SmallPP

Hi team. Quick question: Is there any need to ever change the height of the rear MerCruiser engine mount? Specifically, has anybody ever had to put shims in between the motor bellhousing ears and transom plate receiving holes? I have worked on 3 boats in a row now where no matter how the front mounts were adjusted, the drive would not go on (Alpha 1 Gen 1, and older). The drive would only go on smoothly if the motor was lifted very slightly with a hoist. I'm scared this is putting stress on the gimbal bearing and drive shaft. The boats are mid 80's and older using Chevy 350's (Merc 260's). Seems like metal to metal with a fiber washer in between, so I don't uinderstand what is changing.

At this point I am open to guesses, suggestions, and past experience please! Thanks for the words. I'm happy to chime in when I can.

Clint

OffshoreOnly

Engine alignment is extremely important. You need to re-drill the brackets or replace them if the holes are too close to where they need to be. Not guessing, past experience.

What is changing? Perhaps nothing. Many boats never are aligned right from day one. Are the motor mount race mounts or standard mounts? Are the stringers detiorated causing the brackets to move? If you have to lift the motor you got a problem that needs to be fixed.

SmallPP

Thanks, but I don't understand your response. A typical MerCruiser setup has the rear motor mount as two vertical holes (horizontal ears with holes in them) which sit atop each other (bellhousing and inner transom plate). There is no adjustment that I can see. To raise the engine rear, spacers or washers would have to be inserted in between the bellhousing ears and the inner transom plate ears. See:

http://216.37.204.206/Shorts/mercrui...=113&A=39&B=24

for a reference. Drilling would not do anything, or maybe I'm missing something? The fronts seem fine. This problem is at the rear only as I have tried every front height adjustment possible. I don't mean to sound snotty, my writing just sounds that way. I totally appreciate anybodys help on this.

OffshoreOnly

do you have front and rear motor mounts? Prevous post refers to the motor mounts not the picture you provided.

dlbCheckmate

Look at the inner transom mount plate, you may be able to loosen it and "realign" it there is a slight amount of clearance in the through holes, this could be where some of the missalignment has come from. But I agree that the boat may not have been set up correcly from the start. My o2

Dave

SmallPP

I think they are (or were) doing crummy jobs of alignment at MerCruiser from the factory. My Chevy 5.7L mounts same as most other production, bellhousing mount in the rear with two ears, and the a mount on each side of the engine near the front. The two side mounts are adjustable in height, which has not fixed the problem at any setting. Thanks again, and keep the ideas pouring in. I'll try all of them!

Clint

David

On the page you linked to, item 14 is a spacer that goes on top of the gimbal housing pad, and the flywheel housing sits on top of that. # 14 is a special double wound lock washer. There normally is a fiber washer that fits around the OD of #14. Spacer #12 sits on top of the flywheel housing

David

Oh, BTW- do you have a big boat? to make up for your screen-name? J/K, you know.

Greg Mc

I too have an Alpha 1Gen1. I just had the rear motor mounts in the rear replaced. Merc. Has a new way of doing it now. They still use the fiber washers but instead of the double wound lock washer they use a flat washer. I had to have the rubber mounts pressed out of those ears and different ones put in. The Mech. said the old ones let the engine move around too much.

Mrs Cord

Mercruiser doesn't align the engines. That is the responsibility of the builder. If the drive won't slide on, then the alignment is totally fubar. Get the alignment tool and check it. The transom assembly holes are drilled oversized for this purpose. Loosen it and you can slide it around a little bit. A rubber mallet works good for this.