2003 F90 Tilt Trim Sagging Problem , Help Please

[Kanadakid]

I have one problem that has now turned into 2 problems, please let me explain.

Last fall I noticed that when I trimed my engine while running in would sag, sink to a lower running position. In other words would not stay trimed out but would gradually lower itself.

A friend and I opened the top hex bolt and bled some air out of it and seemed to operate better, holding position. He suggested we change the TT oil in spring.

We tried this a few weeks ago but could not get the lower large slotted plug out. Some of the oil ran out . We put the hex bolt back in and noticed that it was sagging again.

This weekend we put more oil in it, bled the system and it still sagged while running. This moring I went out and raised and lowered the T/T and noticed that it was sagging faster.

I slowly losened the hex bolt and heard air gurggling. Went to tighten it back and noticed the threads were srtippped on the bolt.

So the first thing I need to do is put a healycoil on to match the hex bolt. Not sure I can find an aluminium healycoil. Will putting stainess coil react with the aluminum ? Or is this OK ?

Any ideas on what can be causing my issue. When fully tilted up the engine will stay. When at the mid point it will start to sag.

1) Can / should I replace the ram seals ?
2) Do you think I just have air in the system.

The engine is used in fresh water only and garage kept. So there is no rust or corrosion of any kind.

Thanks in advance, would like to get this resolved wothout spending $500. in parts for an engine that is only in use for 4 years.


Kid

[boats.net]

SS heli-coil is ok but you need to remove reservoir from power trim unit before drilling, if you get metal shavings inside it can affect valves inside unit. Bleeding air is the first thing to try.

[Kanadakid]

Thanks for the feedback. I should not have to drill. The tap will fit into the hole w/o drilling. I was going to put grease on the tap and slowly tap out the hole, cleaning and replacing the grease 10-12 times, then flush the resevoir 2 or 3 times.

Any thoughts on why this was sinking ?

Thanks

Kid

[mitch]

Have you checked the emergency bleed screw to see if it is tight

Also there is a better type of re-threading that is available in USA than heli coils but I can not remember what they are called i will have to check and see if i can find them.

found http://www.timesert.com/

[Kanadakid]

Mitch, I looked at what you sent me and picked up the Time -Sert for this application. The one key feature I like is that the oil seal will seat much better than with Heli-coil. Thanks for the info, this was a good find.


I am concerend about drilling and getting shavings into the oil reseviour.

Does anyone know if there is a screen below the fill hole ?

Does this tilt trim have an oil drain plug ?

Any tricks other than grease on the drill bit and tap to prevent filings from falling into the engine / oil reseviour ?

Kid

[mitch]

There are 2 filters listed in the parts but they are only small have a look at this parts break down .

Good strong suction with a vacuum cleaner I am sure you could rig something up piece of 12 mm hose bent with drill in the side .

was the emergency screw tight ?

link

http://www.boats.net/parts/search/Ya...201/parts.html

[jmw1818]

SS heli-coil is ok but you need to remove reservoir from power trim unit before drilling, if you get metal shavings inside it can affect valves inside unit. Bleeding air is the first thing to try.

I believe I lost some shavings in my unit but by a totally different process. The tilt will drift down slowly when all the way up. Not sure if it was the chicken or the egg that came first. Is it possible to clean the valves out or do i have to replace them if they had an encounter with the metal shavings.