3.0 mercruiser alignment?

Hello All,

This is my first post and i wish i had found this site prior to me taking on the task of replacing the belt on my engine. i just bought this 21' cuddy and had it on the water two times, the first time no problems seemed to be running great. The second outing a issue occurred, while cruising the engine began to make a squealing type of sound, looked at the engine and discovered that the belt was very loose as the alternator mounts where also loose and had shifted. With no tools on the boat i headed to shore and damaged the belt as it was rubbing on everything. Changing the belt looked easy, got a new belt from local marina ( dont ask how much, to painful to mention after looking on this site) and began to remove the bolts on the spacer that attaches to the block. As i was doing this the engine dropped about 1/2" the front pully was now resting on the front engine mount. I placed a jack under the engine to raise it up and slipped on the new belt, pulled the alt over and tightened the bolts, replaced the spacer mount and removed the jack. Engine starts and sounds good at idle, however when reved up it sounds to me that the shaft at the rear is making more sound then before (like a deep grinding sound) its had to say fore sure as i have only heard this engine about three times. My question is when the engine dropped could something become unaligned? If so how do you adjust alignment on this engine ? its a 3.0 merc alpha one 2008. Any info is appreciated. Thanks

Re: 3.0 mercruiser alignment?

The reason the belt keeps going bad is probably the pulleys are all rusty. That rust acts like course sand paper and destroys the belts in short order. The pulleys need, cleaned of rust. sanded smooth, and repainted with something like Rustoleum and allowed to dry a couple days before putting on a new belt.
And yes, you need to realign the engine after it dropped. You have to pull the drive, in order to check the alignment.
Here are a couple things you MUST read.

View attachment A1G2 R&R.pdf

And this http://forums.iboats.com/mercruiser...utdrives/engine-alignment-how-tos-443992.html

Re: 3.0 mercruiser alignment?

Welcome aboard, now that you are a boat owner you need to learn about your I/O and engine. If you would post your serial numbers here I bet one of these nice folks will direct you to a mercruiser service manual for your particular engine/drive unit. Then you will need to read it carefully and it will explain most everything you need to know to maintain your drive properly. I downloaded mine to a thumb drive
so I can pull up any information I need and then print just what I need. Unless you have very deep pockets you will soon learn the joys of drive maintaince and how expensive it becomes if you don't. Welcome............

Re: 3.0 mercruiser alignment?

Thanks for the help guys, i'm not sure if i want to tackle the alignment job. Are any special tools required or can a basic set of tools deal with this task? Also how long do you think a job like this would take? Im quite handy being a construction electrician for 20 years however never worked on boats before. Any idea how much a marina would charge to do the re alignment? Tomorrow i will get some serial numbers off the engine and drive and post them. Thanks for the help.