U-joint grease, o-ring or no o-ring lower unit drive

[karbine98]

My first post for my first boat. Pulled sterndrive on my '78 Mercruiser 165 to check impeller and seals, etc. Wondered if the generic "Marine" grease is adequate for the u-joints and splines or only for the trailer wheel bearings. I'll have to drive a ways to get 2-4-C grease, but will if it is advisable. Also, I watched a video that said not to put o-ring on lower unit drive shaft since it will probably not stay in place when reassembling lower to upper and may mess up fluid flow. There wasn't one when I separated drive, but I did find a few pieces of an o-ring on the table later. This will undoubtedly be the first of many questions. Thanks in advance for any advice. Greg in Omaha

 

[CaptainMak]

Re: U-joint grease, o-ring or no o-ring lower unit drive

Greg,
I'd order the 2.4.C grease and wait a couple days to get it delivered right to my house along with the other stuff you'll need to replace. (o-rings, gasket, etc). But that's just me. I'd hate to ruin an outdrive just because I used something "in a hurry". Try your local NAPA, they might be able to get all this stuff same day. Around here they do.

What o-ring are you talking about when "reassembling lower to upper" ? Do you have a MERC manual ?? If the manual calls for it, install it. Don't always listen to videos. PM me if you need one for your engine.
BTW, I got a 1977 165. Talk about a work horse. Can't kill mine probably if I tried. :joyous:

 

[thumpar]

Re: U-joint grease, o-ring or no o-ring lower unit drive

The gurus on here have said many times that o-ring is not needed. I always left mine out. From what I have read it seems to cause more problems. I always just used marine grease everywhere so I didn't have to have multiple guns.

 

[wrench 3]

Re: U-joint grease, o-ring or no o-ring lower unit drive

For the splines where the drive shaft goes into engine coupler, you should use the special spline grease such as Mercruiser 92-81639A4 or Sierra 18-9200.

 

[achris]

Re: U-joint grease, o-ring or no o-ring lower unit drive

There is a service bulletin called for 2-4-C NOT to be used in bearings and unis. The reason is 2-4-C has teflon in it, and the balls or needles in the bearings will slide rather than roll, so use any good quality grease, or get the Merc grease specifically for unis and bearings. As for the 'O' ring... Do not put one on if you have the groove at top, you can run the risk of it flicking the seal up and allowing water into the spline, which corrodes them out in very short order.. Later shafts were machine without a groove. While you have the drive all apart, replace the lower seal in the top box. It's easy and cheap, and if it's more than a few years old, the exhaust gas has probably rotted it already.... Just flick it out with a screwdriver and install a new one. The part number is... 26-965031

Chris........

 

[Bondo]

Re: U-joint grease, o-ring or no o-ring lower unit drive

My first post for my first boat. Pulled sterndrive on my '78 Mercruiser 165 to check impeller and seals, etc. Wondered if the generic "Marine" grease is adequate for the u-joints and splines or only for the trailer wheel bearings. I'll have to drive a ways to get 2-4-C grease, but will if it is advisable. Also, I watched a video that said not to put o-ring on lower unit drive shaft since it will probably not stay in place when reassembling lower to upper and may mess up fluid flow. There wasn't one when I separated drive, but I did find a few pieces of an o-ring on the table later. This will undoubtedly be the first of many questions. Thanks in advance for any advice. Greg in Omaha

Ayuh,..... Please see the note below,....
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[achris]

Re: U-joint grease, o-ring or no o-ring lower unit drive

Found the bulletin...

http://www.boatfix.com/merc/bullet/94/94_13.PDF

Chris.......

 

[karbine98]

Re: U-joint grease, o-ring or no o-ring lower unit drive

The quality and speed of the responses has certainly exceeded my expectations. Thanks for all the tips and pointers. I ordered the lower seal as suggested by "achris" and ordered the Merc spline grease and a tube of 2-4-C for prop splines. Maybe didn't need both, but hey I can use anything leftover on the tractor pto, etc.
We love our very "retro" '78 SeaStar Spoiler 888. At the launches last year amidst a lot of beautiful, high dollar boats this old pale green metal flake throwback got most of the attention. Park rangers even came over to check it out.

 

[wrench 3]

Re: U-joint grease, o-ring or no o-ring lower unit drive

We love our very "retro" '78 SeaStar Spoiler 888. At the launches last year amidst a lot of beautiful, high dollar boats this old pale green metal flake throwback got most of the attention. Park rangers even came over to check it out.

Our last boat was a 1976 22' Mason cuddy with a hardtop. It's styling reminded me of a PT boat. At the docks some one was always commenting on it. I kind of miss the attention now that we traded up to a 1986.

 

[karbine98]

Re: U-joint grease, o-ring or no o-ring lower unit drive

PT Boat was my first impression of the profile of our boat. Really like the clean lines. I have a nice naval style black powder cannon with 24" barrel and attractive wood rig. It sure would look nice on the bow of our Spoiler.

 

[ziggy]

Re: U-joint grease, o-ring or no o-ring lower unit drive

fwiw. and agreeing with what's already been stated.
i don't use the oring on the drive shaft in the lower in years. no ramifications.
i have three greases on hand.
2-4-c
ujoint and gimble brg grease
and spline grease.
i use them in there proper places.
i use merc 25w-40

it's just easy to use the proper merc lubs.
i've not needed any other lubs while servicing the boat in my sig. them cover it all so far.

 

[karbine98]

Re: U-joint grease, o-ring or no o-ring lower unit drive

Chris you are a genius, scholar, gentleman! I popped out that lower seal and voila, up inside the female splined receptacle was a chunk of the o-ring that's not supposed to be installed in the first place, along with the coiled wire o-ring insert from the inside of the old seal. It was broken and quite tangled. Could the pieces of lower unit drive shaft o-ring and the coiled wire o-ring have allowed water to get into my gear lube? Also Chris, when I installed the new seal, I used a piece of wood dowel to tap it into place. I pushed it all the way into the receptacle so that the grooved side of the seal fit down over the circular, tubular structure enclosing the female receptacle for the lower drive shaft. Does my question make any sense? Was it correct to push the seal in all the way? Your advice greatly respected and appreciated. Another question, when reinstalling sterndrive do I really need to use contact cement on the o-ring around the water inlet on the bell housing and on the large rubber ring that goes on the sterndrive gear housing. Thanks, Greg from Omaha. PS: you ever make it to Nebraska I'll treat you to the best beef steak in the world!

 

[achris]

Re: U-joint grease, o-ring or no o-ring lower unit drive

The leaking lower seal shouldn't let water into the drive oil, there is another seal above that one.

When I install a new seal I use a large socket, inverted, that clears the upper drive shaft and will push the seal in so it's flush with the housing. I also use a little Loctite 515 on the outer flange of the seal.

On the bell housing, I use contact adhesive on the large rubber ring, but just a bit of grease to hold the water 'O' ring in place... Doesn't really matter if you used adhesive on the water 'O' ring... But it's well advised to use it on the big rubber ring.

Cheers....

And I may hold you to that steak ... (And it's going to need to be pretty damn good to beat an Australia steak... )

 

[karbine98]

Re: U-joint grease, o-ring or no o-ring lower unit drive

Thnx Chris. So should I pull my seal back up out of the opening it went into and just have it even with the lower, larger opening leading to the female receptacle for the lower drive shaft? How bad is my nomenclature for the structures/parts, etc? Greg

 

[achris]

Re: U-joint grease, o-ring or no o-ring lower unit drive

Thnx Chris. So should I pull my seal back up out of the opening it went into and just have it even with the lower, larger opening leading to the female receptacle for the lower drive shaft? How bad is my nomenclature for the structures/parts, etc? Greg

It's understandable, so it's fine.

I suspect trying to pull the seal up will distort it. In that case, pull it all the way out and fit a new one... A new seal is not expensive. A new drive-shaft is....

Chris.....

 

[karbine98]

Re: U-joint grease, o-ring or no o-ring lower unit drive

I suppose I should say "should I pull the seal back down" in as much as I'm looking at underside of the upper case for the lower seal. It must be aggravating trying to talk newbies through some (all) of these repairs. I would like to send a picture I took but am on the computer in the OR doing a spinal fusion right now and can't sync my phone. I know looks can be deceiving, but my MC-1 looks so much better than so many I see on Youtube. Guess boats must be a lot like women--sometimes nice on the outside, but a bit worn and rusty on the inside. Again, thnx for all the great help. Greg