesnt hold it in gear at all.. all things that were signs of a bad cable on my boat..

just dont want you to jump to more complicated problems like coupler etc if it really is just a more straight forward cable replacement.

 

[tommays]

Re: mercruiser Gen II drive problem

Start simple and be sure the prop is GOOD

I would remove the upper vent plug and be sure the oil is full and then drain the oil and look for metal or water


IT could be a the motor couppler or other things BUT if the drive is not turning you dont have a water pump and would overheat very fast

Tommays

 

[dutch135]

Re: mercruiser Gen II drive problem

ok,
lunchtime update,,
i had a few minutes to look at it on lunch..
took the top off the upper gearcase,
and had it in gear, and turned the prop.
Everything I can see from there seems to be
turning fine,,, the gear looks like new,, and
the oil looked new, (changed last fall)

so, if that's the case,, do I pull off the whole
lower unit, and see what I see with the driveshaft?

What could go wrong there? Could a failed gimble
bearing cause something to break?

 

[hullofalottatrouble]

Re: mercruiser Gen II drive problem

pull the whole drive off and check the gimble bearing and coupler and for water in belows and u-joints etc and you will be able to know if its a failed bearing or something else.. drain the gear lube and check for any water in the lube or metal chunks and come out..

if they all appear fine.. grease everything up as just a general maintenance step..

then while you have the drive off change the lower unit shift cable.. and put it back on and see if that fixes it for you..

 

[dutch135]

Re: mercruiser Gen II drive problem

coupler question:
Is that visible inside the engine compartment?
(standing on my head with mirrors)

From what I read, this seems to act just like
the hub on a prop.. can "spin" and then
need to be replaced.

I did have a larger than recommended load this
weekend, and while pulling my son on his wakeboard he
would feel this need to try to stop my boat with his
board causing my boat to work quite hard with the
other 6 people in it.. (yes. i was overloaded)
is it possible that something like this could cause this
coupler to spin or go bad?

why can't they use slip clutches like we use for
farm machinery!!

 

[hullofalottatrouble]

Re: mercruiser Gen II drive problem

dutch,

you wouldnt be able to see the splines in the coupler without pulling the drive shaft out.. so if you want to check into all this you will need to pull your drive and you can then inspect everything.. and while you are at it replace the lower unit shift cable..

 

[dutch135]

Re: mercruiser Gen II drive problem

ok,
i won't bug you guys any more until i do a little
more inspection, working late tonight,
and the grass needs mowing too!

hopefully by the weekend i can get an hour or 2 to look into this and see if i can find what happened...

thanks for the info so far...

 

[Fishermark]

Re: mercruiser Gen II drive problem

You already did what I would suggest first - which is taking the top off of the outdrive. Since that looks good, I would suspect either a coupler or bad prop. Does it overheat and / or pump any water out? If the coupler is spun, the water pump will not be turning, so the engine will overheat very quickly. If the prop hub is spun, the water pump will still turn, so the engine doesn't overheat.. you just don't get anywhere! You need to pull the outdrive in order to check the coupler.

 

[dutch135]

Re: mercruiser Gen II drive problem

had 5 mins tonight to look a little deeper,
and low and behold, when the prop is turned
while in gear, the shaft turns right behind the motor
and tells me the coupler is gone.
so, now i have to pull the outdrive and motor to fix it,
and everybody talks about motor alignment...
my motor has "fluid engine mounts", and it looks like
only 2 of them, one on each side. so, how does one
align the motor to make sure that this failure doesn't
happen again?
and at 200 hrs, what would be the cause? there isn't any rot in the boat, everything is still solid. could the load on the
drive, and torque needed with that loaded boat have done this? I guess once i get the drive off, and check alignment,
I will know more.
thanks for the info to date,, but I am thankful my outdrive
is ok, and even though this is a fairly major repair, it
could be worse.
I'll update as I know more

 

[Bt Doctur]

Re: mercruiser Gen II drive problem

you wont be able to check anything untill the coupler has been replaced,replacing the rear mounts as a precautioary measure is not a bad idea.the failure may have been caused by improper alignment from day 1.front mount nuts may have been loose and caused alignment to shift enough to tear out the coupler.a few good strikes dosent help the life of the coupler either not to mention the parts in the outdrive.you running SS or Alum . prop?

 

[dutch135]

Re: mercruiser Gen II drive problem

From what I can see, this engine only has 2 mounts,
1 on each side... here is the pic:

is there a rear mount?
I see a flywheel cover, but couldn't see any mount
back there.

 

[hullofalottatrouble]

Re: mercruiser Gen II drive problem

dutch sorry to hear its a coupler.. check the alignment when you get the drive off and you might find your cause right there.. i stand corrected by don in his post below.. good thing he is around to keep my in line..

im guessing that your flywheel cover will have rear mounting bolts on it that attach to the transom plate.. dig around back there and you might find em.. at least thats the setup i have on my v8..

 

[Don S]

Re: mercruiser Gen II drive problem

Like BT Doc said, you can't check alignment on a bad coupler. It wouldn't tell you anything. If the rubber is spun, it's twisted all out of position, if the splines are spun out there is nothing there for the alignment bar to touch.
Usually if the coupler is bad, the splines on the drive are also worn down. Installing a bad shaft in a new coupler will assure a future coupling failure.

 

[dutch135]

Re: mercruiser Gen II drive problem

ok thanks,
i'll dig a little more, and I am in the process
of finding a little more qualified help to do
the job. I find it odd that mercruiser would
put this motor on "fluid mounts", that must
allow some flex, yet the alignment at the coupler is so critical.

Is it possible that with the load I had in the boat,
and the wakeboarder behind, that there was just
too much torque and it failed due to that?

and yes,, will check splines on shaft and replace if needed for sure. I see 2 different parts in the diagrams,
with 2 different prices, and I am assuming the difference is one comes with the shaft.

and yes, running aluminum prop, with no strikes
that I know of,, (minor scrape last year, but
hardly a nick on the prop)

thanks again for the input

hopefully soon I will have some "output"

d

 

[dutch135]

Re: mercruiser Gen II drive problem

The job was done by the weekend, local mechanic
came by and did it in about 10 hrs... I felt that was
fair. Definately a lubriction ( or lack of) problem. It
looks like the prior owner had never removed outdrive to lube the splines... and the coupler finally gave out.
The alignment did look good, and up on reinstalling the
motor the alignment was dead on, (mechanic has the
proper tool). He double checked several times before
installing the outdrive, with fresh grease at U joints and gimball. Everything looks great, and we had a chance to get out on the water yesterday, and no problems.
Thanks for the help...
happy boating

8)