More on the Gimbal Bearing/U joint noise

[CharlesW]

Just a quick summary.<br />1993 OMC Cobra with a 5.0 Ford. Purchased new and pretty well maintained.<br />I have a slight rumble when I turn all the way right/left at anything above an idle speed. Not bad, but I'm sure it hasn't been there in the past.<br /><br />Today, I removed the outdrive. The gimbal bearing turned freely and felt silky smooth. Appeared to be well lubed so my grease must be getting to the bearing. So, the noise is probably not the gimbal bearing, right?<br />There doesn't seem to be any wear or slop in the U joints, either. Everything looks well lubed and in good shape.<br />With the outdrive off, I turned the splined driveshaft and U joints by hand. Turned easily and smoothly, but there was a slight squeaking noise from the outdrive itself. It was almost like a dry seal type of sound. I had just drained and refilled the gear oil prior to removing the outdrive so I know it has lubricant in it. Is a faint squeak a normal sound from the outdrive when turning the input shaft? Seems unlikely, but I have never had the occasion to check it previously.<br />Anyway, it will go the shop this week for their inspection and opinion.<br />Thanks for all the help, opinions. and advice. I'll post the shop findings after they check it.

 

[AIRNAUTIQUE4EVER]

Re: More on the Gimbal Bearing/U joint noise

The squeak is probably your impeller turning, if i remember right it is under the cover on the outdrive towards the back on the top housing. the slight rumble could be your power steering pump check your fluid and belt tension.

 

[marinemech]

Re: More on the Gimbal Bearing/U joint noise

the squeak is probably the water pump impeller<br />does the noise go away with a small amount of trim?

 

[Bondo]

Re: More on the Gimbal Bearing/U joint noise

I Don't do OMCs,<br />But wouldn't that be the Impeller Squeaking ??????

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

Originally posted by AIRNAUTIQUE4EVER:<br /> The squeak is probably your impeller turning, if i remember right it is under the cover on the outdrive towards the back on the top housing. the slight rumble could be your power steering pump check your fluid and belt tension.

The impeller makes sense. That's about where the noise seems to be coming from. The PS fluid and belts were checked in the spring, but I didn't check the fluid when the sound started. <br />If the outdrive checks out O.K., the PS fluid will be my first thing to check when the boat comes out of storage in the spring.<br />Thanks.

 

[Bt Doctur]

Re: More on the Gimbal Bearing/U joint noise

Replacing the U joints would be a good idea because if it lets go theres going to be an awful lot of damage done.

 

[Bondo]

Re: More on the Gimbal Bearing/U joint noise

3 Replies in 5 minutes.............<br /><br />We're getting Better......................

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

Originally posted by marinemech:<br />does the noise go away with a small amount of trim?

I tried various degrees of trim and really couldn't tell any difference. FWI, probably 95% of our running is with neutral trim.<br />Another related (?) item. The trim fluid is down about 3/8" when I checked it today. would slightly low trim fluid let the trim cylinders vibrate and cause a rumbling sound?

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

The comment about repacing the U joints before they cause severe damage was noted.<br /><br />The comment about 3 replies in 5 minutes was noted as well.<br /><br />Hey, you guys are so good, I'm not sure I can stand it if you get any better.

 

[marinemech]

Re: More on the Gimbal Bearing/U joint noise

low trim oil probably not an issue replace "u" joints as above also check engine alignment need a special tool when alignment is good turn engine 180 degrees and check again coupler could be out of round

 

[marinemech]

Re: More on the Gimbal Bearing/U joint noise

when you refilled the gear oil you filled it from the middle screw right if not drain oil from middle screw and refill oil

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

Originally posted by marinemech:<br /> when you refilled the gear oil you filled it from the middle screw right

Sure did.

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

If the problem is the U joints, I have no problem with replacing them. The problem I have is how to determine the condition of the U joints. They don't seem to have any play or slop in them. They look O.K. and they are well lubed, so what do I look for as an indication that they are indeed bad? Possibly a rumbling noise when turning. My original thread on this problem was concerning U joints, but the gimbal bearing issue was brought up and I fully expected to find a rough turning gimbal bearing when I removed the outdrive. Not the case, though.<br />So, should I just go ahead and replace the U joints and see if the noise is gone next season?<br />The boat has given me 12 good seasons, so I don't feel bad spending some money on it if it will fix the problem. By the same token, I don't want to just start throwing parts at the problem and hope one of them fixes it.

 

[Don S]

Re: More on the Gimbal Bearing/U joint noise

I've seen many u-joints that looked good and felt good, but when taken apart the cross piece had grooves in the bearing surface that caused the rumble. And if you take them apart to look, don't even think about trying to put them back together. No way will you ever get the needles back in the original spots and the caps in the correct place.

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

A couple of important questions I forgot to ask.<br />Is replacing the U joints a DIY job?<br />Does it require any special tools?

 

[tylerin]

Re: More on the Gimbal Bearing/U joint noise

So, should I just go ahead and replace the U joints and see if the noise is gone next season?<br />

Replace u-joints, gimbal, align and put her back together you'll be good to go.

 

[tylerin]

Re: More on the Gimbal Bearing/U joint noise

Is replacing the U joints a DIY job?

Well if you haven't done it before you might want someone else to do it for you.When removing ujoints w/ bearing carrier pay close attention to the shims to not disturb them. You'll need a puller to remove gimbal and alignment tool to align to motor

 

[qystan]

Re: More on the Gimbal Bearing/U joint noise

Grab the coupling shaft and give it a twist to load up the joints. Draw a circle with the u-joint end. If there are wear grooves, you'll feel the notching. Do this before you grease up the unit.<br /><br />Did that on my drive (alpha). Without twisting, nothing could be felt. With the twist the notching is very evident.<br /><br />Don S<br />If my understanding that the OMC u-joint is the same as the Merc is correct. The u-joint can be reassembled if you take it apart. Clean out the regular grease and use a thick grease to stick them into place. In fact, you have to remove 2 caps to install it onto the shaft sockets.<br /><br />Charles<br />If the installation is similar (I am not familiar with OMC) to the Merc (I understand the parts are actually the same). <br /><br />You need 2 sockets and a G-clamp. <br /><br />Use a screwdrive to tap out the retaining C-rings.<br /><br />Socket 1: Internal diameter large enough to receive the u-joint cap into it. A 1 1/16 or 27mm socket works (Merc prop nut socket size). Use this to receive the u-joint as it is pushed out with the G-clamp.<br /><br />Socket 2: Outside diameter smaller than the u-joint cap. Used as a spacer to push the u-joint out from the opposite end using the G-clamp. <br /><br />Take care not to introduce dirt or lose any needles. My mech lost a few from the new joint and the damn thing disintegrated.<br /><br />Good luck.

 

[Don S]

Re: More on the Gimbal Bearing/U joint noise

Maybe I should have said it differently. You shouldn't take them apart and put them back together an expect to get every thing back in place due to wear pattern. You Can however take them apart and put them back together, or you could do it right the first time.

 

[CharlesW]

Re: More on the Gimbal Bearing/U joint noise

The outdrive is at the shop. The mechanic didn't think I had any major problems and might not even really need the new U joints. The problem, according to him, is that the U joints would need to be taken apart to see if they show any chatter marks. Even then, he says they don't always show any damage. On the OMC, taking the old U joints apart, checking them for wear, and putting everything back together would probably cost very nearly as much as just installing new U joints. He says on the OMC, (not a Merc), he would do it in 30 minutes to an hour total labor if he installs new U joints. He's guessing that just checking them would add enough labor cost to pay for one U joint so he suggests either run it like it is, or replace the U joints.<br />I asked him to install new U joints.<br />Now I guess I will have to wait till next year to see if that was my rumble problem.<br />The squeak was the impeller.<br />Thanks for all the help and suggestions.