Broken engine coupler flex plate

[Wolford.118]

My engine coupler (triangular style) flex plate broke near each washer. I can't seem to find any posts from anyone else having this issue so i am concerned as to what the cause of the failure may be. Has anyone else had this problem? If so did you find the root of the problem?

The Fly Wheel has only.003 runout on it so I think that is allowable, and none of the bolts were loose. The only thing that makes sense to me is the rubber pieces between the flywheel and the coupler dry rotted and came out allowing the coupler to have some movement as the rubber bushings were broken in several pieces and laying in the bottom of the flywheel cover.

It is a 1994 Starcraft with a 4.3L engine Alpha One Gen 2 drive with only 360 engine hours, If that is helpful.

Also is there a special procedure for installing the coupler? my shop manual doesn't seem to have a step by step guide, but I have read that using tapered screws is recommended then installing the regular bolts one at a time.

 

[alldodge]

It's not normal to have them break like that. The washers should be metal not rubber. There are three rubber bumpers which go in between each piece so keep vibration down. The only way I'm thinking it broke like it did was the alignment was out, or a motor mount is soft

 

[Wolford.118]

Thanks for the reply. The bumpers were the rubber I spoke of. The motor mounts are solid. I think the coupler was cracked or partially broken when I bought it this winter as it had a slight vibration. So it is possible that the previous owner had missaligned it but the gimbal and U joints were all in good condition so I didn't think that was the issue, but perhaps it was.

 

[alldodge]

You probably already have but look at the flywheel real close to see if it has a crack.


Other then that, maybe just a manufactures defect or as you say there was something wrong with the coupler by the PO

 

[JonBrown]

I have had a customer do this same thing. He hole shots pretty hard after a beers and shifts rapidly. And it is also a 4.3 2010 sea ray model TKS engine. I have never seen this before although with replacement and alignment it has been fine 2 years. So if it is his fault or the part I am not sure. But a new one seemed to fix the problem. Those plates on the 4.3 are kind of flimsy though. My 2.5 cents worth, hope it helps...
jon

 

[Bondo]

I have never seen this before although with replacement and alignment it has been fine 2 years.

Ayuh,.... I haven't seen that failure either, but even uncommon failures happen all the time,....

If everything checks out, throw a new coupler on, 'n go Boatin',....