Mercruiser 3.0L belt replacement - motor mount obstructing

[michael7373]

The alternator belt appears to be stretched beyond adjustment as I'm already maxed out on extending out the alternator and there's still probably a 1" play in the belt and it squeaks at RPMs just above idle. I'm looking at how to replace it and it looks like the motor mount is in the way. I've done a lot of searching over the past couple of days and have seen some remove the water pump pulley and some say they've removed the motor mount. I'm trying to find out what is best / easiest / safest. It looks like just the washers on top of the mount need to come off and that would give me enough room to slip the belt in and out.

Any help will be greatly appreciated.

Thanks,
Michael

 

[Alumarine]

On the port side of the mount there is a removable block that will allow you to replace the belt.
It's a good idea to insert a spare belt in there for later.
Some people, support the front of the motor when they remove the block, some don't.
I never have.

 

[michael7373]

Thanks for the response. I saw that that block needs to be removed (and like you said, saw where some said to support the motor so that bolts line up easy when you put them back). But I still need to get it over the pulley which means I have to wedge the belt between the motor mount and that pulley. I'll attach another picture to show.

Thanks,
Michael

 

[Alumarine]

That must be newer than ones I've worked on.
I have one belt for both the alternator and pump.
If there's no room then I guess you'll have to loosen or remove the pulley bolts.

 

[achris]

That must be newer than ones I've worked on.
I have one belt for both the alternator and pump.
If there's no room then I guess you'll have to loosen or remove the pulley bolts.

That front belt, heading off to the left, is driving a power steering pump.

And yes, that needs to be removed to be able to fit a new alternator belt. That or remove the entire front mount. I'd just remove the pulley.

Chris. ...

 

[fishrdan]

Remove the pulley as achris said.

Also, the pulleys are rusted, and this will tear up belts. Sand the pulley groves and paint them with Rustoleum.

 

[michael7373]

That must be newer than ones I've worked on.
I have one belt for both the alternator and pump.
If there's no room then I guess you'll have to loosen or remove the pulley bolts.

Wasn't meaning mine was diff in that sense. One belt drives the water pump and alternator. Then the power steering pump driven off the other belt.

The fiberglass seat housing blocks direct access to the pulley for an impact wrench. So I'll have to take that off.

I'll get those pulleys painted too while I have the belts off. Haven't seen any wear on the belts yet. Just the water pump / alt belt has stretched.

Thanks!

 

[Alumarine]

You don't need an impact wrench to get those off.
A quick pull with a closed end wrench (or spanner, if you have one of those) will often break them loose.
Or, use a piece of flat iron or long screwdriver between two bolt heads to hold the pulley while you loosen the bolts.

 

[michael7373]

Thanks for the tip. I got the bolts off using a 1/2 inch chisel to hold it. Will I need a puller to get it off?

 

[Alumarine]

Thanks for the tip. I got the bolts off using a 1/2 inch chisel to hold it. Will I need a puller to get it off?

There might be a bit of rust holding it on.
Slight taps with a hammer should do it.
Maybe a shot of WD40 or whatever you have on hand.

 

[GA_Boater]

Work a flat bladed screwdriver between the outer pulley and the balancer. It will almost fall off if the centering guide isn't rusted and the belt is loose.

 

[fishrdan]

Haven't seen any wear on the belts yet. Just the water pump / alt belt has stretched.

Looks like the belts are worn, not stretched. All that black dust on the manifold's end sticker, looks like shredded rubber from the alt belt. Bit of sanding and paint will solve that though.

If using Rustoleum paint, I would let it cure for at least a week (or more) so the paint is cured hard, and the belts don't tear it up. Rustoluem cures pretty slow. Other rattle can paint will cure faster, but won't last as long.

 

[achris]

Work a flat bladed screwdriver between the outer pulley and the balancer. It will almost fall off if the centering guide isn't rusted and the belt is loose.

That pulley is not on the balancer, it's an addition to the water pump pulley, for the steering pump.

Chris.......

 

[GA_Boater]

That pulley is not on the balancer, it's an addition to the water pump pulley, for the steering pump.

Chris.......

Ooooops. Used the wrong pulley name. Thanks for the correction, Chris.

It still almost falls off because the PS pulley is an add-on to the water pump pulley.

 

[achris]

... It still almost falls off because the PS pulley is an add-on to the water pump pulley.

:thumb:

 

[michael7373]

Looks like the belts are worn, not stretched. All that black dust on the manifold's end sticker, looks like shredded rubber from the alt belt. Bit of sanding and paint will solve that though.

If using Rustoleum paint, I would let it cure for at least a week (or more) so the paint is cured hard, and the belts don't tear it up. Rustoluem cures pretty slow. Other rattle can paint will cure faster, but won't last as long.

I got the belts out from around the water pump pulley. Thanks!

How would i get to the crankshaft pulley for sanding / painting? Am I supposed to be able to turn that to get to it completely? I've seen where people suggest using the alternator to turn the crankshaft and that may work for sanding, but not for painting.

Any suggestions on how to sand? Just a sanding sponge? Wipe clean with a damp cloth?

Thanks

 

[fishrdan]

Sanding, I'd use 100 or 80 grit paper. Sponge is a good idea, anything that will apply even pressure and get into the groove. I've done it by hand too...

Crank pulley will be a pain to paint with then engine stopped.... Pull the coil wire and have someone turn over the engine over while painting the pulley groove. Couple of light coats as you don't want the paint dripping down the pulley. I wouldn't "start" the engine as the pulley will sling paint off it...

 

[michael7373]

Thanks everyone for the help. I got the pulleys sanded and belts replaced. I'll paint them in the off-season. Needed to use the boat this weekend so didn't have time. Thought I would add some notes here for future help.

I found a bottle jack on a 2x4 under the alternator mount helped get the bolts off and and on for the removable block on the port side of the mount. I removed the bolts without support and then had a hard time getting them started when ready to put them back in. After putting the jack under it and lifting slightly (no more than finger turning the jack a couple of times), they slid right in.

For getting the belts around the water pump pulley (where there was no clearance from the mount), I loosened the 4 bolts (using a 1/2" wood chisel to keep from rotating it) and slid the pulley off the shaft. The pulley wouldn't make it past the motor mount b/c there wasn't enough clearance. But I was able to tilt the pulley forward enough to allow the belts to be slipped off and on with ease.

Thanks again for all the help!

 

[Alumarine]

Glad you got it going, thanks for the update.

 

[achris]

Did you put a second belt in place and tie it back as a spare?

Great tip with the bottle jack. :thumb:

Chris.