Replacing Princess stern glands

[NigelChattin]

Hi,

The stern glands in my Princess 415 leak excessively when we're underway. I've replaced the packing (several times) and the leaks some times improve for a while but before long I'm adjusting the glands again after every trip and emptying gallons of water from the bilge.

So the time has come to do something about it, and repacking again and hoping for the best doesn't seem like the right plan....

Can anyone advise which would be the best option to replace the existing glands? Should I worry about the reliability of new designs? Does anyone have any experience of fitting a modern gland to the existing stern tubes in a 1970s/ 1980s Princess?

I hope you can help - does anyone have any idea what Princess fit to their new boats today?

 

[Bandit]

I have tides marine seals in my boat which I am very pleased with.

Providing you have good access it should not pose a problem.

I had traditional packing in the old boat which needs to drip so always a damp engine room and Deep Sea Seals on this boat which I would never have again.

It may be worth seeing how true your shafts are running and possibly doing cutless bearings at the same time then re aligning the engines.

See http://www.tidesmarine.com/

 

[Tranona]

Tides Marine are the best aftermarket seals for your type of boat. Original equipment now on Fairlines.

 

[PCUK]

I'm not being sarky' but have you done the repacking properly in the past? Used the correct sized packing for a start? Stern glands should not leak excessively even then the shafts are badly worn. Do have a lot of shaft vibration? As previously mentioned a complete check of the shaft bearings and engine alignment will be a good idea before just replacing the glands otherwise you may find the same problems even with modern shaft seals.

 

[Rocksteadee]

I have tides marine seals in my boat which I am very pleased with.

Providing you have good access it should not pose a problem.

I had traditional packing in the old boat which needs to drip so always a damp engine room and Deep Sea Seals on this boat which I would never have again.

It may be worth seeing how true your shafts are running and possibly doing cutless bearings at the same time then re aligning the engines.

See http://www.tidesmarine.com/

I currently have Deap Sea seals fitted which the survey has picked up as requiring replacement......not knowing about these things, is there a problem with them?

 

[Tranona]

I currently have Deap Sea seals fitted which the survey has picked up as requiring replacement......not knowing about these things, is there a problem with them?

They rely on pressure from the bellows to keep the two faces in contact. Surveyor probably knows their reputation and sensible to follow his advice. Seals that use lip seals around the shaft are perhaps the best replacements. Volvo if you have lowish horsepower engines or Tides Marine which are available in larger sizes as well as small.

 

[Bandit]

Deep Sea seals

The manufacturer say that Deep Seals have a 5 year life.

They rely on being compressed and spring in the rubber to hold the two parts tight together.

Mine when i bought the boat we passed by surveyor but at 6 yrs old perished and had no spring in them.

I have seen problems on an identical boat possibly due to instalation problems where they failed.

I am not a fan of the design and changed to Tides marine which i am much happier with from a design point of view.

Withe deep sea if you tighten up the emergency clip on them you also need to stop that shaft from windmilling.

 

[PCUK]

My Deep Sea Seal failed while under way and flooded the engine comp'. Ws able to temporarily fix by compressing the seal very hard against the face.

 

[NigelChattin]

Thank you all for the help

I'm happy I have repacked the stern glands correctly but I'm less convinced the engines are perfectly aligned; the problem is I need the boat out of the water to drop the shaft back slightly and check the engine is aligned with the shaft. I'll not know if that cures it until I'm back in the water and I couldn't face another season with my head in the bilges

I'll have a look at Tide Marine - are there any dangers with them I should worry about? the only thing I do like about the old glands is they can't really fail in a dangerous way....

 

[volvopaul]

Thank you all for the help

I'm happy I have repacked the stern glands correctly but I'm less convinced the engines are perfectly aligned; the problem is I need the boat out of the water to drop the shaft back slightly and check the engine is aligned with the shaft. I'll not know if that cures it until I'm back in the water and I couldn't face another season with my head in the bilges

I'll have a look at Tide Marine - are there any dangers with them I should worry about? the only thing I do like about the old glands is they can't really fail in a dangerous way....

Why do you need the boat out of the water, rope cutters maybe?, the correct way to align any engine install is when the boats in the water not out as the hull flexes moving the engine beds.

You may find after all these years that grooves have been scored in the shafts where the packing rubs to seal, so its new shafts, also shafts wear on both p bracket and gland cutlass bearings so there isnt much you can do other than fit new shafts, some boats have the same tapers both ends in which case you can reverse the shafts , but not in your case as the coupling end is parrallel with its clamp/split coupling.

If no cutters fitted just slacken the sterngland nuts, rotate the shaft pushing it back off the 6 bolts, you may even find the engine drops slightly after this, simply wind up the nuts on all 4 mounts to the correct height, then use feeler gauges on the bolt with the dome end usually painted red and set up the engine from scratch, easier if there is 2 of you, then repack the gland.

Is the water feed tube from the oil cooler clear? if no water is being pumped to the gland it maybe the fact that the packing is being burnt out on rotation.

 

[Tranona]

I'll have a look at Tide Marine - are there any dangers with them I should worry about? the only thing I do like about the old glands is they can't really fail in a dangerous way....

No. They are as secure as you can get as the seal is made by two water cooled lip seals around the shaft. They may eventually wear and drip, but not fail catastrophically. The seals are replaceable items.

 

[Bandit]

Alignment, as a first test run the boat and observe the shafts running at tickover and through the range to cruising speed and see if there is much movement or whip.

If you are pretty happy with this you could release the coupling bolts and see if the shaft springs in any particular direction, as an indicator of algnment. Rope cutters mean you cant do it afloat.

Modern glass fibre boat providing they are lowered and properly supported ashore do not flex much.

If you are going to fita differnet type of stern gland , you cant do it in the water anyway.

When were the cutless bearings and shafts last checked for wear? What condition are the engine mounts in ?

If the cutless bearings had not been changed in three or more years and I was going to change stern gland

Depending on cutless wear in p bracket and stern tube I would probably take the oportunity of changing all the cutless bearings and realining the engines from first principles all at the same time.

Tides Marine seals will give you a dry engine room, providing you have not got leaks from other areas.