Flywheel bolts came apart

[djnordeen]

Hello,
I have a 1997 pontoon. with a volvo penta 3.0l. Looks like a MichiganMotorz engine.
Don't know when it was installed.
Flywheel studs (nuts), fell off and sitting below.
At this point I am disassembling the engine and rebuilding.
Studs are broken in the crank. Not sure it if hurt the crank.
Any advice would help me move forward
Thanks, Dan

 

[Bondo]

Ayuh,..... Pull the drive, then the motor,.....

Once on the floor, you can access the damage, 'n plan a fix,.....

Gettin' the broken studs out oughta be fairly easy,....
I'd center punch 'em, 'n try to back 'em out with a lefthanded drill bit,.....

 

[alldodge]

Most likely its just the bolts, the PO didn't use loctite

 

[Scott Danforth]

PO either didn't use loctite or didn't torque to spec

 

[djnordeen]

Thanks for the replies.
I got drive and engine out ok.
The holes for the flywheel coupler are elongated a little bit. Is that going to be a problem?

 

[Scott Danforth]

The holes for the flywheel coupler are elongated a little bit. Is that going to be a problem?

yes

 

[alldodge]

Check the part number on the flywheel, might have put the wrong one on the motor

 

[djnordeen]

Here is a pic of the coupler

 

[alldodge]

What's the serial number of the motor. In 1997 Merc used the triangle coupler. Could be the PO replaced it with the wrong one and used the wrong bolts

 

[djnordeen]

What's the serial number of the motor. In 1997 Merc used the triangle coupler. Could be the PO replaced it with the wrong one and used the wrong bolts

No serial number on motor. It's painted black. Maybe MichiganMotorz.

 

[alldodge]

Starting in 1989 Merc went from a coupler bolted to crankshaft with studs to the triangle which bolts to the outer flywheel. In link you will find both and parts listed. If yours was held in with bolts and not studs, then this would also cause an issue

https://www.mercruiserparts.com/bam/subassembly/30912/963/300

 

[djnordeen]

I found the serial number for the block.
3857760. type LB 30L.
So Long Block 3.0 replacement.
# 2 spark plug came out very wet.
So, I assume that the coupler is correct. Studs with nuts.
Thanks for the link

 

[muc]

Thanks for the replies.
I got drive and engine out ok.
The holes for the flywheel coupler are elongated a little bit. Is that going to be a problem?

Yes

 

[djnordeen]

Ok, Finally Spring is here in Michigan. Got a good used coupler and putting it back together. Tiding up things, wiring and engine compartment mess.
Thanks for all the help.

 

[djnordeen]

Ok, Question about the engine mounts.
Rear Flywheel Housing to boat assembly procedure.
Picture below,
1. square nut (15) to bolt (12) torque spec?
2. upper nut (13) torque spec?

Thanks, Dan

 

[alldodge]

My eyes are not good enough to read those numbers

 

[djnordeen]

Yeah mine too
The parts are is the lower left corner
I'll get a link to a better picture

 

[alldodge]

Looks like some kind of inboard mounting. Base torque on size of bolt

Stern drive uses 35 - 40 ft lb

 

[djnordeen]

Ok, Thanks.
Yes, I/O pontoon.
The issue is that when the engine is in you cannot easily get a wrench on the head of the bolt to put the upper lock nut on. It just spins it out.
The square nut, I believe is to hold the bolt so you can tighten the upper lock nut.
Which is why I was looking to see if there were two different torque specs.
Thanks for the reply

 

[djnordeen]

Ok, I got it bolted in.
Torqued the square nut to 65.
Upper nut to 50
Thanks for the help