Gimble bad?

[starsnstripers]

1984 Mercruiser Alpha 1 260hp Got engine fired up tonight, Ran great, I checked the gimble before installing the drive, it felt good, looked good turned smooth, no play and freshly greased. While running engine i hear an intermitting cracking/rattle sound from the shaft area. Also picking up a vibration at about 1200 rpms. Did proper alignment with tool. Anything to check, or pull drive and do bearing?

 

[tractoman]

Re: Gimble bad?

U joints come to mind in theat region.

 

[starsnstripers]

Re: Gimble bad?

Yeah, they're real close to the gimble bearing. Sounds coming from inside boat near drive coupling/gimble bearing area.

 

[starsnstripers]

Re: Gimble bad?

Is it typical for a gimble bearing to make a crackle sound if bad? As for the vibration i used the larger flywheel i think it's the 14"from a 454 with the triangle style bolt to flywheel coupler. Balance issue maybe? What to check?

 

[bruceb58]

Re: Gimble bad?

Did your 454 flywheel have balance weights on it? I always thought that 454s were externally balanced. Maybe someone will comment that knows more.

 

[starsnstripers]

Re: Gimble bad?

I didn't think so. In the parts breakdown for my engine it can take a 14" fly wheel part#230-9425. When i looked up the 330 (454) and the next newer 454 the #s are 2305634 for the 330 (1982-87) and 2306540 for the alpha (1986-88) All have two piece rear seal. Can the gimble cause vibration at 1200 rpms and be ok at lower rpms or flywheel issue?

 

[starsnstripers]

Re: Gimble bad?

Good point Bruce, I also talked to Bondo today who said the same thing. I checked the coupler with a tool as it was idling and it slightly went up and down at the end of the coupler tube. Maybe like 3/32 not alot, but i thought may be enough to make it vibrate at 1200 rpms. I pulled the engine and whaalaa the flywheel is balanced and has a weight on it, grrrr. My own fault for using the 14" flywheel. I'm going to go back to the 12 3/4 flywheel and the other style coupler. Should get it back together tomorrow and try it again.I'll give an update on it. Also the noise was the exhaust flappers had a little wear on them and they were clattering intermitently. Bearing/U-joints seem fine.

 

[cannonford57]

Re: Gimble bad?

seems ya have already got your prob. handled but for future reference if you crank the steering full stop and the noise gets worse ,gimbal bearing time...jmo

 

[starsnstripers]

Re: Gimble bad?

Problem solved, put in a 14" flywheel with no weight. Smooth as silk.

 

[bruceb58]

Re: Gimble bad?

Good thing! The reason I knew about this was because my dad had a flywheel without balance weights installed on his 454 in a Suburban. It eventually led to his crankshaft breaking.