Shaft/Engine Alignment

[Triskele]

I have a 1981 43" Hatteras DCMY. My mechanic is telling me my shaft and engine are laterally (left to right) out of alignment and that the engine needs to be moved 1/16 to 1/8". To do this, engine will have to be jacked up. Motor mounts removed and slotted. Mechanic claims it is a 20 hour job per engine. Both engines need the work done. Probably looking at $2500. Does this sound right? Reasonable? Spoke with Hatteras tech support and they said that it would not be unrealistic for the shaft and engine on a boat this age to be out of alignment laterally. Does anyone know of someone on the Tennessee River (Chattanooga) that does this kind of work? My guy is good, but would like a second opinion and estimate before going forward.

 

[Canuck Dennis]

How did it happen ? was there running gear damage, grounding, have you checked the running gear first ? 20 hrs per side seems really excessive

 

[Finalee]

I thought the engine mounts had eonough movement built into them to allow loosening , adjusting, and retightening? 1/16 to an 1/8 is very little.

 

[Triskele]

How did it happen ? was there running gear damage, grounding, have you checked the running gear first ? 20 hrs per side seems really excessive

It was kind of this way when I bought the boat. Some vibration and whirring sound from starboard shaft. Something that should have been picked up on the survey, but that's another story. The answer I get on how did it happen is time...that basically, the engine settles and shifts due to time and "twisting" the hull during haul outs over the years. Maybe a bad haul out. I did come out of the channel once and bumped the ground, but am told that probably wasn't enough to cause an engine to be out of alignment. Certainly could have bent the shaft or knocked the strut out of alignment, but am told not likely there as well. Shaft is not bent when removed from engine couple.

 

[Triskele]

I thought the engine mounts had eonough movement built into them to allow loosening , adjusting, and retightening? 1/16 to an 1/8 is very little.

I tend to agree with you. Seems like the mount holes have at least a 1/16 to 1/8" play, but mechanic says not enough cause the direction it needs to be moved there is no play. I'm thinking the misalignment is more than 1/8". Maybe more like 3/32 or 1/4.

 

[Angela]

If it seems excessive, have you thought about getting a second opinion/estimate? While I know virtually zilch about how to go about that job, I can tell you for the sake of comparison that I had mine done last year and the charge was about $350 as I recall. He had to move one engine laterally, just a tad. The whole process took him and his son about an hour and a half.

 

[bobk]

Diesel Don is in your area and is very good. His hourly rate is a bit high, but I always found him competent and honest.

Bobk

 

[hattitude]

I tend to agree with you. Seems like the mount holes have at least a 1/16 to 1/8" play, but mechanic says not enough cause the direction it needs to be moved there is no play. I'm thinking the misalignment is more than 1/8". Maybe more like 3/32 or 1/4.

I was chasing a vibration issue several years ago on my 46C. The engines have robust, solid mounts that are shimmed between the mount and the engine bed. Mine had no adjustments on the mounts themselves...

 

[dsharp]

If the boat has an intermediate strut you need to have the boat hauled out and see how the shaft is running through the two struts and how the shaft is running through the stuffing box. What engines are you running? Moving the back of the engines 1/4" is a bunch when talking alignment. Moving the struts may be the way to go after you look at how the shaft is wearing the cutlass bearing. As far as time for the job it depends on how rusty everything is and what has to be removed to get over the engine to lift it. If the stuffing box has been leaking it tends to sling salt water all over the coupling and rear mounts. Is the coupling unbolted from the reduction gear now?

 

[Triskele]

Diesel Don is in your area and is very good. His hourly rate is a bit high, but I always found him competent and honest.

Bobk

thanks!

 

[Triskele]

If it seems excessive, have you thought about getting a second opinion/estimate? While I know virtually zilch about how to go about that job, I can tell you for the sake of comparison that I had mine done last year and the charge was about $350 as I recall. He had to move one engine laterally, just a tad. The whole process took him and his son about an hour and a half.

thank you. Am seeking a second opinion and estimate.