Top gimbal bearing o-ring on drive shaft sheered off?

[void7910]

Hey all. I was re-installing my alpha one gen 2, on my second attempt after having the paper gasket pop out. Anyway, I noticed to top most o-ring (closest to drive) had an entire section sheered off all the way around. It was like a thin o-ring was cut off it and just hanging out on the top bit of the shaft. Replaced that one o-ring, rest looked fine and were just installed on my first attempt at install. Any idea idea what caused that o-ring to fail like that?

 

[Bt Doctur]

The large square O ring is installed with bellows adhes, weatherstrip adhesive, or contact cement in the housing first. If dislodged water can enter the drive

 

[void7910]

This wasn’t the big o-ring. second small o-ring on the drive shaft.

 

[dubs283]

If its the o ring closest to the u joints thats one of the two gimbal bearing o rings used as dampeners between the gimbal bearing race and splined input shaft

Shearing it off isn't too big a deal but it could indicate a misaligned gimbal bearing or too large o.d. of the o rings

Light grease or oil helps them slide better through the race at drive install

 

[void7910]

I’m a bad boat owner and didn’t check alignment before both install attempts. However, no major issues getting it on or off once I get the splines aligned after a couple attempts.

Interesting about OD. It was a legit Mercruiser kit so I assume things were the right size. Both gimbal o-rings looked about the same and only one broke.

My only other thought is that it was some kind of a weird manufacturing error. Maybe existing rubber stuck in the mold or something.

 

[crazy charlie]

I’m a bad boat owner and didn’t check alignment before both install attempts. However, no major issues getting it on or off once I get the splines aligned after a couple attempts.

Interesting about OD. It was a legit Mercruiser kit so I assume things were the right size. Both gimbal o-rings looked about the same and only one broke.

My only other thought is that it was some kind of a weird manufacturing error. Maybe existing rubber stuck in the mold or something.

I have had mercruiser outdrives for over 30 years and never had that happen on any o rings.If you are going to replace o ring and reinstall ,I would recommend getting a glob of grease on 2 fingers and reaching into the bell housing and smearing some grease onto the surface of the gimbal bearing casing.not a fix but a possible precaution only.You can also grease the rings and make sure you grease the splines. Charlie

 

[void7910]

I have had mercruiser outdrives for over 30 years and never had that happen on any o rings.If you are going to replace o ring and reinstall ,I would recommend getting a glob of grease on 2 fingers and reaching into the bell housing and smearing some grease onto the surface of the gimbal bearing casing.not a fix but a possible precaution only.You can also grease the rings and make sure you grease the splines. Charlie

Good idea about greasing the contact points of the gimbal. Definitely greased everything else, o-rings, splines, big o-ring, u-joint middle section, front of drive that goes into bell housing.

I also have never seen an o-ring come apart like that. Took me a while to figure out where this little thin o-ring came from before I notice a strip out of one of the gimbal o-rings all the way around.