1993 sanger direct drive vibration

[mightyhye]

I have a 1993 ski sanger dxII with a mercruiser competition ski motor, direct drive. Boat only has 250 hrs on it and motor runs awesome. Just winterized it for storage and while doing so, at above 1500 rpm's the drive vibrates very bad around the transmission/shaft area.

It's not the motor because it doesn't vibrate without the prop engaged at any rpm, just when the boat is actually in gear and prop is spinning.

I was winterizing the boat out of the water on my trailer (with hose and fake-a-lake attachment) and was wondering if this could be the cause of the vibrations as I heard that some cutlass bearings or other type of bearings need water to lubricate themselves.

Aside from possible shaft being bent (which I doubt - cause prop is not nicked and turns true at low rpm's), what types of bearings or tranny issues should I be checking for or looking to replace as routine maintenance?

thxs

-shawn

 

[Don S]

Re: 1993 sanger direct drive vibration

Engine alignment would be the first place I would check. Any movement between the shaft and the cutlass bearing?

 

[JUSTINTIME]

Re: 1993 sanger direct drive vibration

have u hit anything?
try an aliment first, but it sounds like a shaft and strut problem

 

[salty87]

Re: 1993 sanger direct drive vibration

...at above 1500 rpm's the drive vibrates very bad around the transmission/shaft area.

It's not the motor because it doesn't vibrate without the prop engaged at any rpm, just when the boat is actually in gear and prop is spinning.

I was winterizing the boat out of the water on my trailer (with hose and fake-a-lake attachment) and was wondering if this could be the cause of the vibrations as I heard that some cutlass bearings or other type of bearings need water to lubricate themselves....

i'm a little confused, happens alot. was the boat in gear on the trailer?

if so, spinning the prop without wetting the cutlass bearings is bad. they're rubber bushings inside the strut, which is the support for the shaft. they work great when wet. burn up when run dry.

you should inspect them if they've been run dry. they should wear evenly around the edges on the leading and trailing edge of the strut. they do wear from use and time as the rubber ages.

if you haven't hit anything and the vibration is new that's likely it. checking alignment is routine maint though. change transmission fluid.

 

[mightyhye]

Re: 1993 sanger direct drive vibration

thanks for the replies...

to answer some questions-

1. haven't hit anything, and prop looks good
2. ran for a couple minutes on trailer to warm up motor for an oil change when I heard the vibration start to happen. I ran the motor for about 10 minutes in all but the vibration started the second I put the prop in gear and revved up rpm's up a little
3. no significant movement between shaft and cutlass bearing

tranny fluid looks good and I was planning on changing it at the start of next season anyways. doesn't smell burnt and I don't think its the tranny thats causing the vibration. I'm just trying to troubleshoot and rule out any of the so-called cheaper culprits before I try to diagnose if its gears in the tranny.

I guess I'll also do a search on "how to check engine alignment" before I proceed. Is it common for these inboard mercs to get out of alignment? what can cause that (just normal after time)?

thxs,

-shawn

 

[jerryjerry05]

Re: 1993 sanger direct drive vibration

If you ran the motor in gear out of the water the cutlass bearing will need to be replaced.It only takes seconds to ruin one.Just setting at idle not in the water the prop will still turn and heat up the bearing.
In the case of alignment smaller boats don't go out as often as a bigger boat.Bigger boat when hauled and blocked for any length of time need to be checked.When you check alignment the boat should be in the water and set for a few hours. But it sounds like you cooked the bearing.
The good news is that when you replace the bearing you will need to re-align the shaft anyway!!!!!!!!!Jerry

 

[salty87]

Re: 1993 sanger direct drive vibration

Just setting at idle not in the water the prop will still turn and heat up the bearing.

prop shouldn't turn at all in idle. i'm sure there's a mercruiser procedure for alignment, you should probably use it but i'm sure it's pretty close to this info: http://supraboats.com/bbs/showthread.php?t=2322

your motor mounts probably adjust differently but the idea will be the same.

changing the bearings requires pulling the shaft and that's not always as easy to do as it is to say. all this stuff should be checked periodically but it's not fun. things are often seized together pretty good with little working room. you can check the alignment more easily.

i'd visually inspect the bearings and go from there. chances are they're worn down pretty good but you never know without looking. if they look good, see how it goes when you get it back in the water...unless you're eager to take it apart. if the bearings are worn, you'll get the chance to inspect the rest alot better. it's a good idea to check the alignment anyway though. i doubt there's anything wrong with the tranmission...again, unless you hit something or ran the fluid dry.

 

[mightyhye]

Re: 1993 sanger direct drive vibration

thanks guys...think I'm just gonna check the alignment and change any necessary bearings. this boat is 15 years old and I doubt the previous owner checked or changed any bearings during his ownership.

Hate to be having this problem in the water out in the middle of the lake unexpectedly!