General maintenance help for a sterndrive noob

[metsfan3197843]

Let me start by noting that while I've been a boat owner for the better part of 20 years, this is my first sterndrive boat so go easy on me if I'm being a moron...

I Pulled my Drive off for the first time yesterday. The U-Joints had some surface rust on them, but are free and no slop. Having never pulled a sterndrive before, not sure if this is normal. The boat has been in saltwater it's whole life as far as I know. The bellows looks fine, no water inside at all. The drive clearly had not been off in some time. The grease on the drive shaft was dry as a bone and the engine coupler looks like its pretty worn. Gimbal bearing is starting to get rough so I'll change that out. Alignment bar slid right in and turns easy so if the coupler is worn it appears to be from lack of maintenance and not a bad alignment.

So I guess my questions are: Is it normal for there to be some surface rust on the U-joints or should I be concerned? Secondly, since I'm going to pull the motor to get a better look at and most likely replace the coupler, what else should I look at doing while everything is out?

 

[GA_Boater]

The rust is probably from a torn bellows sometime in the past. With no water in the bellows, that's a safe bet.

How do the u-joints feel for notchiness? Seeing signs of water in the past, they should be examined closely or replaced for piece of mind.

Are there signs of oil seepage around the yoke seal? One more thing to look at.

And with the drive off, do an impeller service and lube change with a pressure test.

I haven't had an I/O recently, but some maintenance items never change.

 

[metsfan3197843]

The rust is probably from a torn bellows sometime in the past. With no water in the bellows, that's a safe bet.

How do the u-joints feel for notchiness? Seeing signs of water in the past, they should be examined closely or replaced for piece of mind.

Are there signs of oil seepage around the yoke seal? One more thing to look at.

And with the drive off, do an impeller service and lube change with a pressure test.

I haven't had an I/O recently, but some maintenance items never change.

U-joints feel fine, real fluid movement. I'll give them a better look and also the yoke seal. Is it as simple as just removing the yoke ring nut with a spanner and pulling the yoke assembly out to replace the U-joints or is it more involved than that? I have the manual at home guess I better dig into it. Plan on doing a pressure test while the drive is off, but my raw water pump is engine mounted.

Thanks for the info

 

[harringtondav]

Love the engine stand. Clear that you know your way around a tool chest. My experience is with Alpha II drive shaft assys, but the process is the same.

Removing the castle retaining ring and pulling the assy is the easiest way to change your Unis. But first pressure test to see if the yoke shaft seal is leaking. You'll be 90% to changing the seal. To change the seal you'll remove the retaining nut on the yoke shaft, and the input gear and bearings will slip off as a pressed together unit. You'll need an inch/pound dial torque wrench to check & adjust the preload on these two bearings when you reassemble per your manual. You'll have to sneak up on tightening the nut, else you may over tighten above the rolling drag spec for used bearings. Then it's press everything apart and start over.

It's difficult to get a good visual on the coupler splines through the bell hsg and bellows. You'll have a better view once you pull the old gimbal brg. The tips of the spline teeth should be flat. If they are pointed, the spline is worn. Your coupler yoke shaft should have minimal rotational play in the coupler. With the gimbal brg. out, your alignment bar should also have very little rock. "Minimal" and "very little" are vague. Better known compared to a known good coupler.

The engine must come out to replace the coupler. If you suspect it is bad, go ahead and pull the engine. Also rear engine mounts and exhaust Y tube seal are relatively inexpensive, especially compared to the time and effort to get to them. Consider changing these also.

If you decide to replace your Unis, measure pull a cap on an old one and measure the trunion OD. Make sure your replacements are the same size. OEM merc and Sierra will be. Some Spicer, etc. will fit the yokes, but measure their trunion ODs before you install them. If they are smaller than the original, send them back and install Merc. or Sierra.

 

[GA_Boater]

Didn't see you have a Bravo drive in your full sig. And I tell peeps to read threads! :doh:

It's still a good idea to check the impeller if you don't know when it was changed. With sand and silt, it is a wear item and easier to check while the motor is out.


Don't know how easy or difficult it is to change the yoke seal, never had to do one.

 

[achris]

First up, you do not need to pull the yoke out of the drive to replace the unis... And you don't need to break one of the lugs of the cover nut either. :facepalm:

Click on the videos link at the bottom of my signature and you'll find a video on doing the rolling torque set up. It's not difficult, just fiddly...

Chris....

 

[metsfan3197843]

Thanks for the replies guys. Much appreciated. After closer inspection it does appear that there that the oil seal around the yoke is leaking, but I will pressure test to be sure once I round up the parts to put the tester together.

Also noticed on the shift cable bellows the clip on the drive end is missing... I suppose I better replace the cable if its been exposed to saltwater correct?

Too funny I had already stumbled across your video during while trying to figure out what I was getting into. Good video thanks for that!

 

[harringtondav]

Also noticed on the shift cable bellows the clip on the drive end is missing... I suppose I better replace the cable if its been exposed to saltwater correct?

That crimp clamp on the cable bellows helps keep water out of your bilge. Your bell housing-to-out drive gasket keeps water out of the cable.

I'll probably get beat up over this one, but I don't think that missing clamp will hurt anything unless you track a transom plate leak back to it. My Merc. manual shows special welded up pliers jaws to tighten that clamp just so. The shift cable needs to slide in and out of the bellows during trailer tilt, and normal trim tilt. Too tight, and the bellows can tear. So I'd work thru your know issues before worrying about that clamp.

 

[achris]

Just replace the missing clip with a cable tie doubled over....

 

[metsfan3197843]

Thanks guys, finally something that’s an easy fix. Been a rarity with this boat...

 

[metsfan3197843]

I'm thinking when the engine is out I should probably install the bravoitis fix. From what I understand it's not an if but a when kinda deal right? Is this the right kit?

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