Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

[tmongiello]

Good afternoon, I need some help as I am stuck. I have a 1994 Aquatron with a 3.0L Mercruiser. Today the Alternator belt decided to break. I have a spare but I cannot figure out how to get the damn thing on.

How things look on my boat: looking aft at the front of the motor you have the power steering pump on the left, the idler pulley in the middle, the alternator to the right and, of course, the main pulley connected to the motor shaft in the middle below the idler pulley. Please see diagram, sorry, couldn't take pictures due to the way the motor is in the boat, no way to get an angle....

I did read a thread about removing the motor mount spacer block, looks straight forward enough but the belt still will not come off as the idler pulley has 3 grooves and is so close to the front motor mount that it is impossible to push or pull a belt between them.

Most of the other threads on replacing the alternator belt said to just push it between the two but please trust me when I say, it isn't going to happen on my boat. There are 4 bolts on the front of the idler pulley and I removed all 4 of them easily enough but the pulley will simply not budge. I can't seem to remove it to get the old belts off and the new belts on.

Can someone give me some insight as to how the idler pulley comes off?

Please and thank you. All help and replies are greatly appreciated.

Tony

 

[oldjeep]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

That's not an idler pulley, it is the water pump.

Isn't this the belt routing anyways?

 

[tmongiello]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

Yes! that is the correct layout and yes, I misidentified the water pump thank you for correcting me. Maybe why I couldn't find any info was because I was searching for the wrong thing. So, problem still remains. The alternator belt is around the crankshaft pulley, the Water Pump, and the alternator pulley. The is the belt closest to the motor.

The pulley on the water pump has three grooves. Only the ones on the edges are user (back for alternator, front for power steering). the center one isn't used.

Between B and C is a motor mount that is so close to the water pump pulley that I cannot get a belt between the pulley and the mount.

Is there a way to remove the outermost pulley on the water pump so I can replace the belts?

Thanks for the fast reply!

T

 

[achris]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

You will need to support the front of the engine and completely remove the front mount if there is no clearance.

Chris.....

 

[tmongiello]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

Thanks for the reply! Just to replace belts??? Who at Mercruiser thought THAT was a good idea? LOL.

 

[achris]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

Thanks for the reply! Just to replace belts??? Who at Mercruiser thought THAT was a good idea? LOL.

When Merc original supplied your engine, there would have been a spare belt tried down and in place ready to go. Someone may have removed it or used it and not replaced it....

 

[tmongiello]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

When Merc original supplied your engine, there would have been a spare belt tried down and in place ready to go. Someone may have removed it or used it and not replaced it....

Well, since this boat is a 1994, then I am guessing that the spare is LONG gone. LOL. Seriously, I cannot believe there isn't an easier way to change this damn belt without having to lift to damn motor halfway out of the boat.

Due to the way my boat is constructed, I cannot see the front of my motor from the front, only the top. Now looking for diagrams/pictures of the front so I can see how to lift the motor to get the clearance I need to install the belt. If you have any pointers/instructions, I'd be most grateful.

Thanks!

T

 

[tmongiello]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

This is pretty much what I am working with except I only have 6-8" of space between the motor and the back of the bench seat (which is part of the top cap of the boat). How do I give myself the clearance I need to install the belt? What do I loosen and jack up?

Thanks!

T

 

[achris]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

Ok... Here's how I would do it... And Don't blame Merc for the crappy boat design. The designer of the BOAT needs to be kicked for not considering engine maintenance...

Remove power steering belt, loosen alternator mounting and slip the belt off the alternator and water pump pulleys. Remove the 4 bolts holding the water pump pulleys to the water pump flange and remove the water pump pulleys. Remove the front mount spacer under the alternator. Remove the old belt, fit new belt (and a spare!) and reverse the above procedure....

Chris.....

 

[tmongiello]

Re: Please help! How to remove idler pully / replace alternator belts on a 3.0L Merc

Ok... Here's how I would do it... And Don't blame Merc for the crappy boat design. The designer of the BOAT needs to be kicked for not considering engine maintenance...

Remove power steering belt, loosen alternator mounting and slip the belt off the alternator and water pump pulleys. Remove the 4 bolts holding the water pump pulleys to the water pump flange and remove the water pump pulleys. Remove the front mount spacer under the alternator. Remove the old belt, fit new belt (and a spare!) and reverse the above procedure....

Chris.....

Thank you so much! I tried earlier to remove the water pump pulley and failed. Is there a special way to do that? I removed the 4 bolts but the thing in the center is round, nothing to grab on to with a wrench. Was that supposed to be a bolt head at one time or is there a special way to remove the pulley?

Thanks!

T