MEP-803A flywheel issue

[BrnH2ORat]

I just picked up a 803A from someone who bought it from auction, Has a new Tier 2 upgrade from 2012 with what looks like a new engine with just a few hours on the Hour Meter. Problem is the the flywheel is not attached to the crank! engine will turn over by hand (Fan blade) and can turn the flywheel/alternator freely from the ring gear with starter removed.
Trying to determine whether the flywheel is a single bolt with a taper fit and keyway or 4-5 bolt flange fit to the crank. Both ends turn freely, kinda hard to believe that it sheered off 4-5 10-12mm flange bolts. Going to pull the alternator off to inspect just wondering if this is a common problem? Saw another post on here with a similar problem but there was no outcome on that thread from 2019. I knew about this issue before I bought it, but for $300 dollars it was a cheap gamble, the overall generator is in great shape, everything there, worst case scenario would be a broken crank shaft.

 

[Ray70]

Oops, I see you created a new thread for your machine. Like I mentioned in the other thread,
It's not a single bolt. It's pretty much just like any other car engine. 5 bolts through the flywheel into the flange on the end of the crank.
You must have one of the 3 issues listed above. Bolts sheared off, bolts fell off or crank is broken.
BTW others have reported similar issues in the past.

 

[Ray70]

For $300 you can't go wrong! even if the crank is broken you're still like thousands ahead of the game!

 

[Light in the Dark]

Drive plate could have sheared too, I've seen that.

 

[BrnH2ORat]

Drive plate could have sheared too, I've seen that.

But isn't the drive plate bolted to the flywheel? The engine turns over but the flywheel doesn't move, turn the flywheel through the starter hole and the drive plate/fan turns.

 

[BrnH2ORat]

Not a single bolt. It's pretty much just like any other car engine. 5 bolts through the flywheel into the flange on the end of the crank.
You must have one of the 3 issues listed above. Bolts sheared off, bolts fell off or crank is broken.
BTW others have reported similar issues in the past.

The guy I got it from said he tried starting it, said it started to fire off but then the flywheel just spun, most 4-5 bolt flywheels also use a alignment dowel pin, I'm hoping someone at the depot who assembled the new engine in this forgot the bolts and the dowel pin finely sheared off. Going to pull it down next week and see what the mystery is!

 

[Ray70]

Well, that would be nice, but the TM shows 5 bolts and nothing else.
I've replaced a couple cranks before and don't recall there being a dowel pin, but I could be wrong, only one way to tell for sure.
If the crank ends up being damaged, I have a couple spares in my parts piles.

 

[BrnH2ORat]

Well I guess I'll know in a few days! I'm in the middle of doing the machine work on a Perkins 1104C, making 1 good engine from 3 bad ones. I'll have to figure out if this DN4M has stock crank journals, don't want to replace rods if I don't have to.

 

[Ray70]

Why would you need to replace rods? rods would never change, the bearing thickness changes when the crank is turned undersized.

 

[Light in the Dark]

But isn't the drive plate bolted to the flywheel? The engine turns over but the flywheel doesn't move, turn the flywheel through the starter hole and the drive plate/fan turns.

Yes it is, guess I glossed what you wrote. If the flywheel is stationary but the engine turns, I'd agree that you may have a crank issue here.