drive shaft

[wombil]

Hi Guys,My first time here.
I have a Mariner 4 H.P. 4 stroke.
I have just installed a new impeller and no problems with that.
My trouble is getting the drive shaft back into the crank shaft.I have done this many times before on other motors and usually with a few wobbles and wriggles it just slides in and you can connect up.
I can get within 2 inches of the bottom end closing up but the end of the driveshaft is coming up against something solid.Feels like the end of the crank
but maybe it's not quite there yet.Cant get the spline to mesh with the crank so it's not lining up correctly.
I have been prodding this for a couple of hours now and still no go.
Is there anything that can get in the way of the shaft and stop it lining upor is there some trick with these motors that I don't know about.
Any advice greatly appreciated.
Wombil.

 

[wombil]

Re: drive shaft

Hello again,
still going on this and considering grinding a bigger taper or lead in on the shaft or even taking the power head off.
Any ideas about this?
Thanks for looking.

 

[j_martin]

Re: drive shaft

I wouldn't be grinding on a drive shaft unless you're made of money and want to waste it.

You need the maintenance manual for this engine, available at your mercury dealer. If there's a trick to the assembly, it'll be in the manual. An example I know of is that a gob of grease on the top of a V6 driveshaft will prevent proper assembly. It's in the book.

hope it helps
John

 

[wombil]

Re: drive shaft

'Lo John,
Got the manual from the local library but only for 2 stroke engines but the lower unit seems to be the same.The instructions are the same as what I have been doing.The shaft seems to enter a tube or perhaps an O ring at the top of the leg and then just bangs up against the crankshaft end.I can see up the leg and everything seems to be clear and open to the crankshaft spline.I am beginning to think that the power head has been installed a bit off centre and the driveshaft is hitting the edge of the spline hole.This seems highly unlikely but in these days when things are built down to a price and not up to a standard who knows?Any thoughts about this?
I have tried all the gear combinations and it is definately not a grease problem.
I may take the powerhead off,install the leg and then put the powerhead back on.
Lucky we are not in a hurry for this motor

 

[Silvertip]

Re: drive shaft

Remove the spark plugs and have someone rotate the engine by hand while you install the lower unit. It may also be possible you are not getting the water tube lined up as well. It also works better if the engine is oriented full vertical rather than tilted.

 

[wombil]

Re: drive shaft

Tried at full vertical but will give it some more tries.The water tube is centered on the delivery tube ok but the leg will not go up far enough for it to enter the delivery tube.The top end of the lower gear shift rod also has to go out of a hole in the top of the casing but hasn't got near that either.
Thanks for the suggestions.

 

[wombil]

Re: drive shaft

Fixed The Fing,
Took The Motor Off And Put It Together Backwards,no Trouble.
Never Had To Do This Before.
I Think The Gear Lever Setup Was Stopping The Driveshaft Lining Up With The Crankshaft Tube.something Is Skewwhif In The Leg.
Would Like To Know If Anyone Else Has Had This Problem.
Would Also Like To Say Some Very Rude Things About This Job But This Is A Nice Place So I'll Let That Go.
Thanks For All Your Interest,
Wombil