Alpha Drive Re-sealing - What interval?

[qystan]

Intent is to see if preventive periodic re-sealing can be put into the maintenance routine. <br /><br />Typically I see users operate until the seals give and then look to changing the seals. Hopefully they don't kill the bearings and gears in the process and its major bucks.<br /><br />What are your experiences on this? How many hours or days/months can you get out of a set of seals, exclude accidents and fishing lines. <br /><br />Hate the idea of waiting for it to happen, inevitably it'll happen at the worst of times.

 

[achris]

Re: Alpha Drive Re-sealing - What interval?

Qystan,<br /><br />I have almost 900 hours on my 1994 Gen II leg and had to put a new seal at the front of the top box about 6 months ago. The main problem is not the seals but the surfaces they run on. My gear-end yoke has a groove worn into it. I have mounted the new seal about 1/2 mm deeper to get it to run on a 'new' surface, but the next time it'll be a re-surface job. I expect that in the next year or two I will be pulling both boxes down and re-surfacing all seal surfaces.<br /><br />I guess the simple answer to your question is more to do with hours run than years old.<br /><br />I'll bet you're totally confused now. <br /><br />Chris...............

 

[Chris1956]

Re: Alpha Drive Re-sealing - What interval?

Qystan, There are seals on the outdrive that are very easy to change, and some that are hard to change. The easy ones are waterpump base oring and base gasket, upper-to-lower gearcase oil seal, upper drive shaft seal and waterpump base driveshaft seal. All but the waterpump base driveshaft seal come in the impeller replacement kits. I recommend you replace these easy seals whenever you replace the impeller. Likewise the water intake, outdrive mounting gasket and (Alpha 1 Gen II) gear oil seal should be replaced every time you pull the outdrive.

 

[Chris1956]

Re: Alpha Drive Re-sealing - What interval?

I forgot the rest of the seals. If you see some water in the gear oil, first replace the waterpump base seals (just replace the base itself, the seals come with it). The job is as easy as an impeller job, and is usually the culprit. If that doesn't fix it, the shift shaft and prop shaft seals are much harder to replace. Time to get some professional help!

 

[qystan]

Re: Alpha Drive Re-sealing - What interval?

Achris<br /><br />You are right, its running time. 900 hours is a good long time. I suppose that would be good for at least 2-3 years of use. For me, that would be many more. My use only average 10 hrs a month, maybe less. Small place, longer run would get me arrest for illegal entry into neighbouring countries. In 2-3 years, I would have pulled the unit for teardown insp and corrosion cleanup. I would be alright as the seals would be changed. For me, calendar time (read as corrosion build time) is my main driver.<br /><br />Had the same yoke problem early this year, new yoke, seals and bearings in the upper unit. Now into the lower unit. The rate things are going, only the housings would be original and my bank account would bear no semblance to anything civil.<br /><br />Chris<br />Thanks for the info on the waterpump base being the main culprit, this is really useful info and yes, it is an easy one. The shiftshaft isn't difficult, just that a tool is needed and can be made quite easily. Its aluminium, if I had known aluminium is good enough, would have taken a file to the job. Bought that, the machine shops' premium charge for a once-off job is close to Merc's price. <br /><br />The baddie is the carrier seals. The carrier is usually corroded into place. With Mercstuff's removal method using propeller, I think removal isn't too bad, have not personally tried it yet. Last try was with a puller, broke the carrier...damn! <br /><br />As a practice, I too never reuse seals or gaskets. Unfortunately some mechanics believe that a visual inspection can determine reuseability.