1991 4.3l omc cobra vibration

[ruggles]

Hi my boat vibrates when taking off and its quite pronounced at lower rpms. I'll be dropping the drive this spring to replace the shift cable and I'd like to know how and what to check while I'm in there. I'm planning on buying the shift cable tools and the alignment tool. The background is that I bought it off a guy who had hit some rocks and chewed up his stainless prop. We checked outthe prop shaft and it looks true. Please let me know what other things it could be. Bad motor mount, bad alignment, ujoints?

Thanks!

 

[dannys2004glastron175mx]

Check your gimbal bearing .

 

[bruceb58]

And u joints.

 

[ruggles]

thanks guys. any tips on how to check them and what to look for? I am mechanically inclined but I am new to sterndrive technology.

 

[bruceb58]

You can turn and feel gimbal bearing. U-joints are a little tougher because something that feels smooth may be bad when under torque.

 

[ruggles]

I am going to tackle this job starting this Saturday. I have been unable to source an alignment tool or the shift cable tools locally (I'll have to make these myself). I am concerned the vibration is from a misalignment of the drive. Hopefully a local shop will lend me the alignment tool or do the alignment without bending me over. It's hard to find any help in a small town in Canada. I'll be posting my issues (im sure I'll have many) as I go and I appreciate all the help I have received so far.

 

[Speak]

Order your tools on line. I did. I live in a small Canadian town too. Search midnight wolf, he supplies them 40 bucks for the cable tools. Cheap man.

 

[ruggles]

it'll take 2 weeks to get here though. I talked to him last week. It was my fault for not ordering them earlier. I've booked the next week off months ago so Im going into it as is. Heading to Gibsons on the Sunshine Coast on saturday. I can make the shift tools but the alignment one I can't. Hopefully a local marine shop has one I can borrow.

 

[ruggles]

rained and Its like green goo and black. I loosened the drive first before draining the leg but I don't think that should matter. I bought u joints just in case but I guess I need bellows too? the last record of the oil being charged was 2011! The guy told me it was last year but now I'm thinking he was full of ****. The oil wasn't even showing on the dipstick. Maybe this was the cause of the vibrations ans shifting issues?