SX-M lower unit issues

[rossbar86]

Hey everybody, I have a 2001 Larson SEI 186 with a Volvo Penta 4.3GL and SX-M outdrive.

I had it in the shop to have a fuel leak addressed and received the following message from the mechanic..."While water testing the Larson, roughly 15 minutes into the test, I began to hear a growling noise while on plane. We turned back to head towards the boat ramp and reduced speed. Shortly before getting to the boat ramp vibration began to occur. at this point brought the boat off plane and slowly brought it back to the ramp. After loading the boat onto the trailer inspected drive. Found that the prop shaft has excessive play. Brought the boat back to the shop and drained the fluid out of the outdrive and found it to have heavy water contamination. The drive seems to have had a seal failure which brought water into the lower unit. It is likely that a bearing inside the lower unit has failed due to water contamination. I recommend rebuilding or replacing the lower unit."

I was quoted $5,500 for a replacement and I just can't afford to put that into a boat I initially paid $7,500 for. I am curious if anybody has addressed similar issues themselves and/or has any idea what bearing this could likely be? I like to think I may be able to fix this myself with enough patience and guidance.

Thanks!

 

[Horigan]

If I were in your shoes, I would buy a used one for about half that price. I would replace the complete drive (sans transom mount), not just the lower, since the failed bearing material has flowed through the entire drive and likely damaging most of the gears and bearings.

Have you been doing yearly oil changes? If so, that should have found the leak earlier and prevented the damage.

 

[rossbar86]

If I were in your shoes, I would buy a used one for about half that price. I would replace the complete drive (sans transom mount), not just the lower, since the failed bearing material has flowed through the entire drive and likely damaging most of the gears and bearings.

Have you been doing yearly oil changes? If so, that should have found the leak earlier and prevented the damage.

Thank you for your input. I have been getting yearly engine oil changes as part of the winterization, but in hindsight I don't think the mechanic was changing the gear lube every year. I only recently learned that should be changed annually after investigating this damage. In hindsight, I wish I had of just learned to winterize on my own and done the gear lube myself as part of the annual maintenance. It sounds like if I had caught it earlier, I would probably have just needed a seal replacement.

 

[Lou C]

To paraphrase President Regan trust but verify.
Before doing anything check the gear oil yourself unless they already dumped it. If there’s that much water in it that will be obvious. If so then they could be right. If not I’d pull the drive and check the gimble bearing & ujoints. The problem described could easily be a case of a bad driveshaft bellows and water could have corroded the gimble bearing & ujoints.
Not only should the gear oil be changed yearly but the drive should be pulled to check for water in the bellows. This is recommended by all sterndrive manufacturers and not doing so will lead to problems. I’ve been running the same OMC Cobra drive & despite salt water use it’s held up well because the maintenance was always done. When the bellows starts to show small cracks in the folds it’s time to replace it. I get about 10 years from a bellows.

 

[rossbar86]

To paraphrase President Regan trust but verify.
Before doing anything check the gear oil yourself unless they already dumped it. If there’s that much water in it that will be obvious. If so then they could be right. If not I’d pull the drive and check the gimble bearing & ujoints. The problem described could easily be a case of a bad driveshaft bellows and water could have corroded the gimble bearing & ujoints.
Not only should the gear oil be changed yearly but the drive should be pulled to check for water in the bellows. This is recommended by all sterndrive manufacturers and not doing so will lead to problems. I’ve been running the same OMC Cobra drive & despite salt water use it’s held up well because the maintenance was always done. When the bellows starts to show small cracks in the folds it’s time to replace it. I get about 10 years from a bellows.

Thank you for your response. Yes, they already drained the oil. I realize if the oil was milky that means at least a seal failure. Could the growling and vibrations still have been from u-joints ? Maybe multiple issues? I feel like it'd be an easier repair if the gimble bearing and bellows need to be replaced vs more serious outdrive repairs?

 

[Lou C]

Yes that could definitely due to a bad gimble bearing or ujoints. Spin the prop shaft with the gear case in neutral and see if you hear odd noises or play in the prop shaft bearings.

 

[BRICH1260]

In a pinch you could just replace the bad seal refill with oil and try to get another season out of it. I would check the drive oil periodically through the season to see if the water intrusion persists. If so, then you know you will have to replace or rebuild the entire unit. A pressure and vacuum test will confirm if still bad. I would pull the drive and replace the gimble bearing and bellows now. Maybe you will get lucky and will not have to replace the entire unit. But from now on, plan on pulling the drive for inspection and changing the drive oil annually. Good luck with it.

 

[Lou C]

The other thing you can do is learn how to at least do a pressure test to verify that there is a seal leak. Getting milky oil is not a death sentence to an outdrive as long as it's caught on time.
I had this one year on my OMC Cobra and I had it resealed and it's been fine ever since (and that, was 19 years ago!) It can be as simple as leaky drain and fill plug gaskets, or a prop shaft seal, these are normal maintenance items.
If you learn how to maintain it yourself you'll be far ahead and can avoid problems.
The other thing that will tip you off to worn bearings or gears is a lot of metal particles on the drain plug (magnetic) normally there is just a slight fuzz on them but if you see big chunks that's bad.

 

[rossbar86]

Yes that could definitely due to a bad gimble bearing or ujoints. Spin the prop shaft with the gear case in neutral and see if you hear odd noises or play in the prop shaft bearings.

Sorry, been out of town and off the forum for a couple weeks. Thank you for your response and suggestions!

 

[rossbar86]

In a pinch you could just replace the bad seal refill with oil and try to get another season out of it. I would check the drive oil periodically through the season to see if the water intrusion persists. If so, then you know you will have to replace or rebuild the entire unit. A pressure and vacuum test will confirm if still bad. I would pull the drive and replace the gimble bearing and bellows now. Maybe you will get lucky and will not have to replace the entire unit. But from now on, plan on pulling the drive for inspection and changing the drive oil annually. Good luck with it.

Sorry, been out of town and off the forum for a couple weeks. Thank you for your response and suggestions!

 

[Lou C]

Also be careful with buying used drives, unless the sellers are reliable, have a guarantee that they will stand behind and you have time to run the boat before the warrantee expires to make sure it's OK, I would spend the extra dough for a reman with a good warrantee, from as local a place, as you can find. I will buy things like transom assemblies, trim cylinders used, etc, but an outdrive, there is just too much that can be wrong, that you won't know, unless you have that time to run it under some warrantee. Yes you can listen to it bolted to the boat at idle, but unless you run it in the water, under load, then check for water intrusion (pull bottom plug after running) you really are gambling, and Volvo drives are expensive to repair. That's just a fact of boating life, they are stronger an Alpha and shift smoother, but they cost close to 2x the price to rebuild. Like a Bravo more so.

 

[rossbar86]

Also be careful with buying used drives, unless the sellers are reliable, have a guarantee that they will stand behind and you have time to run the boat before the warrantee expires to make sure it's OK, I would spend the extra dough for a reman with a good warrantee, from as local a place, as you can find. I will buy things like transom assemblies, trim cylinders used, etc, but an outdrive, there is just too much that can be wrong, that you won't know, unless you have that time to run it under some warrantee. Yes you can listen to it bolted to the boat at idle, but unless you run it in the water, under load, then check for water intrusion (pull bottom plug after running) you really are gambling, and Volvo drives are expensive to repair. That's just a fact of boating life, they are stronger an Alpha and shift smoother, but they cost close to 2x the price to rebuild. Like a Bravo more so.

Thank you for the tip, that makes sense