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'1995 5.0L OMC Cobra - ticking from lower unit as unit is trimmed upwards

C

CapnCav

New member
Pulled boat out of garage yesterday to prep it for the season and while running it on a water jacket discovered there is a clicking noise that occurs as the lower unit is trimmed up. When the lower unit is down, no noises, as it's trimmed up, the further up you go, the louder the clicking noise gets.

Turning right or left has no impact on the noise, only raising and lowering the unit.
Noise not there while in neutral.
Clicking speeds up and slows down with speed.
Noise is loudest when lower unit is trimmed all the way up, noise goes away when unit is trimmed almost all the way down.

I'm guessing the U-Joint is going out - that sound right?

Thanks
 
Welcome aboard !

no it might not be going but it is the u-joint. 1-3 inch up i bet i makes no noise, thats how far you raise in it in the water running.
 
I don't ever recall hearing the noise before, and I've run it on a water jacket a number of times in the past.

It is quiet up until it's raised a few inches, then the higher I raise it the louder the noise becomes.

Can the lower unit be pulled off relatively easily so I can have a look at the U-Joint and determine if it needs replacement or not?
I read another thread where someone was talking about pulling a Cobra lower unit and it was determined he had to pull the entire drive, could not just drop the lower unit off.
 
Guess I'll pull the lower unit this weekend and see what's going on in there.

Another thing with this boat, after last season I noticed the lower unit drops down after a couple days.
I always leave it trimmed all the way up, in a couple days, it will be all the way down.
There are no fluid leaks anywhere that I can see.
It takes a couple days for it to drop all the way down.

Looking in the manual I have it talks about the possibility of check valves in the pump leaking and allowing the unit to slowly drop back down.
Would that be the most common cause for this? What about the actual lift ram on the lower unit, can those leak internally and cause the same problem?
 
Sounds like u-joints to me. BTW, you shouldn't trim the drive up too high with the engine running. Yes, most likely leaking check valve in trim pump.
 
I normally don't trim it up any more than necessary to run it on a water jacket.
This time it may have been a little higher than normal, but not outside the normal range used while launching or retrieving.

I did run it up pretty high to see what was going on once I noticed the clicking, at idle of course, and only long enough to determine that the clicking noise did indeed continue to increase in intensity as the unit continued to be tilted up.

Hope to pull the lower unit this weekend and get a look at what the problem is.

I'll report back what I find once I have it apart.

I really appreciate all the help and tips, you guys are great!
 
Pulled the lower unit off last week, there was a mix of watery grease in the bellows.
Not a lot of water, but enough moisture to cause a problem.
Bellows looked fine, but I had already ordered a new one, so I went ahead and installed it.
The bellows is a tight fit, but you can get the old one off and the new one on without removing anything but the lower unit.

U-Joints just needed a lot of lube, gimbal bearing was light on lube too.

New Bellows in, U-Joints lubes, Gimbal Bearing lubed, put it all back together and it sounds right again.

Still have the issue with the tilt/trim leaking down, takes a little over a day for the unit to drop all the way down from the up position.

Thanks for the the help!
 
I believe you're right, but if nothing else, the noise got me to pull the lower unit and get the u-joints greased.
They were really in need of lube.

In all the years I've run a lower unit on a water jacket, I don't recall ever running the lower unit up much.
I'll remember to not run it up more than a few inches when on a jacket (normally I'd just run it as low as I can get it).

I've never pulled a lower unit off before, now I have, and it really wasn't a big deal, it's just heavy and a little tricky to get everything lined back up to put it back together.

Again, I appreciate the comments and help.
 
I am not blasting you and i may seem curt. but i am just stating my opinion.

I'm glad your learning your drive, keeps more money in your pocket.

Good luck !
 
Woodieman,

Is the check valve in the trim pump replaceable, or does it mean a whole new trim pump? I have similar symptoms (4.3L Cobra, 1993)
 
oh you should not be leaving the drive up all the time anyway.

To extend the life of the billows and in the winters should be stored down.
 
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