Volvo SX: Yoke O-ring size

[johnbo]

Hi, <br /><br />First I want to thank everyone for the assistance that they've provided over the past month or so, while I built up the courage and knowledge to tackle some overdue maintenance on my first boat.<br /><br />A couple of weeks ago, I pulled the outdrive, found a few things that had to be done and ordered some parts. Fast forward two weeks (business trip to Europe) and all of the parts are ready. Spent a long Saturday (jet lag and all) putting everything back together. (U-joints, gimbal, bellows, eccentric shaft seal, new gear oil, etc)<br /><br />The only surprise that I ran into was that the pair of O-rings that go on the input shaft (yoke), seemed to be a different size. I ended up with three sets of these O-rings, just because of the packaging of some of the parts that I ordered. All appear to be the same size, but they appear to be about 1/4" too small in diameter to fit in the grooves on the shaft. <br /><br />Because my drive is one of these Cobra labeled Volvo SX units, I checked with the parts diagram at DougRussell (one of my parts supplier) for both the OMC drive and the Volvo drive. While the index numbers on the fiche are different, they both point at the same (Volvo) part number.<br /><br />In the end, I did not replace these O-rings, but I'm left a little puzzled. I've never seen an application in which it would stretch an O-ring from its resting shape. <br /><br />I guess that I'm not so worried about not replacing the O-rings, this time. But, I don't understand why they didn't fit.<br /><br />Any thoughts?<br /><br />Thanks,<br /><br /> johnbo

 

[Don S]

Re: Volvo SX: Yoke O-ring size

That's the way they fit. Merc, OMC, & Volvo all use the same size oring.

 

[johnbo]

Re: Volvo SX: Yoke O-ring size

Thanks Don. It just seemed odd, but what do I know. I'll put the new ones in this fall, when I pull the outdrive for the end of season cleanup and winterizing.<br /><br />Thanks,<br /><br /> johnbo

 

[rodbolt]

Re: Volvo SX: Yoke O-ring size

those orings are to keep the shaft from chattering in the bearing.<br />they also assist in making the bearing turn with the shaft.<br /> if they made the shaft large enough to fit the bearing ID you would encounter difficulties when ya try to remove the unit.

 

[johnbo]

Re: Volvo SX: Yoke O-ring size

Hi rodbolt,<br /><br />I think that you were guessing that I left out the O-rings. I left the old ones in place, as I never remove a part until I have the (proper) replacement in front of me. Old habits from working on British sports cars die hard.<br /><br />I reconized the need for the O-Rings, I just didn't recognize that the new ones had to be stretched to fit. <br /><br />Thanks for your concern,<br /><br />johnbo