How tight should rear motor mount bolts be during and after alignment?

[wisebob]

A little confused about the alignment process in relation to how tight the rear motor mount bolts should be. I know the service manual says 45 lb ft but do you torque them down right at that from the start before adjusting the front motor mounts during alignment? If not, how tight should they be initially?

Seems like they should be loose before adjusting the front mounts as far as stress on the transom plate but once you tighten them, you'd throw the alignment off. Confused...

Also, what's the purpose of the spring washer that sits inside the fiber washer???

Thanks.

 

[muc]

Rear mounts get tightened last. If the alignment changes when you tighten them it means something is wrong. The 2 most common problems are, you have unequal weight on the front mounts or the inner sleeve of the rear mount twisted when it was tightened.
The spring is there to try and stop the twisting, it didn't always work so Mercury changed the design of the mount to do away with the spring.

 

[alldodge]

Rear mounts get tightened last.

Will take your word for it but my 2002 install manual indicates to tighten them to 38 ft lb and later do alignment. This being the case, when alignment is rechecked during regular maintenance, and adjustment is needed, are the rears mounts to be loosened prior to adjustment?

 

[Bt Doctur]

Being that engine alignment is so critical you tighten the rear mounts down first, then adjust the front mounts untill alignment is achivied..
If you cant get it aligned then something else is still wrong.
the rear mount is an aluminum sleeve encased in rubber with a thin outer sleeve.

 

[Bt Doctur]

http://www.bing.com/images/search?q...&thid=OIP.M2f9d06e629defc724425e8cfb6bced83o0

 

[wisebob]

What can be done if the gimbal bearing looks like it is a little left of the engine coupler?

Thanks.

 

[Bt Doctur]

Sounds like there is more here than your telling . It wouldnt be the first motor I`ve seen wrong from the factory.. If you install the motor and tighten the rear bolts
the only adjustment you have is in the front mounts. If you installed the motor by leaving the front mounts lagged to the stringer, those mounts might be in the wrong place.
If you did not remove the front mounts with the motor, remove the lags, loosen the rear bolts and shift the motor left or right to get lined up.Once lined up , tighten the rear bolts and procede with the alignment . Once aligned, mark the new location for the lag screws and fill in the old holes.
You might want to get hold of an old inputshaft and undercut it 1/8 of an inch where it passes thru the gimbal bearing. You cut off the U joint part and machine it 1/8 inch undersize of the gimbal bearing.insert and viisually see where the motor has to be moved to have 1/8 inch clearance inside the gimbal bearing. then do a final alignment wit the correct tool.

 

[Rick Stephens]

Sounds like the gimbal bearing is just aimed to the side. You should be able to stick your alignment bar in and shift it to point at the coupler. Gimbal bearing is designed to do just that.

Might also be possible the rear mount bushings are shot. I can't imagine, unless there is a flaw somewhere, that you can see a shift left or right in the alignment if the bushings are in good shape..

Rick

 

[Fishermark]

Sounds like the gimbal bearing is just aimed to the side. You should be able to stick your alignment bar in and shift it to point at the coupler. Gimbal bearing is designed to do just that.

Just to add to what Rick mentions, the gimbal bearing needs to be "set." you do it be putting the alignment bar in and as far into the coupler as it will go, then tap / pound on the bar in four directions - left, right, up, and down. This sets the bearing. You may need to do it a couple of times as you adjust the alignment of the engine. Tap / pound means more than a tap, but less than putting your weight into a five pound sledge.