Vibration When Turning Sharply

[greg82255]

Hello,

I have a 1986 Merc 260/Alpha One on my Formula. I've started to notice some vibration when I turn the steering wheel all the way left or right. I have only noticed this at idle because I haven't tried to turn too hard while at speed. I've done some research and it appears that the problem could be the u-joints or the gimbal bearing, but my question is how to check the u-joints? I know to look for play in the gimbal bearing and to check the alignment, but is there anything I am missing here? what else should I be looking for? Also, can I get through the end of the season (which is only about 6 weeks) before I start taking things apart? Thanks in advance

 

[Bondo]

Re: Vibration When Turning Sharply

but my question is how to check the u-joints?

Ayuh,... The only way to truly check 'em is to pull the bearing caps, 'n look for ridges on the crosses...

Odds are, it'll make it 6 weeks, but those are Your dice to roll....

 

[greg82255]

Re: Vibration When Turning Sharply

I'm going to have the boat out of the water next week for a few days. I could check them then. How easy/time consuming is it to replace the u-joints? Can it be done in a few hours?

 

[90stingray]

Re: Vibration When Turning Sharply

If you have the right tools, parts, and knowledge ... a few hours is do-able.

 

[Kaplooi]

Re: Vibration When Turning Sharply

You have to pull the drive off to access the u-joints since they sit between the engine and drive inside the u-joint bellows. Pulling the drive isn't a huge deal, but you will likely need to remove the shaft from the outdrive to have enough access to change out both joints and that requires a specialty wrench. Also, you may need a hydraulic press to push the u-joints out of their yokes and the new ones in. You also need snap ring pliers if I remember correctly. Bond-o is referring to doing all the above things to access the old joints and then pulling off the bearing caps to check the needle bearings in the 2 crosses for damage/wear. IMO, if you're going to go to all that trouble you might as well just replace both joints.

From what I understand gimbal bearings usually start to growl rather than vibrate when they start to go so you can try just redoing your alignment and making sure the bearing is greased up. Replacing the gimbal bearing by the book requires a specialty puller that costs around $260, but I was able to use some threaded rod stock with some fat washers and a couple blocks of wood to make a crude but effective puller. The trick to using that is you have to thread a nut onto the rod behind the engine, which may or may not be doable depending on what kind of access you have. In my case I was rebuilding my entire interior at the time so I had the engine out and the transom plate sitting on my bench so access was not an issue.

 

[greg82255]

Re: Vibration When Turning Sharply

I've never done the u-joints before and I don't think I have the tools to do it. How much would a dealer charge to replace them? The gimbal bearing I can do myself - it doesn't seem like a hard job and I have access to a slide hammer to get the bearing out.