1988 Merc 5.7L 350mag - Powering steering shaking the boat on moderate turns @ dock.

Fastrack

Petty Officer 3rd Class
Joined
Aug 8, 2011
Messages
95
Hey.

I bought this boat last year, the pump was low on fluid. I dono if there was a leak, but I did find the hose to the PS cooler loose (Port motor mount had oil on it, so I suspect it was leaking from this connection. So I tightened that up. It's no longer loosing fluid.

The powering steering is EASY, 1 finger to turn the wheel so I doubt there's any binding.

What has been done since I got the boat July 2016:
- New Coupler
- Gimbal Bearing
- New U-joints on the old Upper last fall - but since found the bearings were pitted SE106 upper was ordered this year.
- New SE106 upper/lower (Old lower had a wobbly prop shaft, and the upper bearings were quite pitted.. cheaper to go aftermarket)

- Tilt angle doesn't change this shake
- Shake stops when wheel is not being turned
- Alignment is spot on even after sitting over the winter - two fingers in/out. Spline mesh looks the same around the alignment bar
- Brand new accessory belts installed yesterday - belts were glazed anyway and quite stiff
- PS pump pulley rotates smoothly, no bearing issues
- Removing the PS belt it goes away. But of course it's harder to dock the boat without PS :)

I've followed the merc bleeding procedure a few days now.. to a T a with the engine OFF. I saw small bubbles in the reservoir but nothing major. I just repeated it 30 TIMES after sitting overnight. I even let it rest a few minutes between each batch of 10.

Could it need more bleeding??

Could something be wrong with the relief valve or the pump itself? Ram??

Can I remove the ram from the steering arm, to rule out the drive completely?? Or will weird stuff happen when it's not connected to anything?

Thanks in advance,

Ben
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,598
Check to see if the slot on the tube is vertical (d) and nut (c) is tight

Steering Ram.jpg
 

Fastrack

Petty Officer 3rd Class
Joined
Aug 8, 2011
Messages
95
Check to see if the slot on the tube is vertical (d) and nut (c) is tight


I think the one on mine is the original 1988. It doesn't have that slot. Mine looks like the one found in this post:
http://forums.iboats.com/forum/engin...54#post4492854 steeringBoat.jpg

Well mine isn't all rusty like that. There is a LOT of slope in the connection that's circled in RED.

The bleeding I did repeat 30 times, seemed to reduce the shake slightly. I'm gonna try it again tomorrow morning.

I have greased the shaft that extends out as well. It's smooth with no rust. The nut from the cable is also tight.

Ben
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,598
Not an expert, but if it was me I would look at replacing the ram with the newer style
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
If all the air is gone and it's still shaking, I'd bet you've got a worn ram or shuttle valve. Replace or rebuild.

Chris...........
 
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