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changing engine mounts

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bobct

Advanced Contributor
I'm changing all 8 of my engine mounts and got 3 of 4 done today on one side. If you recall my post from last week, my fairly new cutless bearing was worn (and the rubber was loose, maybe a manufacturing defect). I noticed when the boat was hauled that the shaft was a lot closer to one side of the shaft log. I'm going to get it dead center and do whatever I need to do to the cutless bearing to keep it that way. Then I should be able to do an easy alignment with all new mounts.

What I noticed in removing the mounts was the pinch bolts that clamp down on the trunnion weren't super tight. I was the last one to tighten them and intentionally did not over torque them. Since I have to remove the bracket and mount (not enough room to slide the mount off the trunnion and clear the stringer), I found out something interesting on the bench.

You have to torque the bolts really tight so the trunnion doesn't slip on the mount. Much tighter than I would normally tighten a bolt of this size. Do you guys find the same? Now I know why the shaft was so much closer, the engine must have "walked" to the left over the course of the season. I think what I 'll do is use some touch up paint to mark the final position(s) so I can check them during the season.

What do you guys think?

Bob
 
I found it amazing that the mounts would slip by themselves. I had to remove ALL of mine, clean them up, and lube them to get them to move!

Jeff
 
One of the rears I had to bring home because I couldn't get the mount separated from the bracket. It was one of the front mounts that still moved after tightening the nut (off the engine). Maybe you're right, just a coincidence.

The other front which I adjusted a couple of years ago, actually turned out to be slightly bent as was the bolt. That must have "felt" like an adjustment on the trunnion.
 
Bob:

check the trunnion to ensure the metal forming the "slot" hasn't been reshaped in a manner that would keep the pinch bolt from compressing the clamping ears...the other item is to make sure the pinch bolt/nut aren't stripped out...those are the only two issues I've ever seen that would allow the mount's clamp to "move" on the trunnion.

You may find it educational to dissect the old mounts - i did one of my old fronts a while back and was amazed at the poor physical condition of the internals of the mount...take a die grinder to the top or bottom of the "lag bolt sleeve" and it comes apart pretty easy...
 
Mark,

I remember you saying that a while ago, that's partially the reason I'm changing all of them...your bill is in the mail :)

Did you find that was true for the ones that "looked" good too? I have a couple that look as good as new and they rotate freely. I'm glad I'm doing it though because I really never had a chance of getting the side to side correct the way they were frozen on the trunnion. At a minimum, I would have had to remove all of them and then reinstall. I don't know if I would go to that much trouble on 25 year old mounts.

I think on a lot of boats, you can slide the mount over because it's on top of the stringer or there's enough on the side. That was not the case for me so it's been a lot more work.

Bob
 
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