Trim and tilt problems on 5.0L

[ggundersen3]

The trim and tilt on this boat works OK. All the way up and all the way down, every time without fail, uninterrupted. However, I notice 2 things. If the boat sits for a long period of time with the drive fully up, it doesn't hold, it very, very slowly works its way down. Also, when taking it up or down, especially going full up, I hear a few "knocks" almost like its hitting something but it's not and it does not interrupt/affect the unit from moving up. Keep in mind its a '95 OMC 5.0L with a replacement Volvo Penta SX Cobra drive.

 

[alldodge]

Most likely the piston seal inside the cylinder is leaking slightly. Replace the internal seal and it will be fine. Don't know about the noise, but check for something binding, U joints need grease (but if they were dry there should be vibrations)

 

[ggundersen3]

Most likely the piston seal inside the cylinder is leaking slightly. Replace the internal seal and it will be fine. Don't know about the noise, but check for something binding, U joints need grease (but if they were dry there should be vibrations)

Thanks! There is a grease fitting on the side of the very top part of the lower unit. What does that grease/lubricate?

 

[Lou C]

Are you referring to the grease fitting on the side of the transom mount? That’s to grease the gimble bearing. The only way to grease the ujoints is to pull the drive which should be done every season for inspection.

 

[alldodge]

Thanks! There is a grease fitting on the side of the very top part of the lower unit. What does that grease/lubricate?

Guess that lubes the gimbal bearing but I'm no VP expert

 

[ggundersen3]

Guess that lubes the gimbal bearing but I'm no VP expert

OK Thanks!

 

[Lou C]

When I do mine I grease it with the engine running on the water hose that spreads it all through the bearing because that bearing turns whenever the engine is running.

 

[ggundersen3]

When I do mine I grease it with the engine running on the water hose that spreads it all through the bearing because that bearing turns whenever the engine is running.

Thanks for the information. A little more background to what's going on. The fact that it won't hold the drive up for a long period of time is not a new problem, it's been that way for a while. However, the "knocking/binding" noise is a relatively new problem and really concerns me. So whats the next step? Have the drive pulled and check the u-joints?

 

[Lou C]

Yep I’d do it before it gets any worse. Should be checked yearly

 

[ggundersen3]

Yep I’d do it before it gets any worse. Should be checked yearly

Just a few questions here before I proceed with diagnosing the knocking/binding noise.
1-What are ALL the symptoms of bad/failing U-Joints? What should I all be watching for?
2-This boat was at the dealer last fall and the drive WAS removed and checked. They replaced the gimble bearing, u-joint bellows and exhaust bellows and set the alignment. Remember this is the boat where I'm trying to determine why I get about one gallon of water(no more, no less) in the bilge after being on the water regardless if its 2 hours or 6 hours. Is there any way these two issues could be related? I've had the boat on the water this season 6-7 times.
3-Regarding the trim and tilt. The pump is located in the far rear on the port side, correct? Can power steering fluid(someone told me that) be used or must it be trim and tilt fluid? If its low on fluid and I add some, does the system have to be bled as there might be air in the lines?
Any other info here appreciated!
Thanks

 

[Scott Danforth]

knocking is often a bad u-joint

pull the drive and look

look at the oil in the system and match. if its brown, its SAE 30 motor oil. if its red, its ATF. the pump is self bleeding. just cycle the trim/tilt its full range about 10 times

 

[dypcdiver]

From your description it sounds to me that you may have 2 issues here.
Firstly, the knocking when trimming could be the cross pins that the trim cylinders mount on binding due to a lack of lubrication, and the gradual lowering is probably the piston seal as mentioned above.
Secondly, the ingress of water is worrying. I would be checking the transom seal, a mobile phone is useful where your head does not fit. Check the hoses that are attached to the power steering oil cooler at the transom. Hopefully when the boat was at the dealers the new bellows were seated and tightened correctly.

 

[ggundersen3]

From your description it sounds to me that you may have 2 issues here.
Firstly, the knocking when trimming could be the cross pins that the trim cylinders mount on binding due to a lack of lubrication, and the gradual lowering is probably the piston seal as mentioned above.
Secondly, the ingress of water is worrying. I would be checking the transom seal, a mobile phone is useful where your head does not fit. Check the hoses that are attached to the power steering oil cooler at the transom. Hopefully when the boat was at the dealers the new bellows were seated and tightened correctly.

dypcdiver explain how the cross pins that the trim cylinders mount to get lubricated. Attached are a couple pics of the drive. Thanks in advance

 

[Lou C]

When I R&R the drive each year I have always greased that Ram rod & the bushings & never had noise from there. I guess if the bushings are worn & have play that could cause noise. You remove at least one of the nuts on the rod then lube the rod in the bushings and use a socket & ratchet to twist the rod out of the rams & the drive pulling it all the way out. I use Evinrude triple guard grease on these & never had em seize up even with all my salt water moorage. But first see if there’s play in the hinge pins up & down & side to side. Mine has nearly none. No noise at all trimming turning etc.
IIRC OMC used dexron ATF in the trim & p/s system. I know for sure when one of my trim lines leaked the fluid was definitely red like ATF. The p/s system I dealt with last year when I changed the p/s actuator which was leaking atf in the bilge for a while.

 

[dypcdiver]

This is the setup you have, The nylon bushes that are located in the trim cylinder ends can get corrosion surrounding them and become tight on the Pivot pins (cross pins). there are also similar bushes in the body of the leg that can suffer the same problem. Clean them up and lubricate them each year when you pull the leg.

Lou C has answered your concerns about the fluids.

 

[ggundersen3]

Here's a pic of the trim and tilt pump. Is the red cap the "fill" cap? Does it twist counterclockwise to open? I couldn't get it to move and didn't want to force/break it. Is it where I'd check the level?

 

[alldodge]

Does it twist counterclockwise to open?

I would say yes, but have not ever removed one