Merc motor mounts
 

I had my engine installed a few months ago. After the install I checked to see if the tabs were locked down. It appeared that they were. Last week I noticed that the port side mount dropped down about 1.5 inch. The top nut did not move so I lifted the engine and tightened the bottom nut back up. I didn't see any rubber shavings in the coupler area. I ran for about 10 hours, no problem. Yesterday I noticed the star. mount moved down about 1/4 inch. I pulled the drive and the alignment tool goes right in.

Is there a way to tell if any damage occured to the coupler? Maybe grab the snout and see if there is any play? Is there a way to make sure they don't move again?

Re: Merc motor mounts
 

Tab washer mounts above bottom nut. It is meant to grab a flat from bottom nut and another tab is bent around the block mount, so bottom nut can't move.

If nuts move easily, get new ones; nylon section can become too worn to retain itself. Also, original mounts have a small strip of reusable locktite on stud. This may have disappeared or not been adequate to begin with.

Make sure tab washers are UNDER motor portion of mounts, above lower nuts.
I would bend tabs free at lower nuts.
Run lower nuts down to allow BLUE locktite to be added to studs.
Run nuts back to correct postion using alignment tool.
Bend tab onto nearby nut flat, and another tab around motor bracket of mount.

Like this.
http://www.mercruiserparts.com/Show_...NGINE+MOUNTING

Re: Merc motor mounts
 

One of the other guys on the Donzi problem thread a few weeks ago mentioned putting hose clamps around the mounting bolts as spacers/relievers.

Re: Merc motor mounts
 

Metal shavings are a pretty good indication of coupler damage. Did you see any when you pulled the drive off?

Re: Merc motor mounts
 

I didn't see metal or rubber shavings. I didn't see any blue locktite on my mounts either. Is that something that the shop doing the install applies? The mounts are brand new with the engine. I'm hoping that I caught it in time or just got lucky and the coupler didn't get hosed up.

Re: Merc motor mounts
 

Don't sweat the coupler. Just make sure you grease it often with the blue synthetic slpine grease; Merc or Sierra. Says for u-joints, too. Marine grease for gimbel bearing and hinge joints/upper pivot shaft.

Blue loctite is what YOU should apply. It will just make the nuts more resistant to loosening.

So, is the tab washer in the correct place? And is one tab bent to the motor mount?

Re: Merc motor mounts
 

Look inside the coupler from the transom with the drive removed. The face of the teeth on the inside where it contacts the spline should each have a small flat surface. When a coupler is worn, the flat spots on the teeth will become sharp points facing the center of the hole. This is caused by misalignment and lack of lubrication.