Vibration when turning

[ranger481vs]

I just bought a used Bryant runabout. My only other boat was an outboard, so the I/O engine is a new thing for me to get used to. I believe I made my first significant mistake. I had The motor trimmed all the way up via the "trailer" trim button when I launched the boat. I proceeded to start the engine, and probably back the boat out from the dock before trimming it down. Then, I noticed if vibration when turning. Wondering if I damaged the gimbal bearing and or u-joints or both? Any thoughts on this situation?

 

[ranger481vs]

In addition to the above, will I do more damage if I drive the boat again or is it okay to take a boating trip or two before fixing? Thanks in advance for any help.

 

[tpenfield]

:welcome:

You will feel a vibration when the outdrive is running in the tilt position as you indicated. If the outdrive seems to operate fine in the normal (down in the trim range) position., then don't worry about it.

It may shorten the life of the u-joints, but 1 instance of running in the tilt position is not going to destroy the u-joints.

Don't do it again

 

[ranger481vs]

Thank you. When I trimmed it all the way down, I was still feeling the vibration. So, I assume something will need to be replaced. Do you think the gimbal bearing is the likely culprit? I looked up how to replace that, and it looks like a very manageable repair that I can do.

 

[wahlejim]

That is a symptom of a gimbal bearing needing replacement, can also be u-joints, but I doubt that it was from that one instance. It is likely that the Previous Owner (often referred to as the PO on this forum) probably knew about the problem when he sold it. Is it ok to run it a couple of times before you fix it? That is the whole risk/reward debate. It could be ok, but it also could get a lot worse and take out more items if you have a catastrophic failure at WOT.

Since it is a new to you boat, it is best to do a lot of PM items on it so you have a baseline of when the work was done, unless you have documentation of the following being done recently:

-fresh water impeller/pump
-bellows
-gimbal bearing
-inspect u-joints for rust/play
-change lower unit gear lube (if old lube is milky, pressure test the outdrive for leaks)
-change engine oil
-spark plugs
-compression test (always good to know where you start so you can track it as time goes on)
-clean all electrical connections to shiny metal, even if they 'look good' (I would say that the vast majority of electrical issues people run into can be solved with a good cleaning)

Everything above is manageable by yourself and if you run into issues, we are here to help. To start with, list your engine, year, outdrive, all with serial numbers to get the most accurate advise.

 

[ranger481vs]

Definitely appreciate the help! When we test drove it, they were No issues present. The engine and steering ran very smoothly. Anyhow, it's a 1996 mercruiser serial #s
Engine: 0f77821
Transom: 0f668076
Drive: 0f693736

Alpha 1: 0f668076

 

[Rick Stephens]

I consider it a half hour job to remove, inspect and grease ujoint and gimbal bearing and replace the outdrive on a Gen 2. Well worth the effort in your case with a new to you boat.

Lower the drive to almost touch ground, put gear lever in forward, 6 nuts, the pin on the tilt rams and the speedometer hose and off comes the drive.

See if there is any water or oil in the bellows. Grease up the ujoints. Spin the gimbal and see if it is tight and perfectly smooth turning. I'd recommend checking alignment since this is first time in for you. Have to purchase an alignment bar one day, always assume owning a boat means you have unavoidable costs included in said ownership.

 

[ranger481vs]

Ok, I removed the drive. I'm not exactly sure how to inspect everything. The gimbal bearing was greasy, so not sure how that affects things, but I put a finger inside the bearing casing and could not rotate it with one finger. My finger just slid on the grease. Then, I pinched the outside edge of the casing with two finger and could not rotate it. Once I cleaned off the grease, I could rotate the casing with two fingers. It felt smooth, but it didn't move very freely. If I need to replace this part, is there a recommendation between sealed bearing or greasable?

Also, looking at my u-joint, could use some advice, as I'm not sure how to inspect that either.

In the bottom of the bellows in front of the gimbal bearing, there is some greasy liquid, much like oil. Didn't feel watery, and it was a consistent viscosity. See pic of liquid on my finger. Also, in the 3rd pic, I would like to know what this part is. It rotates, so I want to make sure I have it in the correct position when it comes time for reassembly.

 

[Rick Stephens]

That looks like oil in the bellows. But not a lot and could just be grease thrown off the u-joints. Oil will have a distinct gear lube smell. Grease will not have much of a smell at all. Wipe a little more and smell it.

I would see if there is any catching or loose play in the u-joints. And grease em until clean grease comes out. Wipe the rest out with paper towels.

The shifter link goes vertical. Here's the Manual #14 pages that matter. There are copies of this manual to be found, you want to follow it!

 

[ranger481vs]

So, based on my test of the gimbal bearing, does it sound like it's ok, or needs replacing?

I'm enclosing a pic of the u-joint and a video. I couldn't figure out where to grease goes, but maybe in the center and the zerks must've broke off?

https://youtu.be/JubcLh9rp84

 

[Rick Stephens]

Gimbal sounds fine.

No way to know from here if the ujoints are perfect. They may also be sealed, Mercruiser, like everyone, reduces maintenance by going sealed joints and gimbal bearings. Either can be seen though.Your entire constant velocity joint looks dry as a bone, so either sealed or broken zerks. Hopefully someone who knows more about what the sealed units look like.

You got a vibration when turning, most likely ujoints should be replaced. I prefer greasable ones.

Rick

 

[tpenfield]

As Rick says, the u-joints may feel fine, but actually cause noise while turning, indicating that they are worn.

 

[ranger481vs]

Ok, sounds good. I go ahead and replace the u-joint, and go from there.

 

[ranger481vs]

So, I need to replace both cross joints, rather than the whole assembly, correct? The cross joints are about $100 each. I believe this is the part I need:

http://www.marineengine.com/newparts/part_details.php?pnum=MER805536A+2

 

[Rick Stephens]

Or get automotive ones at quarter the price:
https://forums.iboats.com/forum/eng...outdrives/244162-u-joint-part-number?t=238091


Same manufacturers make both.

 

[ranger481vs]

Oh, that's great. I was able to locate PRECISION (MOOG)# 315G part, so I will pick up a couple of those.

 

[ranger481vs]

Well, getting closer, I think.

I got the two u-joint crosses removed okay. I am using a large C-clamp with sockets to remove the old ones and install the new ones. I have the same problem with both crosses. I get the first 3 ends pressed in just fine, but I cannot get the last end pressed in enough to slide the clip on. I'm using an 8" heavy duty forged c-clamp, that's now warped because of this. I could go rent a u-joint tool if that'll make the difference, but wanted to check in here first.

 

[Rick Stephens]

You're sure a pin didn't drop in a cup? I have done that.

 

[ranger481vs]

yeah, I'm guessing that must be the case. I was just reading about someone who had that problem in an an auto forum. Will check it tomorrow, and then buy another u-joint and use those bearing/cups.

 

[tpenfield]

It sounds like something is quite wrong with the u-joint assembly. Either a pin is falling into the cup, or the cups are too big for the yoke. The c-clamp should assemble the new u-joints with ease.

Here is a link to my web page on replacing u-joints. This may help . . .

http://www.tpenfield.com/Formula330/OutDrive_U-Joints.html

You should probably start over with a new set of u-joints and a new c-clamp.