Question 1

When should the bellows of a mechanical shaft seal be replaced?

Accepted Answer

Mechanical face-type shaft seals are highly reliable, but the rubber bellows age and harden over time. Following the manufacturer’s recommendation, the bellows should generally be replaced every 6 years as a precaution, even if no damage is visible. The carbon and stainless steel sealing faces and the bellows clamps should be checked at every haul-out.

Question 2

Why does my boat vibrate under way?

Accepted Answer

The most common causes of vibration under way are an unbalanced or damaged propeller, a bent shaft, a worn shaft bearing, poor engine-to-shaft alignment and worn engine mounts. If ignored, it causes lasting damage to gearbox bearings, seals and engine mounts. The RPM at which the vibration starts is an important clue to its source.

Question 3

Why should shaft alignment be done after the boat is launched?

Accepted Answer

When the boat is ashore it rests on blocks and stands; once launched, the hull is supported differently and flexes slightly. Alignment done ashore can therefore be lost when the boat goes back in the water. The correct procedure is a preliminary alignment ashore and the final alignment after the boat has been launched and the hull has settled.

Question 4

How much should a traditional stuffing box drip?

Accepted Answer

With traditional packing, a small amount of dripping while the shaft is turning is normal and cools the packing; when the shaft is stationary there should be little or no dripping. Overtightening causes heat and shaft wear, while a loose gland lets too much water into the bilge. Correct adjustment and timely repacking prevent both problems.

Question 5

When should the cutlass bearing be replaced?

Accepted Answer

Shaft bearings should be checked at every haul-out. If there is noticeable play when the shaft is moved up and down by hand, if there is vibration or knocking under way, or if the rubber bearing surface is visibly worn, the bearing needs replacing. A worn bearing also quickly wears the shaft and the seal.

Question 6

Can a damaged propeller be repaired, or should it be replaced?

Accepted Answer

Bent blades, edge nicks and moderate impact damage can usually be repaired; with straightening, weld build-up, profile checks and balancing, the propeller can be returned to service. If a blade is broken off, the hub is cracked or there is heavy material loss, a new propeller may be the better choice. After inspection we present both options.

Question 7

Why is propeller balancing important?

Accepted Answer

An unbalanced propeller applies an uneven force to the shaft with every revolution. This causes vibration, noise, wear of the cutlass bearing and shaft seal, and in the long run damage to the gearbox bearings. A repaired propeller should not go back on the boat without being balanced.

Question 8

What is propeller cavitation?

Accepted Answer

Cavitation is the gradual pitting of the blade surface caused by the collapse of vapour bubbles that form when pressure on the blade drops too low. Blade damage, the wrong propeller choice or a distorted blade profile increase cavitation. If sponge-like pitting appears on the blade surface, the propeller should be inspected.

Question 9

My gearbox is slow to engage or slips out of gear. What is the cause?

Accepted Answer

These symptoms are usually caused by low gearbox oil level, low operating pressure, worn clutch plates or a misadjusted shift cable. The control adjustment and oil level are checked first; if the problem persists, the operating pressure is measured to assess the internal condition of the gearbox.

Question 10

Why does gearbox oil look milky?

Accepted Answer

Milky gearbox oil means water has mixed with the oil. The most common cause is an internal leak in the seawater-cooled gearbox oil cooler. The boat should not be used in this condition, as water-contaminated oil quickly destroys bearings and gears. The cooler must be repaired or replaced and the oil system flushed.

Question 11

When should the shaft anode be replaced?

Accepted Answer

The shaft anode should be checked every season and replaced when it is about half worn. The anode protects the shaft and propeller from galvanic corrosion by corroding in their place. If the anode wears much faster than expected, it may indicate stray current or a bonding problem on the boat.

Question 12

Do you work with the boat ashore or afloat?

Accepted Answer

Both. Shaft seal checks, shaft alignment, vibration diagnosis and much of the gearbox service can be done with the boat afloat. Shaft and bearing replacement, propeller removal and some seal replacements require the boat to be hauled out. We provide on-site service in marinas and boatyards across Turkey.

Question 13

What should I do if water is coming in through the shaft?

Accepted Answer

Increased water ingress through the shaft seal or stuffing box requires urgent attention. Make sure the bilge pumps are working, do not leave the boat unattended and contact us immediately. We respond as quickly as possible to locate the leak, make it safe and carry out a permanent repair.

Kontrol Kalemi	Önerilen Sıklık	Not
Şaft keçesi / salmastra	Her sezon ve her karaya alımda	Damlama ve kaçak kontrolü
Mekanik keçe körüğü	Genellikle 6 yılda bir değişim	Üretici önerisine göre
Şaft yatakları	Her karaya alımda	Boşluk ve aşınma kontrolü
Layn (eksen hizası)	Motor/şanzıman müdahalesi sonrası	Son ayar tekne sudayken
Pervane	Her karaya alımda	Hasar, kavitasyon ve oturma kontrolü
Şaft anodu	Her sezon	Yarısı aşındığında değişim
Şanzıman yağı	Üretici aralığı veya yılda bir	Renk ve seviye kontrolü

Şaft, Pervane ve Şanzıman Servisi

Şaft, Pervane, Şanzıman ve Sevk Sistemleri Bakım ve Onarım Hizmetleri

Sevk Sistemi Hizmet Kapsamımız

Şaft Sızdırmazlık Sistemleri: Şaft Keçesi ve Salmastra

Layn Alma: Motor-Şaft Eksen Hizalaması

Şaft ve Şaft Yatakları

Pervane Bakım, Onarım ve Balans

Marin Şanzıman Servisi

Galvanik Korozyon Koruması ve Şaft Topraklama

Sevk Sisteminde Sorun Olduğunu Gösteren 5 İşaret

Periyodik Kontrol Rehberi

Neden EPS Marine?

Sıkça Sorulan Sorular

Türkiye Genelinde Yerinde Sevk Sistemi Servisi