Volvo Penta 4.3gl Flywheel fell off.

king3585

Cadet
Joined
Jul 16, 2013
Messages
15
So I bought this 1997 Reinell 180 with a "new" engine. Sounded good and looked good but have been dealing with a fuel tank issue and running issue in another post. The other day while taking it out for a test I heard rattling noise from the flywheel housing. I shut it down and got towed back to dock. At first I thought it was a u-joint but then I found a handful of studs and nuts in the bilge. Upon digging into it (removing stern drive and pulling the engine) I found the flywheel had come free from the engine. Luckily, only one stud broke off in the crank which I was able to unscrew by hand. I can't see any damage other than the one broken stud. The others studs and nuts seem fine, however, the "locknuts" used spin freely on the studs (one of my questions - since they're "locknuts" shouldn't they require a wrench to remove)? Also, wondering why this happened. I can't see any evidence of locktight being used and I'm starting to think that they just forget to tighten these bolts down or didn't torque them properly. Second, question - I can't find the proper torque or tightening sequence online. Does someone have it or is there even a sequence? Any thoughts on this?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,309
Re: Volvo Penta 4.3gl Flywheel fell off.

So I bought this 1997 Reinell 180 with a "new" engine. Sounded good and looked good but have been dealing with a fuel tank issue and running issue in another post. The other day while taking it out for a test I heard rattling noise from the flywheel housing. I shut it down and got towed back to dock. At first I thought it was a u-joint but then I found a handful of studs and nuts in the bilge. Upon digging into it (removing stern drive and pulling the engine) I found the flywheel had come free from the engine. Luckily, only one stud broke off in the crank which I was able to unscrew by hand. I can't see any damage other than the one broken stud. The others studs and nuts seem fine, however, the "locknuts" used spin freely on the studs (one of my questions - since they're "locknuts" shouldn't they require a wrench to remove)? Also, wondering why this happened. I can't see any evidence of locktight being used and I'm starting to think that they just forget to tighten these bolts down or didn't torque them properly. Second, question - I can't find the proper torque or tightening sequence online. Does someone have it or is there even a sequence? Any thoughts on this?

Ayuh,... Welcome Aboard,... Sounds like the mechanic needed to get the right nuts, 'n Forgot,..

I don't lock-tite 'em, 'n donno the torque value,...

I run 'em in, in a cross pattern to good, 'n snug, then twist 'em, oh, 'bout 45/ 55 ft.lbs with my calibrated elbow,...
Also in a cross pattern,...

I'd Replace All the nuts, 'n All the studs myself,...
Hard to believe they're all untouched,...
 
Last edited:

king3585

Cadet
Joined
Jul 16, 2013
Messages
15
Re: Volvo Penta 4.3gl Flywheel fell off.

Do you use two nuts tightened together to install the studs or is there a better way? Thanks for your advice.
 

frantically relaxing

Senior Chief Petty Officer
Joined
Nov 19, 2011
Messages
699
Re: Volvo Penta 4.3gl Flywheel fell off.

My bet is a mechanic put the flywheel on, spun on the bolts by hand, then finished everything else by days later, and forgot to tighten the bolts. I remember the test fire of my Sportster after waiting 18 months- extended frame, new paint, bored & stroked, lotsa chrome, and 4 new cams--- which were stuck in the block by someone months before and nobody bothered to time them. Soon as the starter moved valves started hitting the pistons...ARRGGHHH
:mad:
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,309
Re: Volvo Penta 4.3gl Flywheel fell off.

Do you use two nuts tightened together to install the studs or is there a better way? Thanks for your advice.

Ayuh,... Get 1 Non-locker nut for that process,....
 

king3585

Cadet
Joined
Jul 16, 2013
Messages
15
Re: Volvo Penta 4.3gl Flywheel fell off.

Got it all back together and running but it seems to be running rough or really out of balance. I didn't notice any special alignment with the flywheel. Is there? Could just be related to plug wires or something else. Been having a bad time getting this thing sorted. Also, oil pressure is really low. Before the flywheel fell off it ran normal range of 20-40. Now it hardly moves the gauge. There's no shavings in the oil. Could the flywheel falling off somehow effect the oil pump? Thanks for any tips. On the verge of pulling the engine and doing a rebuild....
 
Top