The members of this forum seem to happily share their wealth of knowledge. I have damaged my drive train and could use some help diagnosing the problem.
My boat is a Seaswirl Striper 210 that I purchased new in 1994. It is powered by an OMC Cobra 5.0 Fl with an SX outdrive. Since there are far more of the identical Volvo Penta SX power trains on the water I figured I would be better off posting to the VP forum.
I have launched my boat the same way without incident many times in the 23 years that I have owned it but yesterday I misjudged low tide conditions at a fairly flat ramp and damaged my prop as I backed off of the trailer. The engine stalled but the skeg was not damaged.
I purchased a new prop at a nearby marine store, installed it and launched successfully. Unfortunately, I quickly realized that something else in my drive train has been damaged. There is a pronounced vibration that I can feel throughout the boat. While on the water, I never attempted to accelerate beyond headway speed. The vibration is noticeable at idle and it gets much worse as RPMs increase. The vibration is similar in neutral and in gear so I assume that problem lies somewhere between the engine coupler and the cone clutch but I am only generally familiar with the inner workings of the drive.
In my attempts to troubleshoot I have found the following.
With the drive installed:
· While running, the drive shifts smoothly from neutral to forward or reverse
· Within the limits of visual inspection the prop shaft appears to be undamaged and running true.
· I used a mechanic’s stethoscope to probe various points on the drive with the engine running in neutral and in gear. I’m certainly not an expert but I didn’t identify any obvious noises that seemed to indicate gear mesh or bearing issues.
· Neither trimming up nor steering from lock to lock seems to significantly change the vibration.
With the drive removed:
· Both U-joints feel normal with no obvious play or binding.
· The gimbal bearing feels normal with no obvious play or binding.
· There is no obvious play where the input shaft enters the upper gear housing.
· While turning the input shaft by hand, there is no obvious binding or free play in neutral, forward or reverse.
· My engine alignment tool slides in and out of the coupler with little resistance (only checked in one position, did not rotate crank shaft).
· With a friend holding a hose to the cooling inlet I briefly ran the engine with the drive removed. I was pretty cautious with the throttle while running this way but it seemed that the vibration was gone or at least less obvious.
I would have expected that anything that could cause the boat to vibrate so badly would be fairly obvious. Since I haven’t identified any unusual binding free play or metallic noises I am inclined to suspect the engine coupler but I admit that that is a bit of a stab in the dark.
Perhaps this will become an insurance claim and a professional mechanics problem but I can’t afford to foot that bill on my own and I enjoy doing my own work when I can. Any advice would be greatly appreciated.
My boat is a Seaswirl Striper 210 that I purchased new in 1994. It is powered by an OMC Cobra 5.0 Fl with an SX outdrive. Since there are far more of the identical Volvo Penta SX power trains on the water I figured I would be better off posting to the VP forum.
I have launched my boat the same way without incident many times in the 23 years that I have owned it but yesterday I misjudged low tide conditions at a fairly flat ramp and damaged my prop as I backed off of the trailer. The engine stalled but the skeg was not damaged.
I purchased a new prop at a nearby marine store, installed it and launched successfully. Unfortunately, I quickly realized that something else in my drive train has been damaged. There is a pronounced vibration that I can feel throughout the boat. While on the water, I never attempted to accelerate beyond headway speed. The vibration is noticeable at idle and it gets much worse as RPMs increase. The vibration is similar in neutral and in gear so I assume that problem lies somewhere between the engine coupler and the cone clutch but I am only generally familiar with the inner workings of the drive.
In my attempts to troubleshoot I have found the following.
With the drive installed:
· While running, the drive shifts smoothly from neutral to forward or reverse
· Within the limits of visual inspection the prop shaft appears to be undamaged and running true.
· I used a mechanic’s stethoscope to probe various points on the drive with the engine running in neutral and in gear. I’m certainly not an expert but I didn’t identify any obvious noises that seemed to indicate gear mesh or bearing issues.
· Neither trimming up nor steering from lock to lock seems to significantly change the vibration.
With the drive removed:
· Both U-joints feel normal with no obvious play or binding.
· The gimbal bearing feels normal with no obvious play or binding.
· There is no obvious play where the input shaft enters the upper gear housing.
· While turning the input shaft by hand, there is no obvious binding or free play in neutral, forward or reverse.
· My engine alignment tool slides in and out of the coupler with little resistance (only checked in one position, did not rotate crank shaft).
· With a friend holding a hose to the cooling inlet I briefly ran the engine with the drive removed. I was pretty cautious with the throttle while running this way but it seemed that the vibration was gone or at least less obvious.
I would have expected that anything that could cause the boat to vibrate so badly would be fairly obvious. Since I haven’t identified any unusual binding free play or metallic noises I am inclined to suspect the engine coupler but I admit that that is a bit of a stab in the dark.
Perhaps this will become an insurance claim and a professional mechanics problem but I can’t afford to foot that bill on my own and I enjoy doing my own work when I can. Any advice would be greatly appreciated.