Hi, I own a Catalina 36 with a Universal 25 and Hurth transmission when it is under power there is quite a bit of noise and vibration coming from behind the transmission - maybe closer to the prop. The vibration seems to be rythmic, louder then softer, then louder etc... It seems to have a bit less vibration when running faster around 2200 rpms. Does anyone know what might be the cause of this? Thanks, Mark
Prop, shaft or transmission vibration?
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R
Rick
Engine alignment?
Have you checked to see if the engine and driveshaft are aligned properly? Our C-310 has experienced a rotating knocking noise and the alignment was on the list to check. Finally, I removed the bolts between the driveshaft and transmission flanges. The engine was angled improperly wit a .028" gap near the top of the flanges - a big gap! The manual and experts state that proper alignment will allow tolerance of .003" all around. It has been a tedious process. This weekend, I ran out of time, but I almost have the alignment within .003" tolernance.
Have you checked to see if the engine and driveshaft are aligned properly? Our C-310 has experienced a rotating knocking noise and the alignment was on the list to check. Finally, I removed the bolts between the driveshaft and transmission flanges. The engine was angled improperly wit a .028" gap near the top of the flanges - a big gap! The manual and experts state that proper alignment will allow tolerance of .003" all around. It has been a tedious process. This weekend, I ran out of time, but I almost have the alignment within .003" tolernance.
J
john dewey
ENGINE ALIGN
I AM IN PROCESS OF HAVING A NEW CUTLASS BEARING INSTALLED ON MY 2004 CAT 310. NEVER HAD THE ALIGNMENT PERFORMED. IS IT WORTH HAVING THE YARD DO THE ALIGNMENT? HOW DO YOU JOCKEY THE ENGINE AROUND TO GET THE CLEARANCES? J.D.
I AM IN PROCESS OF HAVING A NEW CUTLASS BEARING INSTALLED ON MY 2004 CAT 310. NEVER HAD THE ALIGNMENT PERFORMED. IS IT WORTH HAVING THE YARD DO THE ALIGNMENT? HOW DO YOU JOCKEY THE ENGINE AROUND TO GET THE CLEARANCES? J.D.
K
Ken
Couldn't link to it, so I've copied instructions
for engine alignment from the Catalina Manual for the 270 for those who want to know the procedure. It is recommended yearly at the least by Cat., and must be done in the water fully rigged. anyone not interested ignore rest of this. SHAFT ALIGNMENT: For proper operation of the engine, the propeller shaft and engine must be aligned. Alignment is gauged at the engine and shaft coupling. Alignment procedures must be done with the boat in the water after the mast is stepped and the rig is tuned. 1. Remove coupling flange bolts and check propeller shaft for clearance. Adjust stuffing box so that excessive seepage is prevented, yet the shaft is allowed to spin freely. 2. Slide shaft away from engine and check coupling mating surfaces. These must be clean. 3. Slide shaft forward to connect coupling surfaces. Pilot on transmission flange must align with recess in shaft coupling flange. This is an indication of correct axial alignment. 4. With coupling flanges in contact, measure gap around edge of coupling flanges with .003 feeler gauge. Maximum allowable gap at any point is three thousandths of an inch. Take this measurement several times ... rotating shaft 1/4 turn each time. Any gap in excess of .003 must be corrected by changing engine position, especially fore/aft tilt. For example, excessive gap at the bottom of the coupling (see drawing) indicates engine is tilted too far aft (front too high). Using a 15/16 end wrench, loosen lock nuts on forward motor mount(s)@ Lower front of engine by clockwise rotation of motor mount nuts. Re-measure gap at coupling. A gap at the top of the coupling would require the-exact reverse procedure. 5. Pull shaft aft as in step 3. Again slide shaft forward, rechecking axial alignment as in step 4. 6. Repeat steps 5 and 6 until alignment within tolerance is achieved. 7. Tighten motor mount lock nuts and install coupling. NOTE: Alignment should be checked yearly, or whenever any excess vibration is noticed. The alignment can also be affected by changes in rigging tension.
for engine alignment from the Catalina Manual for the 270 for those who want to know the procedure. It is recommended yearly at the least by Cat., and must be done in the water fully rigged. anyone not interested ignore rest of this. SHAFT ALIGNMENT: For proper operation of the engine, the propeller shaft and engine must be aligned. Alignment is gauged at the engine and shaft coupling. Alignment procedures must be done with the boat in the water after the mast is stepped and the rig is tuned. 1. Remove coupling flange bolts and check propeller shaft for clearance. Adjust stuffing box so that excessive seepage is prevented, yet the shaft is allowed to spin freely. 2. Slide shaft away from engine and check coupling mating surfaces. These must be clean. 3. Slide shaft forward to connect coupling surfaces. Pilot on transmission flange must align with recess in shaft coupling flange. This is an indication of correct axial alignment. 4. With coupling flanges in contact, measure gap around edge of coupling flanges with .003 feeler gauge. Maximum allowable gap at any point is three thousandths of an inch. Take this measurement several times ... rotating shaft 1/4 turn each time. Any gap in excess of .003 must be corrected by changing engine position, especially fore/aft tilt. For example, excessive gap at the bottom of the coupling (see drawing) indicates engine is tilted too far aft (front too high). Using a 15/16 end wrench, loosen lock nuts on forward motor mount(s)@ Lower front of engine by clockwise rotation of motor mount nuts. Re-measure gap at coupling. A gap at the top of the coupling would require the-exact reverse procedure. 5. Pull shaft aft as in step 3. Again slide shaft forward, rechecking axial alignment as in step 4. 6. Repeat steps 5 and 6 until alignment within tolerance is achieved. 7. Tighten motor mount lock nuts and install coupling. NOTE: Alignment should be checked yearly, or whenever any excess vibration is noticed. The alignment can also be affected by changes in rigging tension.
K
Ken
Shaft Aliignment
Great Write up Ted, I would add that the boat should be floating for at least 24 hours after coming off the hard to ensure the hull is in equilibrium before doing the alignment.
Great Write up Ted, I would add that the boat should be floating for at least 24 hours after coming off the hard to ensure the hull is in equilibrium before doing the alignment.
No credit deserved here, that's straight from
a Catalina Manual & I just "copied & pasted". Generally not too hard to at least check the alignment and as pointed out it can be affected by rigging changes, load changes, etc.
a Catalina Manual & I just "copied & pasted". Generally not too hard to at least check the alignment and as pointed out it can be affected by rigging changes, load changes, etc.
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