Driveshaft/Carbon Seal Questions

[bakersboas]

Clearly I need an engine alignment is my first thought. What else would cause the carbon ring and drive shaft to look this way (egg shaped) other than the engine alignment being way off? Would revving the engine for a long period of time while cavitating cause this too? Or possibly running the engine without water?

Do you think I might as well change the drive shaft too?

Thanks in advance.

 

[Mister Magoo]

Well since no one else is going to chime in I might as well. It seems to me that alignment is between the pump support/pump and the engine. The carbon ring is held into place by the rubber boot, it floats. Seems to me that the rubber boots tend to lose elasticity and sag, which, causes the carbon seal not to push against support ring. On the carbon seal/boot/support ring I just changed I could push the boot rearward of the boat and it would stay there and not rebound to meet the support ring. The rubber boot was not holding the carbon ring correctly. Seems that if the engine was misaligned you would have some kind of wear pattern on the shaft splines. Just my 2 cents.

real good thread on green hulk with videos of a wobbling carbon seal.

http://greenhulk.net/forums/showthread.php?t=284357&highlight=drive+shaft

 

[FlyboyX]

My thought is that this engine was probably run on the trailer for a very long time. You are only supposed to run the boat out of the water for a couple minutes at a time because that seal isn’t getting any cooling from lake water. It looks very overheated to me. In fact I’ve never seen one in that bad of shape.

along the lines of what mr Magoo said, I think perhaps overheating the carbon ring would potentially melt the rubber boot as well.

Two years ago, I had my port driveshaft out of my boat. While I was in there, I ran the carbon ring’s opposite contact surface(The round metal part on the driveshaft) on the buffing wheel and polished its contact point to a mirror surface. It seems to have done well for the contact surface of the carbon as well as making a better seal.

 

[Mister Magoo]

I got my 13 year old boat last year with 26 hours on it. It was owned by a family that did not use it much but who knows how they ran it.. It leaked about a gallon in total each outing. It was coming from the carbon seal area, seems to leak right after starting for the first time and then would not leak. I just changed the carbon seal/support ring/bellows. The old bellows was wore out and sagging down with caused the carbon seal to wear towards the top. As soon as it stops raining I'm going to water test.

 

[FlyboyX]

Does your boat have a Hobbs meter? How were you able to determine how many hours it had?

 

[Mister Magoo]

The ECU had 26 hours and the cluster had 22 when read with a Candoo scanner. Both of those parts have time and date stamps/labels on them that would indicate that both are original parts.

 

[CSager]

I ran mine into the shop with everything out so they could make sure it was spot on. Only took 20 minutes. My shaft was rough and caused some leak issues. It should be smooth, it does look like the carbon seal was overheated. If you have everything out check the bellows bearing, replace the drive shaft and do the carbon ring. I chased some leaks and cavitation for a few years until I replaced worn parts. Now things are good, the shaft was a little pricey but the others weren’t to bad.