Mercury bearing carrier and shift problems.

[dpoetting]

I just replaced my prop shaft seals and o-ring. I pulled the bearing carrier and re-installed. I had the bearing carrier nut tightened at my local boat shop. Now the engine will not go into gear...at all. What did I do wrong? It seemed like it was a pretty straight forward job. The engine in a 1985 Mercury outboard 75 HP.

 

[Big flop]

Re: Mercury bearing carrier and shift problems.

Is the problem with the lower unit on the motor?
Miss-aligned shift shaft?

 

[dpoetting]

Re: Mercury bearing carrier and shift problems.

The motor ran and shifted fine before the work. I did not pull the lower unit. I just drained the oil and pulled the bearing carrier, replaced seals and put back together.

 

[Big flop]

Re: Mercury bearing carrier and shift problems.

Was the prop shaft removed or slid back?
The shift pin in the front of the prop shaft
rides against shift cam may have fallen out?

 

[Wingedwheel]

Re: Mercury bearing carrier and shift problems.

Did you notice if the cam follower might have fallen out?

 

[dpoetting]

Re: Mercury bearing carrier and shift problems.

I think it may be the cam shift. I was hoping to not have to take it all apart again. Is there a trick to getting everything to line up again? Could I have possible damaged anything? I'll tear it down tomorrow and let you all know what I find.

 

[Wingedwheel]

Re: Mercury bearing carrier and shift problems.

Did you remove the LU when you removed the carrier? If so then the problem may well be the shift-cam in the wrong position. Thats easy enough to fix by dropping the LU again and turning the cam until its back in the correct position.

 

[dpoetting]

Re: Mercury bearing carrier and shift problems.

I did not remove the lower unit. Here's an update. I just pulled the prop and the bearing carrier nut was loose. Even after the shop tightened it for me. I tightened it down as much as I could, and the gears seem to be engaging. Why would that nut have come loose with the locking tab in place?

What direction should the propeller spin freely in forward and reverse?

 

[Moody Blue]

Re: Mercury bearing carrier and shift problems.

If the locking tab(s) was engaged in one (or more) slots in the carrier nut, the nut could not have come loose. Sounds like it was never properly tightened. The spec for my unit was something like 250 ft/Ib of torque to tighten.

FWD = prop turns freely one direction and ratchets in the other
REV = prop locked in both directions
Neutral = prop spins freely in both directions

 

[Big flop]

Re: Mercury bearing carrier and shift problems.

Are the threads in the lower unit
housing where the carrier nut threads
in ok?
It should not spin freely in forward
or reverse gear.

 

[dpoetting]

Re: Mercury bearing carrier and shift problems.

I watched the shop tighten the nut. They used an air gun on the bearing nut tool and got it tight. The locking tab was bent back. But when I pulled the prop off and released the locking tab the nut just spun freely loose. It's like something was not letting the bearing carrier seat fully and then it dropped into place, making the nut loose.

In forward gear the prop locks counter clockwise and free spins clockwise. In reverse gear the prop locks both directions. Sounds like I may have found the problem. I will get it all back together tomorrow and give it another try.

 

[dpoetting]

Re: Mercury bearing carrier and shift problems.

Well, I tightened the bearing carrier nut as much as I could and refilled with oil. Fired it up and it now works fine. The propellor looks like its sitting further in now too. Looks more like it should. Now to see if I cured my leak. Thanks for everyones input.

 

[Wingedwheel]

Re: Mercury bearing carrier and shift problems.

if you don't get that retainer nut tightened to the proper torque, you'll still get water in the LU

 

[chesapeakemilkman]

Re: Mercury bearing carrier and shift problems.

Did you notice if the cam follower might have fallen out?

I have a similar problem. If the cam follower did fall out, would it be in front of the forward gear? If so, is there an easy way to get it with out removing the drive shaft?

 

[Yesterday]

Re: Mercury bearing carrier and shift problems.

As Moody Blue mentioned the spec for the spanner nut is 210 - ft lbs, and I'm sure I had read in service documentation that spec is necessary for proper shifting operation. I wonder how that torque was achieved with an air impact wrench?!

 

[chesapeakemilkman]

Re: Mercury bearing carrier and shift problems.

I have a similar problem. If the cam follower did fall out, would it be in front of the forward gear? If so, is there an easy way to get it with out removing the drive shaft?

Thanks Wingedwheel. I found the cam follower on the ground this morning and all is back together again.