Steering oscillates back and forth, boat/motor shakes.

[Cobalt_262]

I have been dealing with this since the end of last season and have not been able to resolve it. It usually will occur when the trim is anywhere but all the down, but it doesn't do it all the time. It will immediately stop shaking when shifted into fwd/rev. I was thinking that was the power steering acting up, not now I wonder of its possibly a u-joint or something with the gimbal bearing. Please see the video. Any help would be greatly appreciated

Volvo Penta 8.1Gi-b DP-S

 

[muc]

Welcome to Iboats.
If you post a serial number someone might be able to look a little deeper.

I have seen seen this a few times but it was always on SX style transom plates. Your post seems to say you have a DP-S but then you ask about a gimbal bearing. A DP-S doesn’t have a gimbal bearing.

i will tell you what we found on the SX style and maybe it will help.
I mostly work on twin engine boats and they don’t do this. But on Saturday’s I work on what ever comes in and that’s when the first one showed up. I checked hydraulic pressure expecting it to be high but it was good. The power steering rack seemed to be good so I shimmed up the gimbal ring because it had dropped a little and was too loose. That stopped the oscillation‘s. The next boat was still under warranty and the technician working on it contacted Volvo tech support, they had him replace the steering rack and that didn’t fix it. Service writer then remembered that I had this same problem a few months ago and had the tech add some shims. And that’s how we’ve taken care of this problem since then.

If if you do have a DP-S. You might want to take a close look at the suspension fork and see if it has dropped or is loose. I would think that raising the trim might cause the fork to be pushed up and take some of the play out of the system.

 

[Cobalt_262]

Welcome to Iboats.
If you post a serial number someone might be able to look a little deeper.

I have seen seen this a few times but it was always on SX style transom plates. Your post seems to say you have a DP-S but then you ask about a gimbal bearing. A DP-S doesn’t have a gimbal bearing.

i will tell you what we found on the SX style and maybe it will help.
I mostly work on twin engine boats and they don’t do this. But on Saturday’s I work on what ever comes in and that’s when the first one showed up. I checked hydraulic pressure expecting it to be high but it was good. The power steering rack seemed to be good so I shimmed up the gimbal ring because it had dropped a little and was too loose. That stopped the oscillation‘s. The next boat was still under warranty and the technician working on it contacted Volvo tech support, they had him replace the steering rack and that didn’t fix it. Service writer then remembered that I had this same problem a few months ago and had the tech add some shims. And that’s how we’ve taken care of this problem since then.

If if you do have a DP-S. You might want to take a close look at the suspension fork and see if it has dropped or is loose. I would think that raising the trim might cause the fork to be pushed up and take some of the play out of the system.

Engine	4012077764
Transom Shield	4151015972
Drive	4202062531

You are correct, I have an SX-MHP transom sheild Product #3868850. The cover plate on the drive says "DP" so I guess that why I presumed it was a DP-S. So you think the gimbal ring may need to be shimmed? Let me add that this didn't start happening until after I hit a sandbar at low speed at a area that I was unfamiliar with. I immediately checked the prop and lower unit and found no damage. I know these drives are suppose to "kick" themselves up in the event of something like this, but since that event the problem has been occurring.

 

[muc]

Thanks for the serial number, it really helps someone like me. You have a DP-SM drive, funny how much difference one letter can make.

The added info that this started after a bottom strike along with the fact that the steering rack was replaced in 2004 under warranty (coded as cracked) causes me to recommend that this be inspected very closely. Unless you have lost steering at speed and experienced what happens ---- I don't think I can describe well enough how quickly somebody can get injured or killed. You will have to make the decision if you or the shop you pick is capable of inspecting this.

If you decide to do the shimming yourself. It is covered in service manual VPA 7743008 12-2003

 

[Cobalt_262]

So you think it's in the gimbal ring or the steering rack? I have had zero issues other than how it shakes at times and why would going into gear or trimming all the way down make it stop. I'm thinking it's not the steering rack by the way it shakes the motor and transom. I appreciate the assistance. I do have the service manual you mentioned, and will be checking out the procedure.

 

[muc]

I don't know. I'm not there looking at it.

If something is cracked you will have zero issues until it breaks and all heck breaks loose.

Is the rack installed properly? Not to tight not to loose? Wrench flats straight up and down? clevis pins not worn or to tight? Steering cable attached correctly? Remember the rack has been replaced at least once. I have no idea if it was done right.

How is the rest of the system? Steering arm to gimbal ring tight? Gimbal ring has the right amount up and down movement?
You need to check out the complete system.

Don't know why in gear or trim might affect this. The few that I've repaired or instructed a junior tech on, I never tried in gear and by jerking the steering wheel the right way I could cause it to happen even when slightly trimmed.

This job can be done without removing the drive --- if you know where to apply the pressure --- and the washers that you use as shims are less than $2.00 each. I would sure try this first. Because when your guessing at what the cause is always try the cheapest and easiest things first. AFTER checking the ENTIRE steering system.

 

[89retta]

I've had the same problem once or twice a season. And like you when I start up and trim is around half. I just shut the engine off trim down , start back up and off I go

 

[stang32]

has anyone resolvd this issue? i could not find any info on shimming the gimbal ring.

 

[muc]

has anyone resolvd this issue? i could not find any info on shimming the gimbal ring.

page 32

 

[GA_Boater]

has anyone resolvd this issue? i could not find any info on shimming the gimbal ring.

If page 32 doesn't help, start a new thread of your own

Closed.