drive shaft hard to turn

[kazek]

well,its 1975 merc 850 lower unit.after complete water pump change (really tight fit)i cant turn drive shaft by hand.it gives whith vice grips on splines.i was expecting it would have some resistance given that seals are new,but not that much.what did i do wrong?i am pretty sure parts were right.
i could not push in lower housing by hand so used uper housing and brought it down with pumps nuts.old housind was hard to come out so i figured that new one has to have tight fit also.any ideas on that?

 

[merc850]

Re: drive shaft hard to turn

It can be hard to turn because the dry friction of the waterpump impeller in the housing, if you want to check for that cause put the LU in water and see if it turns better.

 

[SaabFAN]

Re: drive shaft hard to turn

Did you align the impeller correctly? If the flukes of the impeller are bent the wrong way, the pump will not work properly and the restistance is greatly increased. Made this mistake too when i change the impeller of my outboard the first time.
To prevent corrosion and wear, i used massive amounts of grease on the driveshaft, the impeller and every point i could reach where metal comes into contact with metal. I practically filled the pump with grease so that it squeezed out everywhere.
From my perception, the driveshaft became easier to turn after the replacement of the impeller and excessively greasing every part.

 

[kazek]

Re: drive shaft hard to turn

It can be hard to turn because the dry friction of the waterpump impeller in the housing, if you want to check for that cause put the LU in water and see if it turns better.

problem persist even without impeller or upper housing.my replacment part was sierra 18-3314 (housings and seals and gaskets)could it b wrong part?drive shaft gets thicker towards the bearring.any thoughts?

 

[Lyle29464]

Re: drive shaft hard to turn

put new impeller on top of old one. bend one fin to conform with the old set. S/B same length except for small wear on the end. Make sure the gears are not locked up from being upside down etc.

 

[Faztbullet]

Re: drive shaft hard to turn

You got the wrong base as Sierra does not make one to fit a 1975 engine , the original base is 46-58618a1. The problem is the seals are binding on swell of driveshaft where they run,look at your old base and you will see the difference.

 

[kazek]

Re: drive shaft hard to turn

i am getting same thoughts.thanks faztbulet.got that part from the catalog and it said its for my model.does anyone still makes proper part for my motor?i did greased all parts and was able to free the shaft a bit ,but still feels not right.i guess i will have to dissasemble the whole water pump.back to square one

 

[oldman570]

Re: drive shaft hard to turn

Go to WWW. oldmercs.com or East coast Marrine as they list kits for the waterpump for your motor. Could try Seaway Marrine also.
Oldman570

 

[Faztbullet]

Re: drive shaft hard to turn

Sierra and Mallory do not offer a base for that year model, just return it and get the kit with just the upper housing and order new seals for your old base.

 

[kazek]

Re: drive shaft hard to turn

now i see.had to break upper seal to remove the wrong housing.gee i am glad i did not run my motor like that.thanx guys.got seals off old housing and came up with sierra #18-2050 for upper seal and 18-2007 for the lower.just have to wait till parts arive.thanx again faztbulet