Outdrive Valve Assembly?

[andrewterri]

Pulled my gen 2 drive and oil came out of plastic nipple on the starboard side that is between the top two studs. It looks like drive oil is in drive bellows as well. There was grease on the housing the drive yoke is attached to and im guessing that was part of the factory install. Thinking by the amount of oil in bellows it did not leak out of that plastic valve. When I looked at the diagram it is listed as valve assembly with part number 18920A1. What is this? Best I can tell the remote gear lube bottle connects by the shift shaft. The boat has became like a thousand needle picks. The more I do the 3 year maintenance the more little issues that pop up.

 

[achris]

That's a poppet valve, and it is the path to the monitor bottle. And yes, sometimes they leak when the drive is removed. It's no big deal because it's open anyway when the drive's in place.

The oil in the bellows IS an issue. It means the big seal at the front of the drive is leaking. Only one solution, open up the drive-shaft housing and fix it (new seal and speedie-sleeve the yoke).... It's not a big job if it doesn't escalate.

Chris......

 

[andrewterri]

Thank you Chris. Would it be the oil seal in front of the carrier bearing? When I replace whatever seal is leaking (I am searching forum post's now) would I need to preload the bearing?

 

[Bt Doctur]

usually yes, but it also depends on the gearset used. the manual lists the procedure.

 

[Bt Doctur]

http://www.boatfix.com/merc/Servmanl/14/14a3.pdf

 

[andrewterri]

Thank you for the manual Bt Doctur.

 

[harringtondav]

Pick on Chris' "My Videos" at the bottom of his signature. He has a good vid on setting/checking preload. You don't need to disassemble the two bearings to replace the yoke seal, unless you want to inspect them. Remove the lock nut and the gear/bearing/seal assembly slides off the yoke shaft.

Also you can cheat if the yoke shaft's seal surface has a groove. Shim the seal driver .040"/1mm when you press the new seal in. This will place the seal's lips on virgin seal surface. Don't forget to place the seal's garter spring toward the gear, away from the seal carrier's O ring shoulder. I just finished installing this seal after I put it in backwards last year. This will cause lube to ooze into the driveshaft bellows.

 

[andrewterri]

Think I just got lucky. When pricing the parts with a reputable mercruiser dealer he told me If i bring them the upper they will replace the seal for less than 100 dollars. That almost cheaper than i can get the bench vice, torque wrench (mine will not go below 20 ft.lbs.), and wrench for retainer but for let alone the actual seal. I am about to split the drive. I can not remember for the life of me, I have to drain the gear lube before splitting the upper and lower correct?

 

[achris]

You can split it undrained, but it's going to be messy! Drain it first!

 

[andrewterri]

Thank you Chris. I got it drained and took it to dealer but kinda of wished I would have kept it and done it myself. Just came down to money. They told me if I bring in the lower they can pressure test to make sure there is not another leak but it will cost another hour labor, $100. They said they could not warranty if they didn't test it. Trying to decide if I want to make the 4 hour round trip. No water in oil so I don't think there is another leak. If they work with me and schedule it where I drop it off they test and reassemble than I take it home it wont be to bad. It will be nice peace of mind, but I guess it comes down to how much that piece of mind is worth.

 

[achris]

.... It will be nice peace of mind, but I guess it comes down to how much that piece of mind is worth.

Hedging your bets?

Watch out for any "oh, we found....." Likely be, "we found the yoke is grooved, and that's why the seal's leaking".. Yeah, they do that, just set the seal 40 thou deeper (as Dave suggested), and that's the problem solved. They'll likely try to sell you a new yoke, and all the labour involved with that.... BTW, an hour to pressure test? Are you kidding me! That is a 3 minute job. Screw in the pressure gauge and pump it up with air, close the valve (to the gauge) and walk away and finish another job. 15 minutes later, look at the gauge.... That's it.

Chris.........

 

[andrewterri]

I thought is was a 15 minute test but was not sure enough to call them out without look it up. Will not take 45 minutes to reassemble drive. I likely would not have scored the yoke this soon would I? When I opened the vent for gear oil there was some pretty good pressure that blew out with oil. Some how if there was too much oil it could not have just pushed passed the seal and not damaged it could it?

 

[achris]

With the monitor bottle, those drive are designed to be 'fully flooded'. And the seal is facing inwards, the higher the pressure, the tighter the seal.

If you include assembling the drive halves, then add another 10 minutes. For the '15 minute' test, you don't need to be there looking at it for 15 minutes. I usually set the test up and go and do something else in that 15 minutes. You can achieve plenty in 15 minutes. A quick workshop tidy-up, an oil drain and refill on a small outboard, a compression test on a V6, etc, etc....

Chris.......

 

[andrewterri]

Chris, do you think it needs to be leak tested?

 

[altitude 411]

I don't mean to but-in but may I suggest you go to your local hardware store and get a gauge and some hose/fittings and build a pressure tester yourself for the price of gas of your return trip to the dealer. Very simple to do, especially if you have gauge in the shed. Old bicycle pump? You can then have piece of mind and be able to check your drive each season. This one cost me around twenty bucks for fittings & hose. I just borrowed the gauge off my fuel pressure tester and used a Presta valve stem from an old bicycle inner tube on one end and the plastic gear oil fill fitting on the other...

 

[andrewterri]

Thank you guys for the help and guidance. I am just going to pick up the upper when they are dong and pressure test it myself. I have a pressure test set up for setting pop-off pressure on our seadoo carb's. I can figure out a way to make that work and report back if it is not holding pressure. I have seen to many bad mechanics to trust someone i have no experience with. this shop just has a good rep. Shop I went to before this one for a quote i was told to talk to the guy that works on drives. In walks a 16 yo kid. I told him what my problem was and he said he would have to look at it to see what seal i was talking about (carrier bearing seal). i told him if he had merc service manual #14 i could show him. He said he does not have any manuals but he has done many drives and just knows how they go. I asked him about pre loading the bearing and again he said he would have to get in there to see what i was talking about. It got worse but i think you guys got the idea that there was no way he was working on anything on my boat.