how to check u-joints

[slredstorm62]

my 87 mercruiser has a knock but i think its in the outdrive. possible u-joint? can i check u joints while in the water or do i have to pull the outdrive off? and would loose u-joints make a constant knocking noise or is the driveshaft only move when boat is put in gear

 

[Haut Medoc]

Re: how to check u-joints

my 87 mercruiser has a knock but i think its in the outdrive. possible u-joint? can i check u joints while in the water or do i have to pull the outdrive off? and would loose u-joints make a constant knocking noise or is the driveshaft only move when boat is put in gear

They can make noise either way....
The only way to truly check them is to pull the drive & disassemble them....
Even then, defective/worn ones are not always obvious.....
They are like $25 apiece right here at iboats....
I would just replace them.....

 

[slredstorm62]

Re: how to check u-joints

can someone tell me what parts i need to order. i will probably replace u joints gimbal bearing and the seal on the outside of gimbal bearing where the gear oil is leaking into my bilge. it is a 1987 mercruiser alpha one 3.0l with an alpha one with powertrim transom number s/n is 0B511930 engine number s/n is B483822 and the drive unit s/n is 0B467167

 

[Bt Doctur]

Re: how to check u-joints

The oil is leaking from your outdrive , the seal behind the bearing does nothing.
#19 here http://mercstuff.com/ficheb.htm GEN II
Or Alpha here #20 http://mercstuff.com/fichea.htm

 

[Evinrude Boater]

Re: how to check u-joints

I'm not sure you've really determined if the noise is going to be eliminated by replacing u-joints etc. The driveshaft is always spinning when the engine is running. Does the sound change when you shift gears or when you raise and lower the outdrive when running? When was the last time you inspected the u-joints and greased them? Are the bellows leaking?

 

[slredstorm62]

Re: how to check u-joints

the noise stays the came when shifted into or out of gear and it will go consitant with engine speed but will not get louder. i cant hear it over the engine while running. only at idle. how to i see if my bellows are leaking?

 

[hoot]

Re: how to check u-joints

start by raising the outdrive and looking at the bottom of the drive bellows. turn the drive to the left and look at the right side of the bellows and vice versa. you need to stretch it out and look for small cracks. and pull the drive. if water is in there, a gooey mess will run out on your shoes!!

 

[bruceb58]

Re: how to check u-joints

Looking at the bellows externally is a waste of time. Pull the drive. You should be pulling the drive annually anyway.

 

[tacconelli6]

Re: how to check u-joints

Bruce is on. Pull the drive, if water is in the bellows then you know they are shot. It is just six bolts. If you pull the drive you may need to get a gasket set to replace the outdrive gaskets and O-rings.

 

[Alpheus]

Re: how to check u-joints

If you pull the drive you may need to get a gasket set to replace the outdrive gaskets and O-rings.

You ALWAYS replace the gasket and O-rings every time the drive is pulled...